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Archive for the ‘Efficacy of Anti-Tumor T Cells’ Category

Gender affects the prevalence of the cancer type, Volume 2 (Volume Two: Latest in Genomics Methodologies for Therapeutics: Gene Editing, NGS and BioInformatics, Simulations and the Genome Ontology), Part 1: Next Generation Sequencing (NGS)

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

Gender of a person can affect the kinds of cancer-causing mutations they develop, according to a genomic analysis spanning nearly 2,000 tumours and 28 types of cancer. The results show striking differences in the cancer-causing mutations found in people who are biologically male versus those who are biologically female — not only in the number of mutations lurking in their tumours, but also in the kinds of mutations found there.

 

Liver tumours from women were more likely to carry mutations caused by a faulty system of DNA mending called mismatch repair, for instance. And men with any type of cancer were more likely to exhibit DNA changes thought to be linked to a process that the body uses to repair DNA with two broken strands. These biases could point researchers to key biological differences in how tumours develop and evolve across sexes.

 

The data add to a growing realization that sex is important in cancer, and not only because of lifestyle differences. Lung and liver cancer, for example, are more common in men than in women — even after researchers control for disparities in smoking or alcohol consumption. The source of that bias, however, has remained unclear.

In 2014, the US National Institutes of Health began encouraging researchers to consider sex differences in preclinical research by, for example, including female animals and cell lines from women in their studies. And some studies have since found sex-linked biases in the frequency of mutations in protein-coding genes in certain cancer types, including some brain cancers and advanced melanoma.

 

But the present study is the most comprehensive study of sex differences in tumour genomes so far. It looks at mutations not only in genes that code for proteins, but also in the vast expanses of DNA that have other functions, such as controlling when genes are turned on or off. The study also compares male and female genomes across many different cancers, which can allow researchers to pick up on additional patterns of DNA mutations, in part by increasing the sample sizes.

 

Researchers analysed full genome sequences gathered by the International Cancer Genome Consortium. They looked at differences in the frequency of 174 mutations known to drive cancer, and found that some of these mutations occurred more frequently in men than in women, and vice versa. When they looked more broadly at the loss or duplication of DNA segments in the genome, they found 4,285 sex-biased genes spread across 15 chromosomes.

 

There were also differences found when some mutations seemed to arise during tumour development, suggesting that some cancers follow different evolutionary paths in men and women. Researchers also looked at particular patterns of DNA changes. Such patterns can, in some cases, reflect the source of the mutation. Tobacco smoke, for example, leaves behind a particular signature in the DNA.

 

Taken together, the results highlight the importance of accounting for sex, not only in clinical trials but also in preclinical studies. This could eventually allow researchers to pin down the sources of many of the differences found in this study. Liver cancer is roughly three times as common in men as in women in some populations, and its incidence is increasing in some countries. A better understanding of its aetiology may turn out to be really important for prevention strategies and treatments.

 

References:

 

https://www.nature.com/articles/d41586-019-00562-7?utm_source=Nature+Briefing

 

https://www.nature.com/news/policy-nih-to-balance-sex-in-cell-and-animal-studies-1.15195

 

https://www.ncbi.nlm.nih.gov/pubmed/26296643

 

https://www.biorxiv.org/content/10.1101/507939v1

 

https://www.ncbi.nlm.nih.gov/pubmed/25985759

 

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Immunoediting can be a constant defense in the cancer landscape

Immuno-editing can be a constant defense in the cancer landscape, Volume 2 (Volume Two: Latest in Genomics Methodologies for Therapeutics: Gene Editing, NGS and BioInformatics, Simulations and the Genome Ontology), Part 1: Next Generation Sequencing (NGS)

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

There are many considerations in the cancer immunoediting landscape of defense and regulation in the cancer hallmark biology. The cancer hallmark biology in concert with key controls of the HLA compatibility affinity mechanisms are pivotal in architecting a unique patient-centric therapeutic application. Selection of random immune products including neoantigens, antigens, antibodies and other vital immune elements creates a high level of uncertainty and risk of undesirable immune reactions. Immunoediting is a constant process. The human innate and adaptive forces can either trigger favorable or unfavorable immunoediting features. Cancer is a multi-disease entity. There are multi-factorial initiators in a certain disease process. Namely, environmental exposures, viral and / or microbiome exposure disequilibrium, direct harm to DNA, poor immune adaptability, inherent risk and an individual’s own vibration rhythm in life.

 

When a human single cell is crippled (Deranged DNA) with mixed up molecular behavior that is the initiator of the problem. A once normal cell now transitioned into full threatening molecular time bomb. In the modeling and creation of a tumor it all begins with the singular molecular crisis and crippling of a normal human cell. At this point it is either chop suey (mixed bit responses) or a productive defensive and regulation response and posture of the immune system. Mixed bits of normal DNA, cancer-laden DNA, circulating tumor DNA, circulating normal cells, circulating tumor cells, circulating immune defense cells, circulating immune inflammatory cells forming a moiety of normal and a moiety of mess. The challenge is to scavenge the mess and amplify the normal.

 

Immunoediting is a primary push-button feature that is definitely required to be hit when it comes to initiating immune defenses against cancer and an adaptation in favor of regression. As mentioned before that the tumor microenvironment is a “mixed bit” moiety, which includes elements of the immune system that can defend against circulating cancer cells and tumor growth. Personalized (Precision-Based) cancer vaccines must become the primary form of treatment in this case. Current treatment regimens in conventional therapy destroy immune defenses and regulation and create more serious complications observed in tumor progression, metastasis and survival. Commonly resistance to chemotherapeutic agents is observed. These personalized treatments will be developed in concert with cancer hallmark analytics and immunocentrics affinity and selection mapping. This mapping will demonstrate molecular pathway interface and HLA compatibility and adaptation with patientcentricity.

References:

 

https://www.linkedin.com/pulse/immunoediting-cancer-landscape-john-catanzaro/

 

https://www.cell.com/cell/fulltext/S0092-8674(16)31609-9

 

https://www.researchgate.net/publication/309432057_Circulating_tumor_cell_clusters_What_we_know_and_what_we_expect_Review

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4190561/

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5840207/

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5593672/

 

https://www.frontiersin.org/articles/10.3389/fimmu.2018.00414/full

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5593672/

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4190561/

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4388310/

 

https://www.linkedin.com/pulse/cancer-hallmark-analytics-omics-data-pathway-studio-review-catanzaro/

 

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Immunotherapy may help in glioblastoma survival

Immunotherapy may help in glioblastoma survival, Volume 2 (Volume Two: Latest in Genomics Methodologies for Therapeutics: Gene Editing, NGS and BioInformatics, Simulations and the Genome Ontology), Part 1: Next Generation Sequencing (NGS)

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

Glioblastoma is the most common primary malignant brain tumor in adults and is associated with poor survival. But, in a glimmer of hope, a recent study found that a drug designed to unleash the immune system helped some patients live longer. Glioblastoma powerfully suppresses the immune system, both at the site of the cancer and throughout the body, which has made it difficult to find effective treatments. Such tumors are complex and differ widely in their behavior and characteristics.

 

A small randomized, multi-institution clinical trial was conducted and led by researchers at the University of California at Los Angeles involved patients who had a recurrence of glioblastoma, the most common central nervous system cancer. The aim was to evaluate immune responses and survival following neoadjuvant and/or adjuvant therapy with pembrolizumab (checkpoint inhibitor) in 35 patients with recurrent, surgically resectable glioblastoma. Patients who were randomized to receive neoadjuvant pembrolizumab, with continued adjuvant therapy following surgery, had significantly extended overall survival compared to patients that were randomized to receive adjuvant, post-surgical programmed cell death protein 1 (PD-1) blockade alone.

 

Neoadjuvant PD-1 blockade was associated with upregulation of T cell– and interferon-γ-related gene expression, but downregulation of cell-cycle-related gene expression within the tumor, which was not seen in patients that received adjuvant therapy alone. Focal induction of programmed death-ligand 1 in the tumor microenvironment, enhanced clonal expansion of T cells, decreased PD-1 expression on peripheral blood T cells and a decreasing monocytic population was observed more frequently in the neoadjuvant group than in patients treated only in the adjuvant setting. These findings suggest that the neoadjuvant administration of PD-1 blockade enhanced both the local and systemic antitumor immune response and may represent a more efficacious approach to the treatment of this uniformly lethal brain tumor.

 

Immunotherapy has not proved to be effective against glioblastoma. This small clinical trial explored the effect of PD-1 blockade on recurrent glioblastoma in relation to the timing of administration. A total of 35 patients undergoing resection of recurrent disease were randomized to either neoadjuvant or adjuvant pembrolizumab, and surgical specimens were compared between the two groups. Interestingly, the tumoral gene expression signature varied between the two groups, such that those who received neoadjuvant pembrolizumab displayed an INF-γ gene signature suggestive of T-cell activation as well as suppression of cell-cycle signaling, possibly consistent with growth arrest. Although the study was not powered for efficacy, the group found an increase in overall survival in patients receiving neoadjuvant pembrolizumab compared with adjuvant pembrolizumab of 13.7 months versus 7.5 months, respectively.

 

In this small pilot study, neoadjuvant PD-1 blockade followed by surgical resection was associated with intratumoral T-cell activation and inhibition of tumor growth as well as longer survival. How the drug works in glioblastoma has not been totally established. The researchers speculated that giving the drug before surgery prompted T-cells within the tumor, which had been impaired, to attack the cancer and extend lives. The drug didn’t spur such anti-cancer activity after the surgery because those T-cells were removed along with the tumor. The results are very important and very promising but would need to be validated in much larger trials.

 

References:

 

https://www.washingtonpost.com/health/2019/02/11/immunotherapy-may-help-patients-with-kind-cancer-that-killed-john-mccain/?noredirect=on&utm_term=.e1b2e6fffccc

 

https://www.ncbi.nlm.nih.gov/pubmed/30742122

 

https://www.practiceupdate.com/content/neoadjuvant-anti-pd-1-immunotherapy-promotes-immune-responses-in-recurrent-gbm/79742/37/12/1

 

https://www.esmo.org/Oncology-News/Neoadjuvant-PD-1-Blockade-in-Glioblastoma

 

https://neurosciencenews.com/immunotherapy-glioblastoma-cancer-10722/

 

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TWEETS by @pharma_BI and @AVIVA1950 at #IESYMPOSIUM – @kochinstitute 2019 #Immune #Engineering #Symposium, 1/28/2019 – 1/29/2019

Real Time Press Coverage: Aviva Lev-Ari, PhD, RN

2.1.3.4

2.1.3.4   TWEETS by @pharma_BI and @AVIVA1950 at #IESYMPOSIUM – @kochinstitute 2019 #Immune #Engineering #Symposium, 1/28/2019 – 1/29/2019, Volume 2 (Volume Two: Latest in Genomics Methodologies for Therapeutics: Gene Editing, NGS and BioInformatics, Simulations and the Genome Ontology), Part 2: CRISPR for Gene Editing and DNA Repair

eProceedings for Day 1 and Day 2

LIVE Day One – Koch Institute 2019 Immune Engineering Symposium, January 28, 2019, Kresge Auditorium, MIT

https://pharmaceuticalintelligence.com/2019/01/28/live-day-one-koch-institute-2019-immune-engineering-symposium-january-28-2019-kresge-auditorium-mit/

LIVE Day Two – Koch Institute 2019 Immune Engineering Symposium, January 29, 2019, Kresge Auditorium, MIT

https://pharmaceuticalintelligence.com/2019/01/29/live-day-two-koch-institute-2019-immune-engineering-symposium-january-29-2019-kresge-auditorium-mit/

  1. AMAZING Conference I covered in Real Time

  2. Aviv Regev Melanoma: malignant cells with resistance in cold niches in situ cells express the resistance program pre-treatment: resistance UP – cold Predict checkpoint immunotherapy outcomes CDK4/6 abemaciclib in cell lines

  3. Aviv Regev, a cell-cell interactions from variations across individuals Most UC-risk genes are cell type specificVariation – epithelial cell signature – organize US GWAS into cell type spec

  4. Diane Mathis Age-dependent Treg and mSC changes – Linear with increase in age Sex-dependent Treg and mSC changes – Female Treg loss in cases of Obesity leading to fibrosis Treg keep IL-33-Producing mSCs under rein Lean tissue/Obese tissue

  5. Martin LaFleur Loss of Ptpn2 enhances CD8+ T cell responses to LCMV and Tumors PTpn2 deletion in the immune system enhanced tumor immunity CHIME enables in vivo screening

  6. Alex Shalek Identifying and rationally modulating cellular drivers of enhanced immunity T Cells, Clusters Expression of Peak and Memory Immunotherapy- Identifying Dendritic cells enhanced in HIV-1 Elite Controllers

  7.   Retweeted

    Onward: our own Michael Birnbaum, who assures us that if you feel like you’re an immunoengineer, then you ARE one!

  8. Glenn Dranoff Adenosine level in blood or tissue very difficult to measure in blood even more than in tissue – NIR178 + PDR 001 Monotherapy (NIR178) combine with PD receptor blockage (PDR) show benefit A alone vs A+B in Clinical trial

  9. Glenn Dranoff PD-L1 blockade elicits responses in some patients: soft part sarcoma LAG-3 combined with PD-1 – human peripheral blood tumor TIM-3 key regulator of T cell and Myeloid cell function: correlates in the TCGA DB myeloid

  10. Glenn Dranoff Institute for Biomedical Research of Neurologic toxicities of CART t IL-6 activation AML – complete response – weekly dose of XmAb CD123X CD3 bispecific antibody anti tumor effect

  11. of protective HLA-DR4 effects outside of “peptide anchor” residues Class I MHC – HLA-E down regulate T and NK cells Receptor Binding: Positional preferences noted for NKG2A

  12. Yvonne Chen Activation of t Cell use CAR t Engineer CAR-T to respond to soluble form of antigens: CD19 CAR Responds to soluble CD19 GFP MCAR responds to Dimeric GFP “Tumor microenvironment is a scary place”

  13. Yvonne Chen Do we need a ligand to be a dimers? Co-expressed second-generation TGF-beta signaling

  14. Yvonne Chen “Engineering smarter and stronger T cells for cancer immunotherapy” OR-Gate cause no relapse – Probing limits of modularity in CAR Design Bispecific CARs are superior to DualCAR: One vs DualCAR (some remained single CAR)

  15.   Retweeted

    Ending the 1st session is Cathy Wu of detailing some amazing work on vaccination strategies for melanoma and glioblastoma patients. They use long peptides engineered from tumor sequencing data.

  16.   Retweeted

    Some fancy imaging: Duggan gives a nice demo of how dSTORM imaging works using a micropatterend image of Kennedy Institute for Rheumatology! yay!

  17.   Retweeted

    Lots of interesting talks in the second session of the – effects of lymphoangiogenesis on anti-tumor immune responses, nanoparticle based strategies to improve bNAbs titers/affinity for HIV therapy, and IAPi cancer immunotherapy

  18.   Retweeted

    Looking forward to another day of the . One more highlight from yesterday – from our own lab showcased her work developing cytokine fusions that bind to collagen, boosting efficacy while drastically reducing toxicities

  19.   Retweeted

    Members of our cell therapy team were down the street today at neighboring for the presented by .

  20.   Retweeted

    He could have fooled me that he is, in fact, an immunologist!

  21.  
  22.   Retweeted

    Come and say Hi! ACIR will be back tomorrow at the Immune Engineering Symposium at MIT. Learn more at . . And stay tuned to read our summary of the talks on Feb 6.

  23. Facundo Batista @MGH # in BG18 Germline Heavy CHain (BG18-gH) High-mannose patch – mice exhibit normal B cell development B cells from naive human germline BG18-gH bind to GT2 immunogen

  24. Preeti Sharma, U Illinois T cell receptor and CAR-T engineering TCR engineering for Targeting glycosylated cancer antigens Nornal glycosylation vs Aberrant Engineering 237-CARs libraries with conjugated (Tn-OTS8) against Tn-antigend In vitro

  25. Bryan Bryson Loss of polarization potential: scRNAseq reveals transcriptional differences Thioredoxin facilitates immune response to Mtb is a marker of an inflammatory macrophage state functional spectrum of human microphages

  26. Bryan Bryson macrophage axis in Mycobacterium tuberculosis Building “libraries” – surface marker analysis of Microphages Polarized macrophages are functionally different quant and qual differences History of GM-CSF suppresses IL-10

  27. Jamie Spangler John Hopkins University “Reprogramming anti-cancer immunity RESPONSE through molecular engineering” De novo IL-2 potetiator in therapeutic superior to the natural cytokine by molecular engineering mimicking other cytokines

  28. Jamie Spangler JES6-1 Immunocytokine – inhibiting melanoma Engineering a Treg cell-biased immunocytokine double mutant immunocytokine shows enhanced IL-2Ralpha exchange Affinity De Novo design of a hyper-stable, effector biased IL-2

  29. , Volume Five: in of Cardiovascular Diseases. On com since 12/23/2018

  30. Michael Dustin ESCRT pathway associated with synaptic ectosomes Locatization, Microscopy Cytotoxic T cell granules CTLs release extracellular vescicles similar to T Helper with perforin and granzyme – CTL vesicles kill targets

  31. Michael Dustin Delivery of T cell Effector function through extracellular vesicles Synaptic ectosome biogenisis Model: T cells: DOpamine cascade in germinal cell delivered to synaptic cleft – Effector CD40 – Transfer is cooperative

  32. Michael Dustin Delivery of T cell Effector function through extracellular vesicles Laterally mobile ligands track receptor interaction ICAM-1 Signaling of synapse – Sustain signaling by transient in microclusters TCR related Invadipodia

  33. Mikael Pittet @MGH Myeloid Cells in Cancer Indirect mechanism AFTER a-PD-1 Treatment IFN-gamma Sensing Fosters IL-12 & therapeutic Responses aPD-1-Mediated Activation of Tumor Immunity – Direct activation and the ‘Licensing’ Model

  34. Stefani Spranger KI Response to checkpoint blockade Non-T cell-inflamed – is LACK OF T CELL INFILTRATION Tumor CD103 dendritic cells – Tumor-residing Batf3-drivenCD103 Tumor-intrinsic Beta-catenin mediates lack of T cell infiltration

  35. Max Krummel Gene expression association between two genes: and numbers are tightly linked to response to checkpoint blockage IMMUNE “ACCOMODATION” ARCHYTYPES: MYELOID TUNING OF ARCHITYPES Myeloid function and composition

  36. Noor Momin, MIT Lumican-cytokines improve control of distant lesions – Lumican-fusion potentiates systemic anti-tumor immunity

    Translate Tweet

  37. Noor Momin, MIT Lumican fusion to IL-2 improves treatment efficacy reduce toxicity – Anti-TAA mAb – TA99 vs IL-2 Best efficacy and least toxicity in Lumican-MSA-IL-2 vs MSA-IL2 Lumican synergy with CAR-T

  38.   Retweeted

    excited to attend the immune engineering symposium this week! find me there to chat about and whether your paper could be a good fit for us! 🦠🧬🔬🧫📖

  39.   Retweeted

    Bob Schreiber and Tyler Jacks kicked off the with 2 great talks on the role of Class I and Class II neo-Ag in tumor immunogenicity and how the tumor microenvironment alters T cell responsiveness to tumors in vivo

  40.   Retweeted

    Scott Wilson from gave a fantastic talk on glycopolymer conjugation to antigens to improve trafficking to HAPCs and enhanced tolerization in autoimmunity models. Excited to learn more about his work at his faculty talk!

  41. AMAZING Symposinm

  42.   Retweeted

    Immune Engineering Symposium at MIT is underway!

  43.   Retweeted

    ACIR is excited to be covering the Immune Engineering Symposium at MIT on January 28-29. Learn more at .

  44. Tyler Jacks talk was outstanding, Needs be delivered A@TED TALKs, needs become contents in the curriculum of Cell Biology graduate seminar as an Online class. BRAVO

  45.   Retweeted

    Here we go!! Today and tomorrow the tippity top immunologists converge at

  46.   Retweeted

    Exciting start to this year’s Immune Engineering Symposium put on by at . A few highlights from the first section…

  47. Stephanie Dougan (Dana-Farber Cancer Institute) Dept. Virology IAPi outperforms checkpoint blockade in T cell cold tumors reduction of tumor burden gencitabine cross-presenting DCs and CD8 T cells – T cell low 6694c2

  48. Darrell Irvine (MIT, Koch Institute; HHMI) Engineering follicle delivery through synthetic glycans: eOD-60mer nanoparticles vs Ferritin-trimer 8-mer (density dependent)

  49. Darrell Irvine (MIT, Koch Institute; HHMI) GC targeting is dependent on complement component CIQ – activation: Mannose-binding lectins recognize eOD-60mer but not eOD monomer or trimers

  50. Melody Swartz (University of Chicago) Lymphangiogenesis attractive to Native T cells, in VEGF-C tumors T cell homing inhibitors vs block T cell egress inhibitors – Immunotherapy induces T cell killing

  51. Cathy Wu @MGH breakthrough for Brain Tumor based neoantigen-specific T cell at intracranial site Single cells brain tissue vs single cells from neoantigen specific T cells – intratumoral neoantigen-specific T cells: mutARGAP35-spacific

  52. Cathy Wu (Massachusetts General Hospital) – CoFounder of NEON Enduring complete radiographic responses after + alpha-PD-1 treatment (anti-PD-1) NeoVax vs IVAC Mutanome for melanoma and Glioblastoma clinical trials

  53. , U of Chicago IV INJECTION: OVAALBUMIN OVA-P(GALINAC), P(GLCNAC), SUPRESS T CELL RESPONSE Abate T cells response – Reduced cytokine production & increased -regs

  54. Interrogating markers of T cell dysfunction – chance biology of cells by CRISPR – EGR2 at 2 weeks dysfuntioning is reduced presence of EDR2 mutant class plays role in cell metabolism cell becomes functional regulator CD8 T cell

  55. Bob Schreiber (Wash University of St. Louis) Optimal CD8+ T cells mediated to T3 require CD4+ T help

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LIVE Day Two – Koch Institute 2019 Immune Engineering Symposium, January 29, 2019, Kresge Auditorium, MIT

 

Real Time Press Coverage: Aviva Lev-Ari, PhD, RN

#IESYMPOSIUM @pharma_BI @AVIVA1950

 

MISSION The mission of the Koch Institute (KI) is to apply the tools of science and technology to improve the way cancer is detected, monitored, treated and prevented.

APPROACH We bring together scientists and engineers – in collaboration with clinicians and industry partners – to solve the most intractable problems in cancer. Leveraging MIT’s strengths in technology, the life sciences and interdisciplinary research, the KI is pursuing scientific excellence while also directly promoting innovative ways to diagnose, monitor, and treat cancer through advanced technology.

HISTORY The Koch Institute facility was made possible through a $100 million gift from MIT alumnus David H. Koch. Our new building opened in March 2011, coinciding with MIT’s 150th anniversary. Our community has grown out of the MIT Center for Cancer Research (CCR), which was founded in 1974 by Nobel Laureate and MIT Professor Salvador Luria, and is one of seven National Cancer Institute-designated basic (non-clinical) research centers in the U.S.

https://ki.mit.edu/files/ki/cfile/news/presskit/KI_Fact_Sheet_-_February_2018.pdf

January 28-29, 2019
Kresge Auditorium, MIT

Biological, chemical, and materials engineers are engaged at the forefront of immunology research. At their disposal is an analytical toolkit honed to solve problems in the petrochemical and materials industries, which share the presence of complex reaction networks, and convective and diffusive molecular transport. Powerful synthetic capabilities have also been crafted: binding proteins can be engineered with effectively arbitrary specificity and affinity, and multifunctional nanoparticles and gels have been designed to interact in highly specific fashions with cells and tissues. Fearless pursuit of knowledge and solutions across disciplinary boundaries characterizes this nascent discipline of immune engineering, synergizing with immunologists and clinicians to put immunotherapy into practice.

The 2019 symposium will include two poster sessions and four abstract-selected talks. Abstracts should be uploaded on the registration page. Abstract submission deadline is November 15, 2018. Registration closes December 14.

Featuring on Day 2, 1/29, 2019:

Session IV

Moderator: Michael Birnbaum, Koch Institute, MIT

 

Jamie Spangler (John Hopkins University)

“Reprogramming anti-cancer immunity through molecular engineering”

  • Reprogramming anti-cancer immunity response through molecular engineering”
  • Cytokines induce receptor dimerization
  • Clinical Use of cytokines: Pleiotropy, expression and stability isssues
  • poor pharmacological properties
  • cytokine therapy: New de novo protein using computational methods
  • IL-2 signals through a dimeric nad a trimeric receptor complex
  • IL-2 pleiotropy hinders its therapeutic efficacy
  • IL-2 activate immunosuppression
  • potentiation of cytokine activity by anti-IL-2 antibody selectivity
  • Cytokine binding – Antibodies compete with IL-2 receptor subunits
  • IL-2Ralpha, IL-2 Rbeta: S4B6 mimickry of alpha allosterically enhances beta
  • stimulates both Effectors and T-regs
  • JES6-1 immunocomplex selectively stimulates IL-2Ralpha cells
  • Engineering translational single-chain cytokine/antibody fusion
  • Engineering an EFFECTOR cell-based immunocytokine (602)
  • JES6-1 Immunocytokine – inhibiting melanoma
  • Engineering a Treg cell-biased immunocytokine
  • double mutant immunocytokine shows enhanced IL-2Ralpha exchange
  • Affinity  – molecular eng De Novo design of a hyper-stable, effector biased IL-2
  • De novo IL-2 poteniator in therapeutic superior to the natural cytokine by molecular engineering

 

Bryan Bryson (MIT, Department of Biological Engineering)

“Exploiting the macrophage axis in Mycobacterium tuberculosis (Mtb) infection”

  • TB  – who develop Active and why?
  • Immunological life cycle of Mtb
  • Global disease Mtb infection outcome varies within individual host
  • lesion are found by single bacteria
  • What are the cellular players in immune success
  • MACROPHAGES – molecular signals enhancing Mtb control of macrophages
  • modeling the host- macrophages are plastic and polarize
  • Building “libraries” – surface marker analysis of Microphages
  • Polarized macrophages are functionally different
  • quant and qual differences
  • History of GM-CSF suppresses IL-10
  • Loss of polarization potential: scRNAseq reveals transcriptional differences Thioredoxin facilitates immune response to Mtb is a marker of an inflammatory macrophage state
  • functional spectrum of human microphages

 

Facundo Batista (Ragon Institute (HIV Research) @MGH, MIT and Harvard)

“Vaccine evaluation in rapidly produced custom humanized mouse models”

  • Effective B cell activation requires 2 signals Antigen and binding to T cell
  • VDJ UCA (Unmutated common Ancestor)
  • B Cell Receptor (BCR) co-receptors and cytoskeleton
  • 44% in Women age 24-44
  • Prototype HIV broadly neutralizing Antibodies (bnAb) do not bind to Env protein – Immunogen design and validation
  • Target Identification –>> Immunogen Design –>>> Immunogen Validation
  • Human Ig Knock-ins [Light variable 5′ chain length vs 7′ length] decisive to inform immunogenicity – One-Step CRISPR approach does not require ES cell work
  • Proof of principle with BG18 Germline Heavy Chain (BG18-gH) High-mannose patch – mice exhibit normal B cell development
  • B cells from naive human germline BG18-gH bind to GT2 immunogen
  • GT2-nanoparticle 9NP) induces robust BG18-gH-500 cells: CD45.2 GL7 IgD
  • Interrogate immune response for HIV, Malaria, Zika, Flu

 

Session V

Moderator: Dane Wittrup, Koch Institute, MIT

 

Yvonne Chen (University of California, Los Angeles)

“Engineering smarter and stronger T cells for cancer immunotherapy”

  • Adoptive T-Cell Therapy
  • Tx for Leukemia – Tumor Antigen escape fro CAR T-cell therapy, CD19/CD20 OR-Gate CARs for prevention of antigen escape – 15 month of development
  • reduce probability of antigen escape due to two antigen CD19/CD20: Probing limits of modularity in CAR design
  • In vivo model: 75% wild type & 25% CD19 – relapse occur in the long term, early vs late vs no relapse: Tx with CAR t had no relapse
  • OR-Gate cause no relapse – Probing limits of modularity in CAR Design
  • Bispecific CARs are superior to DualCAR: One vs DualCAR (some remained single CAR)
  • Bispecific CARs exhibit superior antigen-stimulation capacity – OR-Gate CAR Outperforms Single-Input CARs
  • Lymphoma and Leukemia are 10% of all Cancers
  • TGF-gamma Rewiring T Cell Response
  • Activation of t Cell use CAR t
  • Engineer CAR-T to respond to soluble form of antigens: CD19 CAR Responds to soluble CD19
  • GFP MCAR responds to Dimeric GFP
  • “Tumor microenvironment is a scary place”

 

Michael Birnbaum, MIT, Koch Institute

“A repertoire of protective tumor immunity”

  • Decoding T and NK cell recognition – understanding immune recognition and signaling function for reprogramming the Immune system – Neoantigen vaccine pipeline
  • Personal neoantigen vax improve immunotherapy
  • CLASS I and CLASS II epitomes: MHC prediction performance – more accurate for CLASS I HLA polymorphisms
  • Immune Epitope DB and Analysis Resources 448,630 Peptide Epitomes
  • B cell assay: 413,000
  • T cell assays: 313,000
  • peptide sequence relationships – naturally occurring antigen predictions
  • Cleavable pMHC yeast display to determine peptide loading
  • HLA-DR4 libraries enrich a large collection of peptides: 96000 1/5 of entire peptide DB: Enriched motif, prediction algorithms
  • Algorithmic false negatives vs peptide concentration(nM)
  • HLA-DR4 effects outside of “peptide anchor” residues
  • Class I MHC – HLA-E down regulate T and NK cells
  • Receptor Binding: Positional preferences noted for NKG2A
  • Training data vs Algorithmic approach
  • Globally oriented –
  • TCR sequencing – TCR pairings – Multicell-per-well sequencing
  • MAD-HYPE algorithm

 

Glenn Dranoff, Novartis Institute for Biomedical Research

“Mechnism of protective tumor immunity”

  • Immune checkpoint blockade elicit 10 years survival in melanoma
  • PD-1 blockage esophageal carcinoma effective showing survival
  • renal cells, bladder
  • 20% benefit from Immuno therapy – CTLA-4 toxicity is high small % patient benefit
  • PD-1/PD-L1 anti CLTA-4 mAbs
  • solid tumors challenging
  • Requirement for effective IO – Tumor receptivity to immune infiltration
  • modulation
  • Novartis IO in the clinic: multiple tumor immune escape – complexity
  • Approach: focus trials aimed to learn immune response complementation groups manipulate into response
  • work with Engineering for delivery nimble to generate new data
  • Translational research in the clinic
  • CAR T cells
  • B cell malignancies are ideal targets for CAR T cells
  • Relapsed/Refractory – pediatric ALL refractory advanced to no relapse – complete response 80% – 6 years response
  • Antigen loss CD19 – targeting with combinatorial approach to avoid relapse
  • Large B cell lymphoma
  • Neurologic toxicities of CART t IL-6 activation
  • AML – complete response – weekly dose of XmAb CD123X CD3 bispecific antibody – protein engineering – anti tumor effect in refractory Leukemia
  • anaplastic thyroid carcinoma
  • PD-L1 blockade elicits responses in some patients: soft part sarcoma
  • LAG-3 combined with PD-1 – human peripheral blood tumor
  • TIM-3 key regulator of T cell and Myeloid cell function: correlates in the TCGA DB with myeloid
  • Adenosine level in blood or tissue very difficult to measure in blood even more than in tissue – NIR178 + PDR 001 Mono-therapy (NIR178) combine with PD receptor blockage (PDR) – shows benefit
  • A alone vs A+B in Clinical trial

 

Session VI

Moderator: Stefani Spranger, Koch Institute, MIT

 

Tim Springer, Boston Children’s Hospital, HMS

The Milieu Model for TGF-Betta Activation”

  • Protein Science – Genomics with Protein
  • Antibody Initiative – new type of antibodies not a monoclonal antibody – a different type
  • Pro TGF-beta
  • TGF-beta – not a typical cytokine it is a prodamine for Mature growth factor — 33 genes mono and heterogeneous dimers
  • Latent TGF-Beta1 crystal structure: prodomaine shields the Growth Factor
  • Mechanism od activation of pro-TGF-beta – integrin alphaVBeta 6: pro-beta1:2
  • Simulation in vivo: actin cytoskeleton cytoplasmic domain
  • LIFE CYCLE OF PROTGF-BETA
  • LRRC33 – GARP class relative
  • microglia and macrophage – link TGF-beta phenotype knock outs
  • TGF compartments of microglia separated myelination loss
  • Inhibition of TGF-beta enhances immune checkpoint
  • Loss of LRRC33-dependent TGF-beta signaling would counteract immune suppression in tumor and in slow tumor growth
  • lung metastasis of B16 in melanoma
  • immuno-histo-chemistry: LRRC33 tumor-associated myeloid cell lack cell surface proTGF-beta1
  • blocking antibodies LRRC33 mitigate toxicity on PD-L1 treatment

 

Alex Shalek, MIT, Department of Chemistry, Koch Institute

“Identifying and rationally modulating cellular drivers of enhanced immunity”

  • Balance in the Immune system
  • Profiling Granulomas  using Seq-Well 2.0
  • lung tissue in South Africa of TB patients
  • Granulomas, linking cell type abundance with burden
  • Exploring T cells Phenotypes
  • Cytotoxic & Effector ST@+ Regulatory
  • Vaccine against TB – 19% effective, only 0 IV BCG vaccination can elicit sterilizing Immunity
  • Profiling cellular response to vaccination
  • T cell gene modules across vaccine routes
  • T Cells, Clusters
  • Expression of Peak and Memory
  • Immunotherapy- Identifying Dendritic cells enhanced in HIV-1 Elite Controllers
  • moving from Observing to Engineering
  • Cellular signature: NK-kB Signaling
  • Identifying and testing Cellular Correlates of TB Protection
  • Beyond Biology: Translation research: Data sets: dosen

 

Session VII

Moderator: Stefani Spranger, Koch Institute, MIT

 

Diane Mathis, Harvard Medical School

“Tissue T-regs”

  • T reg populations in Lymphoid Non–lymphoid Tissues
  • 2009 – Treg tissue homeostasis status – sensitivity to insulin, 5-15% CD4+ T compartment
  •  transcriptome
  • expanded repertoires TCRs
  • viceral adipose tissue (VAT) –  Insulin
  • Dependencies: Taget IL-33 its I/1r/1 – encoded Receptor ST2
  • VAT up-regulate I/1r/1:ST2 Signaling
  • IL-33 – CD45 negative CD31 negative
  • mSC Production of IL-33 is Important to Treg
  • The mesenchyme develops into the tissues of the lymphatic and circulatory systems, as well as the musculoskeletal system. This latter system is characterized as connective tissues throughout the body, such as bone, muscle and cartilage. A malignant cancer of mesenchymal cells is a type of sarcoma.
  • mesenchymal Stromal Cells – mSC – some not all, VAT mSCs express IL-33
  • development of a mAb Panel for sorting the mSC Subtypes
  • Deeper transcriptome for Phenotyping of VAT mSCs
  • physiologic & pathologic perturbation
  1. Age-dependent Treg and mSC changes – Linear with increase in age
  2. Sex-dependent Treg and mSC changes – Female
  • Treg loss in cases of Obesity leading to fibrosis
  • Treg keep IL-33-Producing mSCs under rein
  • Lean tissue vs Obese tissue
  • Aged mice show poor skeletal muscle repair – it is reverses by IL-33 Injection
  • Immuno-response: target tissues systemic T reg
  • Treg and mSC

 

Aviv Regev, Broad Institute; Koch Institute

“Cell atlases as roadmaps to understand Cancer”

  • Colon disease UC – genetic underlining risk, – A single cell atlas of healthy and UC colonic mucosa inflammed and non-inflammed: Epithelial, stromal, Immune – fibroblast not observed in UC colon IAFs; IL13RA2 + IL11
  • Anti TNF responders – epithelial cells
  • Anti TNF non-responders – inflammatory monocytes fibroblasts
  • RESISTANCE to anti-cancer therapy: OSM (Inflammatory monocytes-OSMR (IAF)
  • cell-cell interactions from variations across individuals
  • Most UC-risk genes are cell type specific
  • Variation within a cell type helps predict GWAS gene functions – epithelial cell signature – organize US GWAS into cell type specific – genes in associated regions: UC and IBD

 

  • Melanoma
  • malignant cells with resistance in cold niches in situ
  • cells express the resistance program pre-treatment: resistance UP – cold
  • Predict checkpoint immunotherapy outcomes
  • CDK4/6 – computational search predict as program regulators: abemaciclib in cell lines

 

 

 

Poster Presenters

Preeti Sharma, University of Illinois

T cell receptor and CAR-T engineering – T cell therapy

  • TCR Complex: Vbeta Cbeta P2A Valpha Calpha
  • CAR-T Aga2 HA scTCR/scFv c-myc
  • Directed elovution to isolate optimal TCR or CAR
  • Eng TCR and CARt cell therapy
  • Use of TCRs against pep/MHC allows targeting a n array of cancer antigens
  • TCRs are isolated from T cell clones
  • Conventional TCR identification method vs In Vitro TCR Eng directed evolution
  • T1 and RD1 TCRs drive activity against MART-1 in CD4+ T cells
  • CD8+
  • TCR engineering for Targeting glycosylated cancer antigens
  • Normal glycosylation vs Aberrant glycosylation
  • Engineering 237-CARs  libraries with conjugated (Tn-OTS8) against multiple human Tn-antigend
  • In vitro engineering: broaden specificity to multiple peptide backbone
  • CAR engineering collaborations with U Chicago, U Wash, UPenn, Copenhagen, Germany

 

Martin LaFleur, HMS

CRISPR- Cas9 Bone marrow stem cells for Cancer Immunotherapy

  • CHIME: CHimeric IMmune Editing system
  • sgRNA-Vex
  • CHIME can be used to KO genes in multiple immune lineages
  • identify T cell intrinsic effects in the LCMV model Spleen-depleted, Spleen enhanced
  • Loss of Ptpn2 enhances CD8+ T cell responses to LCMV and Tumors
  • Ptpn2 deletion in the immune system enhanced tumor immunity
  • CHIME enables in vivo screening

 

 

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2018 Nobel Prize in Physiology or Medicine for contributions to Cancer Immunotherapy to James P. Allison, Ph.D., of the University of Texas, M.D. Anderson Cancer Center, Houston, Texas. Dr. Allison shares the prize with Tasuku Honjo, M.D., Ph.D., of Kyoto University Institute, Japan

Reporter: Aviva Lev-Ari, PhD, RN

 

See

Immune System Stimulants: Articles of Note @pharmaceuticalintelligence.com

Curators: Larry H. Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2016/05/01/immune-system-stimulants-articles-of-note-pharmaceuticalintelligence-com/

 

Immune-Oncology Molecules In Development & Articles on Topic in @pharmaceuticalintelligence.com

Curators: Stephen J Williams, PhD and Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2016/01/11/articles-on-immune-oncology-molecules-in-development-pharmaceuticalintelligence-com/

 

 

Monday, October 1, 2018

NIH grantees win 2018 Nobel Prize in Physiology or Medicine.

The 2018 Nobel Prize in Physiology or Medicine has been awarded to National Institutes of Health grantee James P. Allison, Ph.D., of the University of Texas, M.D. Anderson Cancer Center, Houston, Texas. Dr. Allison shares the prize with Tasuku Honjo, M.D., Ph.D., of Kyoto University Institute, Japan, for their discovery of cancer therapy by inhibition of negative immune regulation.

The Royal Swedish Academy of Sciences said, “by stimulating the inherent ability of our immune system to attack tumor cells this year’s Nobel Laureates have established an entirely new principle for cancer therapy.”

Dr. Allison discovered that a particular protein (CTLA-4) acts as a braking system, preventing full activation of the immune system when a cancer is emerging. By delivering an antibody that blocks that protein, Allison showed the brakes could be released. The discovery has led to important developments in cancer drugs called checkpoint inhibitors and dramatic responses to previously untreatable cancers. Dr. Honjo discovered a protein on immune cells and revealed that it also operates as a brake, but with a different mechanism of action.

“Jim’s work was pivotal for cancer therapy by enlisting our own immune systems to launch an attack on cancer and arrest its development,” said NIH Director Francis S. Collins, M.D., Ph.D. “NIH is proud to have supported this groundbreaking research.”

Dr. Allison has received continuous funding from NIH since 1979, receiving more than $13.7 million primarily from NIH’s National Cancer Institute (NCI) and National Institute of Allergy and Infectious Diseases (NIAID).

“This work has led to remarkably effective, sometime curative, therapy for patients with advanced cancer, who we were previously unable to help,” said NCI Director Ned Sharpless, M.D. “Their findings have ushered in the era of cancer immunotherapy, which along with surgery, radiation and cytotoxic chemotherapy, represents a ‘fourth modality’ for treating cancer. A further understanding of the biology underlying the immune system and cancer has the potential to help many more patients.”

“Dr. Allison’s elegant and groundbreaking work in basic immunology over four decades and its important applicability to cancer is a vivid demonstration of the critical nature of interdisciplinary biomedical research supported by NIH,” says NIAID Director Anthony S. Fauci, M.D.

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

SOURCE

https://www.nih.gov/news-events/news-releases/nih-grantees-win-2018-nobel-prize-physiology-or-medicine

 

Dr. Lev-Ari covered in person the following curated articles about James Allison, PhD since his days at University of California, Berkeley, including the prizes awarded prior to the 2018 Nobel Prize in Physiology.

 

2018 Albany Medical Center Prize in Medicine and Biomedical Research goes to NIH’s Dr. Rosenberg and fellow immunotherapy researchers James P. Allison, Ph.D., and Carl H. June, M.D.

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2018/08/15/2018-albany-medical-center-prize-in-medicine-and-biomedical-research-goes-to-nihs-dr-rosenberg-and-fellow-immunotherapy-researchers-james-p-allison-ph-d-and-carl-h-june-m-d/

 

Lectures by The 2017 Award Recipients of Warren Alpert Foundation Prize in Cancer Immunology, October 5, 2017, HMS, 77 Louis Paster, Boston

REAL TIME Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2017/09/08/lectures-by-the-2017-award-recipients-of-warren-alpert-foundation-prize-in-cancer-immunology-october-5-2017-hms-77-louis-paster-boston/

 

Cancer-free after immunotherapy treatment: Treating advanced colon cancer – targeting KRAS gene mutation by tumor-infiltrating lymphocytes (TILs) and Killer T-cells (NK)

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2016/12/08/cancer-free-after-immunotherapy-treatment-treating-advanced-colon-cancer-targeting-kras-gene-mutation-by-tumor-infiltrating-lymphocytes-tils-and-killer-t-cells-nk/

 

New Class of Immune System Stimulants: Cyclic Di-Nucleotides (CDN): Shrink Tumors and bolster Vaccines, re-arm the Immune System’s Natural Killer Cells, which attack Cancer Cells and Virus-infected Cells

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2016/04/24/new-class-of-immune-system-stimulants-cyclic-di-nucleotides-cdn-shrink-tumors-and-bolster-vaccines-re-arm-the-immune-systems-natural-killer-cells-which-attack-cancer-cells-and-virus-inf/

 

UC Berkeley research led to Nobel Prize-winning immunotherapy

Immunologist James P. Allison today shared the 2018 Nobel Prize in Physiology or Medicine for groundbreaking work he conducted on cancer immunotherapy at UC Berkeley during his 20 years as director of the campus’s Cancer Research Laboratory.

James Allison

James Allison, who for 20 years was a UC Berkeley immunologist conducting fundamental research on cancer, is now at the M.D. Anderson Cancer Center in Houston, Texas.

Now at the University of Texas M.D. Anderson Cancer Center in Houston, Allison shared the award with Tasuku Honjo of Kyoto University in Japan “for their discovery of cancer therapy by inhibition of negative immune regulation.”

Allison, 70, conducted basic research on how the immune system – in particular, a cell called a T cell – fights infection. His discoveries led to a fundamentally new strategy for treating malignancies that unleashes the immune system to kill cancer cells. A monoclonal antibody therapy he pioneered was approved by the Food and Drug Administration in 2011 to treat malignant melanoma, and spawned several related therapies now being used against lung, prostate and other cancers.

“Because this approach targets immune cells rather than specific tumors, it holds great promise to thwart diverse cancers,” the Lasker Foundation wrote when it awarded Allison its 2015 Lasker-DeBakey Clinical Medical Research Award.

Allison’s work has already benefited thousands of people with advanced melanoma, a disease that used to be invariably fatal within a year or so of diagnosis. The therapy he conceived has resulted in elimination of cancer in a significant fraction of patients for a decade and counting, and it appears likely that many of these people are cured.

“Targeted therapies don’t cure cancer, but immunotherapy is curative, which is why many consider it the biggest advance in a generation,” Allison said in a 2015 interview. “Clearly, immunotherapy now has taken its place along with surgery, chemotherapy and radiation as a reliable and objective way to treat cancer.”

“We are thrilled to see Jim’s work recognized by the Nobel Committee,” said Russell Vance, the current director of the Cancer Research Laboratory and a UC Berkeley professor of molecular and cell biology. “We congratulate him on this highly deserved honor. This award is a testament to the incredible impact that the fundamental research Jim conducted at Berkeley has had on the lives of cancer patients”

“I don’t know if I could have accomplished this work anywhere else than Berkeley,” Allison said. “There were a lot of smart people to work with, and it felt like we could do almost anything. I always tell people that it was one of the happiest times of my life, with the academic environment, the enthusiasm, the students, the faculty.”

In this video about UC Berkeley’s new Immunotherapeutics and Vaccine Research Initiative (IVRI), Allison discusses his groundbreaking work on cancer immunotherapy.

In fact, Allison was instrumental in creating the research environment of the current Department of Molecular and Cell Biology at UC Berkeley as well as the department’s division of immunology, in which he served stints as chair and division head during his time at Berkeley, said David Raulet, director of Berkeley’s Immunotherapeutics and Vaccine Research Initiative (IVRI).

“His actions helped create the superb research environment here, which is so conducive to making the fundamental discoveries that will be the basis of the next generation of medical breakthroughs,” Raulet said.

Self vs. non-self

Allison joined the UC Berkeley faculty as a professor of molecular and cell biology and director of the Cancer Research Laboratory in 1985. An immunologist with a Ph.D. from the University of Texas, Austin, he focused on a type of immune system cell called the T cell or T lymphocyte, which plays a key role in fighting off bacterial and viral infections as well as cancer.

Supercharging the immune system to cure disease: immunotherapy research at UC Berkeley. (UC Berkeley video by Roxanne Makasdjian and Stephen McNally)

At the time, most doctors and scientists believed that the immune system could not be exploited to fight cancer, because cancer cells look too much like the body’s own cells, and any attack against cancer cells would risk killing normal cells and creating serious side effects.

“The community of cancer biologists was not convinced that you could even use the immune system to alter cancer’s outcome, because cancer was too much like self,” said Matthew “Max” Krummel, who was a graduate student and postdoctoral fellow with Allison in the 1990s and is now a professor of pathology and a member of the joint immunology group at UCSF. “The dogma at the time was, ‘Don’t even bother.’ ”

“What was heady about the moment was that we didn’t really listen to the dogma, we just did it,” Krummel added. Allison, in particular, was a bit “irreverent, but in a productive way. He didn’t suffer fools easily.” This attitude rubbed off on the team.

Trying everything they could in mice to tweak the immune system, Krummel and Allison soon found that a protein receptor called CTLA-4 seemed to be holding T cells back, like a brake in a car.

Postdoctoral fellow Dana Leach then stepped in to see if blocking the receptor would unleash the immune system to actually attack a cancerous tumor. In a landmark paper published in Science in 1996, Allison, Leach and Krummel showed not only that antibodies against CTLA-4 released the brake and allowed the immune system to attack the tumors, but that the technique was effective enough to result in long-term disappearance of the tumors.

“When Dana showed me the results, I was really surprised,” Allison said. “It wasn’t that the anti-CTLA-4 antibodies slowed the tumors down. The tumors went away.”

After Allison himself replicated the experiment, “that’s when I said, OK, we’ve got something here.”

Checkpoint blockade

The discovery led to a concept called “checkpoint blockade.” This holds that the immune system has many checkpoints designed to prevent it from attacking the body’s own cells, which can lead to autoimmune disease. As a result, while attempts to rev up the immune system are like stepping on the gas, they won’t be effective unless you also release the brakes.

Allison in 1993

James Allison in 1993, when he was conducting research at UC Berkeley on a promising immunotherapy now reaching fruition. (Jane Scherr photo)

“The temporary activation of the immune system though ‘checkpoint blockade’ provides a window of opportunity during which the immune system is mobilized to attack and eliminate tumors,” Vance said.

Allison spent the next few years amassing data in mice to show that anti-CTLA-4 antibodies work, and then, in collaboration with a biotech firm called Medarex, developed human antibodies that showed promise in early clinical trials against melanoma and other cancers. The therapy was acquired by Bristol-Myers Squibb in 2011 and approved by the FDA as ipilimumab (trade name Yervoy), which is now used to treat skin cancers that have metastasized or that cannot be removed surgically.

Meanwhile, Allison left UC Berkeley in 2004 for Memorial Sloan Kettering research center in New York to be closer to the drug companies shepherding his therapy through clinical trials, and to explore in more detail how checkpoint blockade works.

“Berkeley was my favorite place, and if I could have stayed there, I would have,” he said. “But my research got to the point where all the animal work showed that checkpoint blockade had a lot of potential in people, and working with patients at Berkeley wasn’t possible. There’s no hospital, no patients.”

Thanks to Allison’s doggedness, anti-CTLA-4 therapy is now an accepted therapy for cancer and it opened the floodgates for a slew of new immunotherapies, Krummel said. There now are several hundred ongoing clinical trials involving monoclonal antibodies to one or more receptors that inhibit T cell activity, sometimes combined with lower doses of standard chemotherapy.

Antibodies against one such receptor, PD-1, which Honjo discovered in 1992, have given especially impressive results. Allison’s initial findings can be credited for prompting researchers, including Allison himself, to carry out the studies that have demonstrated the potent anti-cancer effects of PD-1 antibodies. In 2015, the FDA approved anti-PD-1 therapy for malignant melanoma, and has since approved it for non-small-cell lung, gastric and several other cancers.

Science magazine named cancer immunotherapy its breakthrough of 2013 because that year, “clinical trials … cemented its potential in patients and swayed even the skeptics. The field hums with stories of lives extended: the woman with a grapefruit-size tumor in her lung from melanoma, alive and healthy 13 years later; the 6-year-old near death from leukemia, now in third grade and in remission; the man with metastatic kidney cancer whose disease continued fading away even after treatment stopped.”

Allison pursued more clinical trials for immunotherapy at Sloan-Kettering and then in 2012 returned to his native Texas.

Born in Alice, Texas, on Aug. 7, 1948, Allison earned a B.S. in microbiology in 1969 and a Ph.D. in biological science in 1973 from the University of Texas, Austin.

RELATED INFORMATION

SOURCE

http://news.berkeley.edu/2018/10/01/uc-berkeley-research-led-to-nobel-prize-winning-immunotherapy/

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Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

The CRISPR-Cas9 system has proven to be a powerful tool for genome editing allowing for the precise modification of specific DNA sequences within a cell. Many efforts are currently underway to use the CRISPR-Cas9 system for the therapeutic correction of human genetic diseases. CRISPR/Cas9 has revolutionized our ability to engineer genomes and conduct genome-wide screens in human cells.

 

CRISPR–Cas9 induces a p53-mediated DNA damage response and cell cycle arrest in immortalized human retinal pigment epithelial cells, leading to a selection against cells with a functional p53 pathway. Inhibition of p53 prevents the damage response and increases the rate of homologous recombination from a donor template. These results suggest that p53 inhibition may improve the efficiency of genome editing of untransformed cells and that p53 function should be monitored when developing cell-based therapies utilizing CRISPR–Cas9.

 

Whereas some cell types are amenable to genome engineering, genomes of human pluripotent stem cells (hPSCs) have been difficult to engineer, with reduced efficiencies relative to tumour cell lines or mouse embryonic stem cells. Using hPSC lines with stable integration of Cas9 or transient delivery of Cas9-ribonucleoproteins (RNPs), an average insertion or deletion (indel) efficiency greater than 80% was achieved. This high efficiency of insertion or deletion generation revealed that double-strand breaks (DSBs) induced by Cas9 are toxic and kill most hPSCs.

 

The toxic response to DSBs was P53/TP53-dependent, such that the efficiency of precise genome engineering in hPSCs with a wild-type P53 gene was severely reduced. These results indicate that Cas9 toxicity creates an obstacle to the high-throughput use of CRISPR/Cas9 for genome engineering and screening in hPSCs. As hPSCs can acquire P53 mutations, cell replacement therapies using CRISPR/Cas9-enginereed hPSCs should proceed with caution, and such engineered hPSCs should be monitored for P53 function.

 

CRISPR-based editing of T cells to treat cancer, as scientists at the University of Pennsylvania are studying in a clinical trial, should also not have a p53 problem. Nor should any therapy developed with CRISPR base editing, which does not make the double-stranded breaks that trigger p53. But, there are pre-existing humoral and cell-mediated adaptive immune responses to Cas9 in humans, a factor which must be taken into account as the CRISPR-Cas9 system moves forward into clinical trials.

 

References:

 

https://techonomy.com/2018/06/new-cancer-concerns-shake-crispr-prognosis/

 

https://www.statnews.com/2018/06/11/crispr-hurdle-edited-cells-might-cause-cancer/

 

https://www.biorxiv.org/content/early/2017/07/26/168443

 

https://www.nature.com/articles/s41591-018-0049-z.epdf?referrer_access_token=s92jDP_yPBmDmi-USafzK9RgN0jAjWel9jnR3ZoTv0MRjuB3dEnTctGtoy16n3DDbmISsvbln9SCISHVDd73tdQRNS7LB8qBlX1vpbLE0nK_CwKThDGcf344KR6RAm9k3wZiwyu-Kb1f2Dl7pArs5yYSiSLSdgeH7gst7lOBEh9qIc6kDpsytWLHqX_tyggu&tracking_referrer=www.statnews.com

 

https://www.nature.com/articles/s41591-018-0050-6.epdf?referrer_access_token=2KJ0L-tmvjtQdzqlkVXWVNRgN0jAjWel9jnR3ZoTv0Phq6GCpDlJx7lIwhCzBRjHJv0mv4zO0wzJJCeuxJjzoUWLeemH8T4I3i61ftUBkYkETi6qnweELRYMj4v0kLk7naHF-ujuz4WUf75mXsIRJ3HH0kQGq1TNYg7tk3kamoelcgGp4M7UTiTmG8j0oog_&tracking_referrer=www.statnews.com

 

https://www.biorxiv.org/content/early/2018/01/05/243345

 

https://www.nature.com/articles/nmeth.4293.epdf

 

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Image Source:Koch Institute

 

LIVE – OCTOBER 16 – DAY 1- Koch Institute Immune Engineering Symposium 2017, MIT, Kresge Auditorium

Koch Institute Immune Engineering Symposium 2017

http://kochinstituteevents.cvent.com/events/koch-institute-immune-engineering-symposium-2017/agenda-64e5d3f55b964ff2a0643bd320b8e60d.aspx

 

#IESYMPOSIUM

 

Image Source: Leaders in Pharmaceutical Business Intelligence (LPBI) Group

Aviva Lev-Ari, PhD, RN will be in attendance covering the event in REAL TIME

@pharma_BI

@AVIVA1950

#IESYMPOSIUM

@KOCHINSTITUTE

  • The Immune System, Stress Signaling, Infectious Diseases and Therapeutic Implications: VOLUME 2: Infectious Diseases and Therapeutics and VOLUME 3: The Immune System and Therapeutics (Series D: BioMedicine & Immunology) Kindle Edition – on Amazon.com since September 4, 2017

https://www.amazon.com/dp/B075CXHY1B

SYMPOSIUM SCHEDULE

OCTOBER 16 – DAY 1

7:00 – 8:15 Registration

8:15 – 8:30Introductory Remarks
Darrell Irvine | MIT, Koch Institute; HHMI

  • Stimulating the Immune system not only sustaining it for therapies

K. Dane Wittrup | MIT, Koch Institute

8:30 – 9:45Session I
Moderator: Douglas Lauffenburger | MIT, Biological Engineering and Koch Institute

Garry P. Nolan – Stanford University School of Medicine
Pathology from the Molecular Scale on Up

  • Intracellular molecules,
  • how molecules are organized to create tissue
  • Meaning from data Heterogeneity is an illusion: Order in Data ?? Cancer is heterogeneous, Cells in suspension – number of molecules
  • System-wide changes during Immune Response (IR)
  • Untreated, Ineffective therapy, effective therapy
  • Days 3-8 Tumor, Lymph node…
  • Variation is a Feature – not a bug: Effective therapy vs Ineffective – intercellular modules – virtual neighborhoods
  • ordered by connectivity: very high – CD4 T-cells, CD8 T-cels, moderate, not connected
  • Landmark nodes, Increase in responders
  • CODEX: Multiples epitome detection
  • Adaptable to proteins & mRNA
  • Rendering antibody staining via removal to neighborhood mapping
  • Human tonsil – 42 parameters: CD7, CD45, CD86,
  • Automated Annotations of tissues: F, P, V,
  • Normal BALBs
  • Marker expression defined by the niche: B220 vs CD79
  • Marker expression defines the niche
  • Learn neighborhoods and Trees
  • Improving Tissue Classification and staining – Ce3D – Tissue and Immune Cells in 3D
  • Molecular level cancer imaging
  • Proteomic Profiles: multi slice combine
  • Theory is formed to explain 3D nuclear images of cells – Composite Ion Image, DNA replication
  • Replication loci visualization on DNA backbone – nascent transcriptome – bar code of isotopes – 3D  600 slices
  • use CRISPR Cas9 for Epigenetics

Susan Napier Thomas – Georgia Institute of Technology
Transport Barriers in the Tumor Microenvironment: Drug Carrier Design for Therapeutic Delivery to Sentinel Lymph Nodes

  • Lymph Nodes important therapeutics target tissue
  • Lymphatic flow support passive and active antigen transport to lymph nodes
  • clearance of biomolecules and drug formulations: Interstitial transport barriers influence clearance: Arteriole to Venule –
  • Molecular tracers to analyze in vivo clearance mechanisms and vascular transport function
  • quantifying molecular clearance and biodistribution
  • Lymphatic transport increases tracer concentrations within dLN by orders of magnitude
  • Melanoma growth results in remodeled tumor vasculature
  • passive transport via lymphatic to dLN sustained in advanced tumors despite abrogated cell trafficking
  • Engineered biomaterial drug carriers to enhance sentinel lymph node-drug delivery: facilitated by exploiting lymphatic transport
  • TLR9 ligand therapeutic tumor in situ vaccination – Lymphatic-draining CpG-NP enhanced
  • Sturcutral and Cellular barriers: transport of particles is restriced by
  • Current drug delivery technology: lymph-node are undrugable
  • Multistage delivery platform to overcome barriers to lymphatic uptake and LN targeting
  • nano particles – OND – Oxanorbornade OND Time sensitive Linker synthesized large cargo – NP improve payload
  • OND release rate from nanoparticles changes retention in lymph nodes – Axilliary-Brachial delivery
  • Two-stage OND-NP delivery and release system dramatically – OND acumulate in lymphocyte
  •  delivers payload to previously undraggable lymphe tissue
  • improved drug bioactivity  – OND-NP eliminate LN LYMPHOMAS
  • Engineered Biomaterials

Douglas Lauffenburger – MIT, Biological Engineering and Koch Institute
Integrative Multi-Omic Analysis of Tissue Microenvironment in Inflammatory Pathophysiology

  • How to intervene, in predictive manner, in immunesystem-associated complex diseases
  • Understand cell communication beteen immune cells and other cells, i.e., tumor cells
  • Multi-Variate in Vivo – System Approach: Integrative Experiment & COmputational Analysis
  • Cell COmmunication & Signaling in CHronic inflammation – T-cell transfer model for colitis
  • COmparison of diffrential Regulation (Tcell transfer-elicited vs control) anong data types – relying solely on mRNA can be misleading
  • Diparities in differential responses to T cell transfer across data types yield insights concerning broader multi-organ interactions
  • T cell transfer can be ascertained and validated by successful experimental test
  • Cell COmmunication in Tumor MIcro-Environment — integration of single-cell transcriptomic data and protein interaction
  • Standard Cluster Elucidation – Classification of cell population on Full gene expression Profiles using Training sets: Decision Tree for Cell Classification
  • Wuantification of Pairwise Cell-Cell Receptor/Ligand Interactions: Cell type Pairs vs Receptor/Ligand Interaction
  • Pairwise Cell-Cell Receptor/Ligand Interactions
  • Calculate strength of interaction and its statistical significance
  • How the interaction is related to Phenotypic Behaviors – tumor growth rate, MDSC levels,
  • Correlated the Interactions translated to Phynotypic behavior for Therapeutic interventions (AXL via macrophage and fibroblasts)
  • Mouth model translation to Humans – New machine learning approach
  • Pathways, false negative, tumor negative expression
  • Molecular vs Phynotypical expression
  • Categories of inter-species translation
  • Semi-supervised Learning ALgorithms on Transcriptomic Data can ascertain Key Pathways/Processes in Human IBD from mapping mouse IBD

9:45 – 10:15 Break

10:15 – 11:30Session II
Moderator: Tyler Jacks | MIT, Koch Institute; HHMI

Tyler Jacks – MIT, Koch Institute; HHMI
Using Genetically Engineered Mouse Models to Probe Cancer-Immune Interactions

  • Utility of genetically-engineered mouse models of Cancer:
  1. Immune Response (IR),
  2. Tumor0immune microenvironment
  • Lung adenocarcinoma – KRAS mutation: Genetically-engineered model, applications: CRISPR, genetic interactions
  • Minimal Immune response to KP lung tumors: H&E, T cells (CD3), Bcells (B220) for Lenti-x 8 weeks
  • Exosome sequencing : Modeling loss-and gain-of-function mutations in Lung Cancer by CRISPR-Cas9 – germline – tolerance in mice, In vivo CRISPR-induced knockout of Msh2
  • Signatures of MMR deficient
  • Mutation burden and response to Immunotherapy (IT)
  • Programmed neoantigen expression – robust infiltration of T cells (evidence of IR)
  • Immunosuppression – T cell rendered ineffective
  • Lymphoid infiltration: Acute Treg depletion results in T cell infiltration — this depletion causes autoimmune response
  • Lung Treg from KP tumor-bearing mice have a distinct transcriptional heterogeneity through single cell mRNA sequencing
  • KP, FOXP3+, CD4
  • Treg from no existent to existance, Treg cells increase 20 fold =>>>  Treg activation and effectiveness
  • Single cells cluster by tissue and cell type: Treg, CD4+, CD8+, Tetramer-CD4+
  • ILrl1/II-33r unregulated in Treg at late time point
  • Treg-specific deletion of IL-33r results in fewer effector Tregs in Tumor-bearing lungs
  • CD8+ T cell infiltration
  • Tetramer-positive T cells cluster according to time point: All Lung CD8+ T cells
  • IR is not uniform functional differences – Clones show distinct transcriptional profiles
  • Different phynotypes Exhaustive signature
  • CRISPR-mediated modulation of CD8 T cell regulatory genes
  • Genetic dissection of the tumor-immune microenvironment
  • Single cell analysis, CRISPR – CRISPRa,i, – Drug development

Wendell Lim – University of California, San Francisco

Synthetic Immunology: Hacking Immune Cells

  • Precision Cell therapies – engineered by synthetic biology
  • Anti CD19 – drug approved
  • CAR-T cells still face major problems
  1. success limited to B cells cancers = blood vs solid tumors
  2. adverse effects
  3. OFF-TUMOR effects
  • Cell engineering for Cancer Therapy: User remote control (drug) – user control safety
  • Cell Engineering for TX
  1. new sensors – decision making for
  2. tumor recognition – safety,
  3. Cancer is a recognition issue
  • How do we avoid cross-reaction with bystader tissue (OFF TISSUE effect)
  • Tumor recognition: More receptors & integration
  • User Control
  • synthetic NOTCH receptors (different flavors of synNotch) – New Universal platform for cell-to -cell recognition: Target molecule: Extracellular antigen –>> transciptional instruction to cell
  • nextgen T cell: Engineer T cell recognition circuit that integrates multiple inputs: Two receptors – two antigen priming circuit
  • UNARMED: If antigen A THEN receptor A activates CAR
  • “Bystander” cell single antigen vs “tumor” drug antigen
  • Selective clearance of combinatorial tumor – Boulian formulation, canonical response
  • Cell response: Priming –>> Killing: Spatial & Temporal choreographed cell
  • CAR expression while removed from primed cells deminished
  • Solid Tumor: suppress cell microenvironment: Selected response vs non-natural response
  • Immune stimulator IR IL2, IL12, flagellin in the payload — Ourcome: Immune enhancement “vaccination”
  • Immune suppression –  block
  • Envision ideal situation: Unarmed cells
  • FUTURE: identify disease signatures and vulnerabilities – Precision Medicine using Synthetic Biology

Darrell Irvine – MIT, Koch Institute; HHMI
Engineering Enhanced Cancer Vaccines to Drive Combination Immunotherapies

  • Vaccine to drive IT
  • Intervening in the cancer-immunity cycle – Peptide Vaccines
  • poor physiology  of solute transport to tissue
  • endogenous albumin affinity – Lymphe Node dying
  • Designing Albumin-hitchhiking vaccines
  • Amphiphile-vaccine enhance uptake in lymph nodes in small and large animal models
  • soluble vaccine vs Amphiphile-vaccine
  • DIRECTING Vaccines to the Lymph nodes
  • amph-peptide antigen: Prime, booster, tetramer
  • albimin-mediated LN-targeting of both antigen and adjuvant maximizes IR
  • Immuno-supressed microenvironment will not be overcome by vaccines
  • Replacing adoptive T cell transfer with potent vaccine
  • exploiting albumin biology for mucosal vaccine delivery by amph-vaccines
  • Amph-peptides and -adjuvants show enhanced uptake/retention in lung tissue
  •  Enhancing adoptive T cell therapy: loss of T cell functionality, expand in vivo
  • boost in vivo enhanced adoptive T cell therapy
  • CAR-T cells: Enable T cells to target any cell surface protein
  • “Adaptor”-targeting CAR-T cells to deal with tumor cell heterogeneity
  • Lymph node-targeting Amph as CAR T booster vaccine: prining, production of cytokines
  • Boosting CAR T with amph-caccines: anti FITC CAR-T by DSPE=PEG-FITC coated
  • Targeting FITC to lymph node antigen presenting cells
  • Modulatory Macrophages
  • Amph-FITC expands FITC-CAR T cells in vivo – Adjuvant is needed
  • Hijacking albumin’s natural trafficking pathway

11:30 – 1:00  Lunch Break

1:00 – 2:15Session III
Moderator: Darrell Irvine | MIT, Koch Institute; HHMI

Nicholas P. Restifo – National Cancer Institute
Extracellular Potassium Regulates Epigenetics and Efficacy of Anti-Tumor T Cells

Why T cell do not kill Cancer cells?

  • co-inhibition
  • hostile tumor microenvironment

CAR T – does not treat solid tumors

Somatic mutation

  1. resistence of T cell based IT due to loss of function mutations
  2. Can other genes be lost?

CRISPR Cas9 – used to identify agents – GeCKOv2 Human library

Two cell-type (2CT) CRISPR assay system for genome-wide mutagenesis

  • work flow for genome-scale SRISPR mutagenesis profiling of genes essential for T cell mediate cytosis
  • sgRNA enrichment at the individual gene level by multiple methods:
  1. subunits of the MHC Class I complex
  2. CRISPR mutagenesis cut germline
  • Measutring the generalizability of resistance mechanism and mice in vivo validation
  • Validation of top gene candidates using libraries: MART-1
  • Checkpoint blockade: cells LOF causes tumor growth and immune escape
  • Weird genesL Large Ribisomal Subunit Proteins are nor all essential for cell survival
  • Bias in enrichment of 60S vs 40S
  • Novel elements of MHC class I antigen processing and presentation
  • Association of top CRISPR hits with response rates to IT – antiCTLA-4
  • CRISPR help identify novel regulators of T cells
  • Analyzed sgRNA – second rarest sgRNA for gene BIRC2 – encoded the Baculoviral Inhibitor
  • Drugs that inhibit BIRC2
  • How T cells can kill tumor cells more efficiently
  • p38kiaseas target for adoptive immunotherapy
  • FACS-based – Mapk14
  • Potent targets p38 – Blockade PD-1 or p38 ??
  • p38 signaling: Inhibition augments expansion and memory-marked human PBMC and TIL cells, N. P. Restifo
  • Tumor killing capacity of human CD19-specific, gene engineered T cells

Jennifer Elisseeff – Johns Hopkins University
The Adaptive Immune Response to Biomaterials and Tissue Repair

  • design scafolds, tissue-specific microenvironment
  • clinical translation of biosynthetic implants for soft tissue reconstruction
  • Local environment affects biomaterials: Epidermis, dermis
  • CD4+ T cells
  • Immune system – first reponders to materials: Natural or Synthetic
  • Biological (ECM) scaffolds to repair muscle injury
  • Which immune cells enter the WOUND?
  • ECM alters Macrophages: CD86, CD206
  • Adaptive system impact on Macrophages: CD86
  • mTOR signaling pathway M2 depend on Th2 Cells in regeneration of cell healing of surgical wounds
  • Systemic Immunological changes
  • Is the response antigen specific? – IL-4 expression in ILN,
  • Tissue reconstruction Clinical Trial: FDA ask to look at what cells infiltrate the scaffold
  • Trauma/biomaterial response – Injury induction of Senescence, anti apoptosis
  • Injury to skin or muscle
  • Is pro-regenerative environment (Th2/M2) pro-tumorigenic?
  • SYNTHETIC Materials for scafolds
  • Biomaterials and Immunology
  1. Immune response to bioscafolds
  2. environment modulate the immune system
  • Regenerative Immunetherapy

Marcela Maus – Massachusetts General Hospital

Engineering Better T Cells

  • Comparing CD19 CARs for Leukemia – anti-CD19- directed CAR T cells with r/r B-cell ALL – age 3-25 – FDA approved Novartis tisagenlecleucel – for pediatric r/r/ ALL
  • Phase II in diffuse large B cell lymphoma. Using T cells – increases prospects for cure
  • Vector retroviral – 30 day expression
  • measuring cytokines release syndrome: Common toxicity with CAR 19
  • neurological toxicity, B-cell aplagia
  • CART issues with heme malignancies
  1. decrease cytokine release
  2. avoid neurological toxicity – homing
  3. new targets address antigene escape variants – Resistance, CD19 is shaded, another target needed
  4. B Cell Maturation Antigen (BCMA) Target
  5. Bluebird Bio: Response duratio up to 54 weeks – Active dose cohort
  6. natural ligand CAR based on April
  7. activated in response to TACI+ target cells – APRIL-based CARs but not BCMA-CAR is able to kill TACI+ target cells
  • Hurdles for Solid Tumors
  1. Specific antigen targets
  2. tumor heterogeneity
  3. inhibitory microenvironment
  • CART in Glioblastoma
  1. rationale for EGFRvIII as therapeutic target
  2. Preclinical Studies & Phase 1: CAR t engraft, not as highly as CD19
  3. Upregulation of immunosuppression and Treg infiltrate in CART EGFRvIII as therapeutic target, Marcela Maus
  • What to do differently?

 

2:15 – 2:45 Break

2:45 – 4:00 Session IV
Moderator: Arup K. Chakraborty | MIT, IMES

Laura Walker – Adimab, LLC
Molecular Dissection of the Human Antibody Response to Respiratory Syncytial Virus

  • prophylactic antibody is available
  • Barriers for development of Vaccine
  • Prefusion and Postfusion RSV structures
  • Six major antigenic sites on RSV F
  • Blood samples Infants less 6 month of age and over 6 month: High abundance RSV F -specific memory B Cells are group  less 6 month

Arup K. Chakraborty – MIT, Institute for Medical Engineering & Science
How to Hit HIV Where it Hurts

  • antibody  – Model IN SILICO
  • Check affinity of each Ab for the Seaman panel of strain
  • Breadth of coverage
  • immmunize with cocktail of variant antigens
  • Mutations on Affinity Maturation: Molecular dynamics
  • bnAb eveolution: Hypothesis – mutations evolution make the antigen binding region more flexible,
  • Tested hypothesisi: carrying out affinity maturation – LOW GERMLINE AFFINITY TO CONSERVE RESIDUES IN 10,000 trials, acquire the mutation (generation 300)

William Schief – The Scripps Research Institute
HIV Vaccine Design Targeting the Human Naive B Cell Repertoire

  • HIV Envelope Trimer Glycan): the Target of neutralizing Antibodies (bnAbs)
  • Proof of principle for germline-targeting: VRC)!-class bnAbs
  • design of a nanoparticle
  • can germline -targeting innumogens prime low frequency precursors?
  • Day 14 day 42 vaccinate
  • Precursor frequency and affinity are limiting for germline center (GC) entry at day 8
  • Germline-targeting immunogens can elicit robust, high quality SHM under physiological conditions of precursor frequency and affinity at day 8, 16, 36
  • Germline-targeting immunogens can lead to production of memory B cells

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Targeting Cancer Neoantigens and Metabolic Change in T-cells

Curator: Larry H. Bernstein, MD, FCAP

Targeting Cancer Neoantigens

WordCloud created by Noam Steiner Tomer 8/10/2020

Updated 5/28/2016

Updated 6/1/2016

Updated 6/11/2021

Fighting Cancer with Borrowed Immunity

http://www.genengnews.com/gen-news-highlights/fighting-cancer-with-borrowed-immunity/81252754/

Outsource a part of the T cell’s immune value chain, propose cancer immunotherapy researchers, from patient T cells to donor T cells. The novel allogeneic approach could rely on T-cell receptor gene transfer to generate broad and tumor-specific T-cell immune responses. [NIAID]

A new cancer immunotherapy approach could essentially outsource a crucial T-cell function. This function, T-cell reactivity to specific cancer antigens, is sometimes lacking in cancer patients. Yet, according to a new proof-of-principle study, these patients could benefit from T cells provided by healthy donors. Specifically, the healthy donors’ T cells could be used to broaden the T-cell receptor repertoires of the cancer patients’ T cells.

Ultimately, this approach relies on a cancer immunotherapy technique called T-cell receptor (TCR) transfer, or the genetic transfer of TCR chains. TCR transfer can be used to outsource the T cell’s learning function, the process by which a T cell acquires the ability to recognize foreign antigens—in this case, the sort of proteins that can be expressed on the surface of cancer cells. Because cancer cells harbor faulty proteins, they can also display foreign protein fragments, also known as neoantigens, on their surface, much in the way virus-infected cells express fragments of viral proteins.

The approach was detailed in a paper that appeared May 19 in the journal Science, in an article entitled, “Targeting of Cancer Neoantigens with Donor-Derived T Cell Receptor Repertoires.” This article, by scientists based at the Netherlands Cancer Institute and the University of Oslo, describes a novel strategy to broaden neoantigen-specific T-cell responses. Such a strategy would be useful in overcoming a common limitation seen in the immune response to cancer: Neoantigen-specific T-cell reactivity is generally limited to just a few mutant epitopes, even though the number of predicted epitopes is large.

“We demonstrate that T cell repertoires from healthy donors provide a rich source of T cells that specifically recognize neoantigens present on human tumors,” the study’s authors wrote. “Responses to 11 epitopes were observed, and for the majority of evaluated epitopes, potent and specific recognition of tumor cells endogenously presenting the neoantigens was detected.”

First, the researchers mapped all possible neoantigens on the surface of melanoma cells from three different patients. In all three patients, the cancer cells seemed to display a large number of different neoantigens. But when the researchers tried to match these to the T cells derived from within the patient’s tumors, most of these aberrant protein fragments on the tumor cells went unnoticed.

Next, the researchers tested whether the same neoantigens could be seen by T cells derived from healthy volunteers. Strikingly, these donor-derived T cells could detect a significant number of neoantigens that had not been seen by the patients’ T cells.

“Many of the T cell reactivities [among donor T cells] involved epitopes that in vivo were neglected by patient autologous tumor-infiltrating lymphocytes,” the authors of the Science article continued. “T cells re-directed with T cell receptors identified from donor-derived T cells efficiently recognized patient-derived melanoma cells harboring the relevant mutations, providing a rationale for the use of such ‘outsourced’ immune responses in cancer immunotherapy.”

“In a way, our findings show that the immune response in cancer patients can be strengthened; there is more on the cancer cells that makes them foreign that we can exploit. One way we consider doing this is finding the right donor T cells to match these neoantigens,” said Ton Schumacher, Ph.D., a principal investigator at the Netherlands Cancer Institute. “The receptor that is used by these donor T cells can then be used to genetically modify the patient’s own T cells so these will be able to detect the cancer cells.”

“Our study shows that the principle of outsourcing cancer immunity to a donor is sound,” added Johanna Olweus, M.D., Ph.D., who heads a research group at the University of Oslo. “However, more work needs to be done before patients can benefit from this discovery. Thus, we need to find ways to enhance the throughput.”

“We are currently exploring high-throughput methods to identify the neoantigens that the T cells can ‘see’ on the cancer and isolate the responding cells. But the results showing that we can obtain cancer-specific immunity from the blood of healthy individuals are already very promising.”

Targeting of cancer neoantigens with donor-derived T cell receptor repertoires

Erlend Strønen1,2Mireille Toebes3Sander Kelderman3,…., Fridtjof Lund-Johansen2,5Johanna Olweus1,2,*,Ton N. Schumacher3,*,   + Author Affiliations
Science  19 May 2016:                         http://dx.doi.org:/10.1126/science.aaf2288

Accumulating evidence suggests that clinically efficacious cancer immunotherapies are driven by T cell reactivity against DNA mutation-derived neoantigens. However, among the large number of predicted neoantigens, only a minority is recognized by autologous patient T cells, and strategies to broaden neoantigen specific T cell responses are therefore attractive. Here, we demonstrate that naïve T cell repertoires of healthy blood donors provide a source of neoantigen-specific T cells, responding to 11/57 predicted HLA-A2-binding epitopes from three patients. Many of the T cell reactivities involved epitopes that in vivo were neglected by patient autologous tumor-infiltrating lymphocytes. Finally, T cells re-directed with T cell receptors identified from donor-derived T cells efficiently recognized patient-derived melanoma cells harboring the relevant mutations, providing a rationale for the use of such “outsourced” immune responses in cancer immunotherapy.
 

Metabolic maintenance of cell asymmetry following division in activated T lymphocytes.

Verbist KC1, Guy CS1, Milasta S1, Liedmann S1, Kamiński MM1, Wang R2, Green DR1
Nature. 2016 Apr 21; 532(7599):389-93.   http://dx. doi.org:/10.1038/nature17442. Epub 2016 Apr 11

Asymmetric cell division, the partitioning of cellular components in response to polarizing cues during mitosis, has roles in differentiation and development. It is important for the self-renewal of fertilized zygotes in Caenorhabditis elegans and neuroblasts in Drosophila, and in the development of mammalian nervous and digestive systems. T lymphocytes, upon activation by antigen-presenting cells (APCs), can undergo asymmetric cell division, wherein the daughter cell proximal to the APC is more likely to differentiate into an effector-like T cell and the distal daughter is more likely to differentiate into a memory-like T cell. Upon activation and before cell division, expression of the transcription factor c-Myc drives metabolic reprogramming, necessary for the subsequent proliferative burst. Here we find that during the first division of an activated T cell in mice, c-Myc can sort asymmetrically. Asymmetric distribution of amino acid transporters, amino acid content, and activity of mammalian target of rapamycin complex 1 (mTORC1) is correlated with c-Myc expression, and both amino acids and mTORC1 activity sustain the differences in c-Myc expression in one daughter cell compared to the other. Asymmetric c-Myc levels in daughter T cells affect proliferation, metabolism, and differentiation, and these effects are altered by experimental manipulation of mTORC1 activity or c-Myc expression. Therefore, metabolic signalling pathways cooperate with transcription programs to maintain differential cell fates following asymmetric T-cell division.

AMPK Is Essential to Balance Glycolysis and Mitochondrial Metabolism to Control T-ALL Cell Stress and Survival.

 
T cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy associated with Notch pathway mutations. While both normal activated and leukemic T cells can utilize aerobic glycolysis to support proliferation, it is unclear to what extent these cell populations are metabolically similar and if differences reveal T-ALL vulnerabilities. Here we show that aerobic glycolysis is surprisingly less active in T-ALL cells than proliferating normal T cells and that T-ALL cells are metabolically distinct. Oncogenic Notch promoted glycolysis but also induced metabolic stress that activated 5′ AMP-activated kinase (AMPK). Unlike stimulated T cells, AMPK actively restrained aerobic glycolysis in T-ALL cells through inhibition of mTORC1 while promoting oxidative metabolism and mitochondrial Complex I activity. Importantly, AMPK deficiency or inhibition of Complex I led to T-ALL cell death and reduced disease burden. Thus, AMPK simultaneously inhibits anabolic growth signaling and is essential to promote mitochondrial pathways that mitigate metabolic stress and apoptosis in T-ALL.
 
 

Glutamine Modulates Macrophage Lipotoxicity.

He L1,2, Weber KJ3,4, Schilling JD5,6,7
Nutrients. 2016 Apr 12;8(4). pii: E215.   http://dx.doi.org:/10.3390/nu8040215
 
Obesity and diabetes are associated with excessive inflammation and impaired wound healing. Increasing evidence suggests that macrophage dysfunction is responsible for these inflammatory defects. In the setting of excess nutrients, particularly dietary saturated fatty acids (SFAs), activated macrophages develop lysosome dysfunction, which triggers activation of the NLRP3 inflammasome and cell death. The molecular pathways that connect lipid stress to lysosome pathology are not well understood, but may represent a viable target for therapy. Glutamine uptake is increased in activated macrophages leading us to hypothesize that in the context of excess lipids glutamine metabolism could overwhelm the mitochondria and promote the accumulation of toxic metabolites. To investigate this question we assessed macrophage lipotoxicity in the absence of glutamine using LPS-activated peritoneal macrophages exposed to the SFA palmitate. We found that glutamine deficiency reduced lipid induced lysosome dysfunction, inflammasome activation, and cell death. Under glutamine deficient conditions mTOR activation was decreased and autophagy was enhanced; however, autophagy was dispensable for the rescue phenotype. Rather, glutamine deficiency prevented the suppressive effect of the SFA palmitate on mitochondrial respiration and this phenotype was associated with protection from macrophage cell death. Together, these findings reveal that crosstalk between activation-induced metabolic reprogramming and the nutrient microenvironment can dramatically alter macrophage responses to inflammatory stimuli.
 
 

Immunoregulatory Protein B7-H3 Reprograms Glucose Metabolism in Cancer Cells by ROS-Mediated Stabilization of HIF1α

Sangbin Lim1Hao Liu1,2,*Luciana Madeira da Silva1Ritu Arora1,…., Gary A. Piazza1Oystein Fodstad1,4,*, and Ming Tan1,5,*
C
ancer Res April 5, 2016    http://dx.doi.org:/10.1158/0008-5472.CAN-15-1538

B7-H3 is a member of B7 family of immunoregulatory transmembrane glycoproteins expressed by T cells. While B7-H3 overexpression is associated with poor outcomes in multiple cancers, it also has immune-independent roles outside T cells and its precise mechanistic contributions to cancer are unclear. In this study, we investigated the role of B7-H3 in metabolic reprogramming of cancer cells in vitro and in vivo. We found that B7-H3 promoted the Warburg effect, evidenced by increased glucose uptake and lactate production in B7-H3–expressing cells. B7-H3 also increased the protein levels of HIF1α and its downstream targets, LDHA and PDK1, key enzymes in the glycolytic pathway. Furthermore, B7-H3 promoted reactive oxygen species–dependent stabilization of HIF1α by suppressing the activity of the stress-activated transcription factor Nrf2 and its target genes, including the antioxidants SOD1, SOD2, and PRX3. Metabolic imaging of human breast cancer xenografts in mice confirmed that B7-H3 enhanced tumor glucose uptake and tumor growth. Together, our results illuminate the critical immune-independent contributions of B7-H3 to cancer metabolism, presenting a radically new perspective on B7 family immunoregulatory proteins in malignant progression. Cancer Res; 76(8); 1–12. ©2016 AACR.

TLR-Mediated Innate Production of IFN-γ by CD8+ T Cells Is Independent of Glycolysis.

Salerno F1, Guislain A2, …, Wolkers MC2.
J Immunol. 2016 May 1;196(9):3695-705.   http://dx.doi.org:/10.4049/jimmunol.1501997. Epub 2016 Mar 25.
 
CD8(+) T cells can respond to unrelated infections in an Ag-independent manner. This rapid innate-like immune response allows Ag-experienced T cells to alert other immune cell types to pathogenic intruders. In this study, we show that murine CD8(+) T cells can sense TLR2 and TLR7 ligands, resulting in rapid production of IFN-γ but not of TNF-α and IL-2. Importantly, Ag-experienced T cells activated by TLR ligands produce sufficient IFN-γ to augment the activation of macrophages. In contrast to Ag-specific reactivation, TLR-dependent production of IFN-γ by CD8(+) T cells relies exclusively on newly synthesized transcripts without inducing mRNA stability. Furthermore, transcription of IFN-γ upon TLR triggering depends on the activation of PI3K and serine-threonine kinase Akt, and protein synthesis relies on the activation of the mechanistic target of rapamycin. We next investigated which energy source drives the TLR-induced production of IFN-γ. Although Ag-specific cytokine production requires a glycolytic switch for optimal cytokine release, glucose availability does not alter the rate of IFN-γ production upon TLR-mediated activation. Rather, mitochondrial respiration provides sufficient energy for TLR-induced IFN-γ production. To our knowledge, this is the first report describing that TLR-mediated bystander activation elicits a helper phenotype of CD8(+) T cells. It induces a short boost of IFN-γ production that leads to a significant but limited activation of Ag-experienced CD8(+) T cells. This activation suffices to prime macrophages but keeps T cell responses limited to unrelated infections.
 
 
 
 Immunometabolism of regulatory T cells 

Newton RPriyadharshini B & Laurence A Turk
Nature Immunology 2016;17:618–625
  http://dx.doi.
doi.org:/10.1038/ni.3466

The bidirectional interaction between the immune system and whole-body metabolism has been well recognized for many years. Via effects on adipocytes and hepatocytes, immune cells can modulate whole-body metabolism (in metabolic syndromes such as type 2 diabetes and obesity) and, reciprocally, host nutrition and commensal-microbiota-derived metabolites modulate immunological homeostasis. Studies demonstrating the metabolic similarities of proliferating immune cells and cancer cells have helped give birth to the new field of immunometabolism, which focuses on how the cell-intrinsic metabolic properties of lymphocytes and macrophages can themselves dictate the fate and function of the cells and eventually shape an immune response. We focus on this aspect here, particularly as it relates to regulatory T cells.

Figure 1: Proposed model for the metabolic signatures of various Treg cell subsets.

Proposed model for the metabolic signatures of various Treg cell subsets.

http://www.nature.com/ni/journal/v17/n6/carousel/ni.3466-F1.jpg

(a) Activated CD4+ T cells that differentiate into the Teff cell lineage (green) (TH1 or TH17 cells) are dependent mainly on carbon substrates such as glucose and glutamine for their anabolic metabolism. In contrast to that, pTreg cells…
 
 
 
T-bet is a key modulator of IL-23-driven pathogenic CD4+ T cell responses in the intestine
 
Krausgruber TSchiering CAdelmann K & Harrison OJ.
Nature Communications 7; Article number:11627    http://dx.doi.org:/10.1038/ncomms11627

IL-23 is a key driver of pathogenic Th17 cell responses. It has been suggested that the transcription factor T-bet is required to facilitate IL-23-driven pathogenic effector functions; however, the precise role of T-bet in intestinal T cell responses remains elusive. Here, we show that T-bet expression by T cells is not required for the induction of colitis or the differentiation of pathogenic Th17 cells but modifies qualitative features of the IL-23-driven colitogenic response by negatively regulating IL-23R expression. Consequently, absence of T-bet leads to unrestrained Th17 cell differentiation and activation characterized by high amounts of IL-17A and IL-22. The combined increase in IL-17A/IL-22 results in enhanced epithelial cell activation and inhibition of either IL-17A or IL-22 leads to disease amelioration. Our study identifies T-bet as a key modulator of IL-23-driven colitogenic responses in the intestine and has important implications for understanding of heterogeneity among inflammatory bowel disease patients.
 

Th17 cells are enriched at mucosal sites, produce high amounts of IL-17A, IL-17F and IL-22, and have an essential role in mediating host protective immunity against a variety of extracellular pathogens1. However, on the dark side, Th17 cells have also been implicated in a variety of autoimmune and chronic inflammatory conditions, including inflammatory bowel disease (IBD)2. Despite intense interest, the cellular and molecular cues that drive Th17 cells into a pathogenic state in distinct tissue settings remain poorly defined.

The Th17 cell programme is driven by the transcription factor retinoid-related orphan receptor gamma-t (RORγt) (ref. 3), which is also required for the induction and maintenance of the receptor for IL-23 (refs 4, 5). The pro-inflammatory cytokine IL-23, composed of IL-23p19 and IL-12p40 (ref. 6), has been shown to be a key driver of pathology in various murine models of autoimmune and chronic inflammatory disease such as experimental autoimmune encephalomyelitis (EAE)7, collagen induced arthritis8 and intestinal inflammation9, 10, 11, 12. Several lines of evidence, predominantly derived from EAE, suggest that IL-23 promotes the transition of Th17 cells to pathogenic effector cells9, 10, 11, 12. Elegant fate mapping experiments of IL-17A-producing cells during EAE have shown that the majority of IL-17A+IFN-γ+ and IL-17A−IFN-γ+ effector cells arise from Th17 cell progeny13. This transition of Th17 cells into IFN-γ-producing ‘ex’ Th17 cells required IL-23 and correlated with increased expression of T-bet. The T-box transcription factor T-bet drives the Th1 cell differentiation programme14 and directly transactivates the Ifng gene by binding to its promoter as well as multiple enhancer elements15. Indeed, epigenetic analyses have revealed that the loci for T-bet and IFN-γ are associated with permissive histone modifications in Th17 cells suggesting that Th17 cells are poised to express T-bet which could subsequently drive IFN-γ production16, 17.

A similar picture is emerging in the intestine where IL-23 drives T-cell-mediated intestinal pathology which is thought to be dependent on expression of T-bet18 and RORγt (ref. 19) by T cells. In support of this we have recently shown that IL-23 signalling in T cells drives the emergence of IFN-γ producing Th17 cells in the intestine during chronic inflammation20. Collectively these studies suggest a model whereby RORγt drives differentiation of Th17 cells expressing high amounts of IL-23R, and subsequently, induction of T-bet downstream of IL-23 signalling generates IL-17A+IFN-γ+ T cells that are highly pathogenic. Indeed, acquisition of IFN-γ production by Th17 cells has been linked to their pathogenicity in several models of chronic disease13, 21, 22, 23, 24 and a population of T cells capable of producing both IL-17A and IFN-γ has also been described in intestinal biopsies of IBD patients25, 26.

However, in the context of intestinal inflammation, it remains poorly defined whether the requirement for RORγt and T-bet reflects a contribution of Th17 and Th1 cells to disease progression or whether Th17 cells require T-bet co-expression to exert their pathogenic effector functions. Here, we use two distinct models of chronic intestinal inflammation and make the unexpected finding that T-bet is dispensable for IL-23-driven colitis. Rather the presence of T-bet serves to modify the colitogenic response restraining IL-17 and IL-22 driven pathology. These data identify T-bet as a key modulator of IL–23-driven colitogenic effector responses in the intestine and have important implications for understanding of heterogeneous immune pathogenic mechanisms in IBD patients.

 
Figure 1: IL-23 signalling is required for bacteria-driven T-cell-dependent colitis and the emergence of IL-17A+IFN-γ+ T cells.
C57BL/6 WT and Il23r−/− mice were infected orally with Hh and received weekly i.p. injections of IL-10R blocking antibody. Mice were killed at 4 weeks post infection and assessed for intestinal inflammation. (a) Colitis scores. (b) Typhlitis sores. (c) Representative photomicrographs of colon and caecum (× 10 magnification; scale bars, 200μM). (d) Representative flow cytometry plots of colonic lamina propria gated on viable CD4+ T cells. (e) Frequencies of IL-17A+ and/or IFN-γ+ CD4+ T cells present in the colon. Data represent pooled results from two independent experiments (n=12 for WT, n=10 for Il23r−/−). Bars are the mean and each symbol represents an individual mouse. *P<0.05, ***P<0.001 as calculated by Mann–Whitney U test.
 

IL-23 signals are dispensable for T-bet and RORγt expression 

RORγt but not T-bet is required for T cell transfer colitis

Figure 2: RORγt but not T-bet expression by CD4+ T cells is required for the development of T cell transfer colitis.

http://www.nature.com/ncomms/2016/160519/ncomms11627/images_article/ncomms11627-f2.jpg

C57BL/6 Rag1−/− mice were injected i.p. with 4 × 105 CD4+CD25CD45RBhi T cells from C57BL/6 WT,Rorc−/− or Tbx21−/− donors. Mice were killed when recipients of Tbx21−/− T cells developed clinical signs of disease (4–6 weeks) and assessed for intestinal inflammation. (a) Colitis scores. (b) Representative photomicrographs of proximal colon sections (× 10 magnification; scale bars, 200μM). (c) Concentration of cytokines released from colon explants into the medium after overnight culture. Data represent pooled results from two independent experiments (n=14 for WT, n=11 for Rorc−/−, n=14 forTbx21−/−). Bars are the mean and each symbol represents an individual mouse. Bars are the mean and error bars represent s.e.m. *P<0.05, **P<0.01, ***P<0.001 as calculated by Kruskal–Wallis one-way ANOVA with Dunn’s post-test.

T-bet is dispensable for IL-17A+IFN-γ+ intestinal T cells

Figure 3: T-bet expression by CD4+ T cells is not required for the emergence of IL-17A+IFN-γ+ T cells.

http://www.nature.com/ncomms/2016/160519/ncomms11627/images_article/ncomms11627-f3.jpg

C57BL/6 Rag1−/− mice were injected i.p. with 4×105 CD4+CD25CD45RBhi T cells from C57BL/6 WT,Rorc−/− or Tbx21−/− donors. Mice were killed when recipients of Tbx21−/−T cells developed clinical signs of disease (4–6 weeks). (a) Representative plots of IL-17A and IFN-γ expression in colonic CD4+ T cells. (b) Frequencies of IL-17A+ and/or IFN-γ+ cells among colonic CD4+ T cells. (c) Total numbers of IL-17A+and/or IFN-γ+ CD4+ T cells present in the colon. Data represent pooled results from three independent experiments (n=20 for WT, n=18 for Tbx21−/−, n=12 for Rorc−/−). Bars are the mean and each symbol represents an individual mouse. *P<0.05, **P<0.01, ***P<0.001 as calculated by Kruskal–Wallis one-way ANOVA with Dunn’s post-test.

T-bet deficiency promotes an exacerbated Th17-type response

Our transfer of Tbx21−/− T cells revealed a striking increase in the frequency of IL-17A+IFN-γcells (Fig. 3) and we reasoned that T-bet-deficiency could impact on Th17 cell cytokine production. Therefore, we transferred WT or Tbx21−/− CD4+ T cells into Rag1−/− recipients and measured the expression of RORγt, IL-17A, IL-17F and IL-22 by CD4+ T cells isolated from the colon. In agreement with our earlier findings, Tbx21−/− T cells gave rise to significantly increased frequencies of RORγt-expressing T cells capable of producing IL-17A (Fig. 4a). Furthermore, T-bet deficiency also led to a dramatic expansion of IL-17F and IL-22-expressing cells, which constituted only a minor fraction in WT T cells (Fig. 4a,b). By contrast, the frequency of granulocyte-macrophage colony-stimulating factor (GM-CSF) and IFN-γ producing cells was significantly reduced in T-bet-deficient T cells as compared with WT T cells. When analysed in more detail we noted that the production of IL-17A, IL-17F and IL-22 increased specifically in T-bet-deficient IL-17A+IFN-γ+ T cells as compared with WT T cells whereas IFN-γ production decreased overall in the absence of T-bet as expected (Supplementary Fig. 4A). Similarly, GM-CSF production was also generally reduced in Tbx21−/− CD4+ T cells further suggesting a shift in the qualitative nature of the T cell response.

Figure 4: T-bet-deficient CD4+ T cells promote an exacerbated Th17-type inflammatory response.

http://www.nature.com/ncomms/2016/160519/ncomms11627/images_article/ncomms11627-f4.jpg

C57BL/6 Rag1−/− mice were injected i.p. with 4×105 CD4+CD25CD45RBhi T cells from C57BL/6 WT orTbx21−/− donors. Mice were killed when recipients of Tbx21−/−T cells developed clinical signs of disease (4–6 weeks). (a) Representative plots of cytokines and transcription factors in WT or Tbx21−/− colonic CD4+ T cells. (b) Frequency of IL-17A+, IL-17F+, IL-22+, GM-CSF+ or IFN-γ+ colonic T cells in WT orTbx21−/−. (c) quantitative reverse transcription PCR (qRT-PCR) analysis of mRNA levels of indicated genes in colon tissue homogenates. (d) Total number of neutrophils (CD11b+ Gr1high) in the colon. (e) Primary epithelial cells were isolated from the colon of steady state C57BL/6 Rag1−/− mice and stimulated with 10ngml−1 cytokines for 4h after which cells were harvested and analysed by qRT-PCR for the indicated genes. Data in bd represent pooled results from two independent experiments (n=14 for WT, n=11 for Tbx21−/−). Bars are the mean and error bars represent s.e.m. Data in e are pooled results from four independent experiments, bars are the mean and error bars represent s.e.m. *P<0.05, **P<0.01,***P<0.001 as calculated by Mann–Whitney U test.

………

T-bet-deficient colitis depends on IL-23, IL-17A and IL-22

In the present study we show that bacteria-driven colitis is associated with the IL-23-dependent emergence of IFN-γ-producing Th17 cells co-expressing RORγt and T-bet. Strikingly, while RORγt is required for the differentiation of IFN-γ-producing Th17 cells and induction of colitis, T-bet is dispensable for the emergence of IL-17A+IFN-γ+ T cells and intestinal pathology. Our results show that instead of a mandatory role in the colitogenic response, the presence of T-bet modulates the qualitative nature of the IL-23-driven intestinal inflammatory response. In the presence of T-bet, IL-23-driven colitis is multifunctional in nature and not functionally dependent on either IL-17A or IL-22. By contrast, in the absence of T-bet a highly polarized colitogenic Th17 cell response ensues which is functionally dependent on both IL-17A and IL-22. T-bet-deficient T cells are hyper-responsive to IL-23 resulting in enhanced STAT3 activation and downstream cytokine secretion providing a mechanistic basis for the functional changes. These data newly identify T-bet as a key modulator of IL-23-driven colitogenic CD4+ T cell responses.

Contrary to our expectations T-bet expression by CD4 T cells was not required for their pathogenicity. In keeping with the negative effect of T-bet on Th17 differentiation40, 41, 42, we observed highly polarized Th17 responses in T-bet-deficient intestinal T cells. Early studies demonstrated that IFN-γ could suppress the differentiation of Th17 cells40 and thus the reduced IFN-γ production by Tbx21−/−T cells could facilitate Th17 cell generation. However, our co-transfer studies revealed unrestrained Th17 differentiation of Tbx21−/− T cells even in the presence of WT T cells, suggesting a cell autonomous role for T-bet-mediated suppression of the Th17 programme. Indeed, the role of T-bet as a transcriptional repressor of the Th17 cell fate has been described recently. For example, T-bet physically interacts with and sequesters Runx1, thereby preventing Runx1-mediated induction of RORγt and Th17 cell differentiation43. In addition, T-bet binds directly to and negatively regulates expression of many Th17-related genes15, 34 and we identified IL23r to be repressed in a T-bet-dependent manner. In line with this we show here that T-bet-deficient intestinal T cells express higher amounts of Il23r as well as Rorc. This resulted in enhanced IL-23-mediated STAT3 activation and increased production of IL-17A and IL-22. It has also been suggested that T-bet activation downstream of IL-23R signalling is required for pathogenic IL-23-driven T cell responses43, 44. However, we did not find a role for IL-23 in the induction and/or maintenance of T-bet expression and colitis induced by T-bet-deficient T cells was IL-23 dependent. Collectively, these findings demonstrate that T-bet deficiency leads to unrestrained expansion of colitogenic Th17 cells, which is likely mediated through enhanced activation of the IL-23R-STAT3 pathway.

The observation that T-bet-deficient T cells retain their colitogenic potential is in stark contrast to earlier studies. Neurath et al.18 convincingly showed that adoptive transfer of Tbx21−/− CD4+ T cells into severe combined immunodeficiency (SCID) recipients failed to induce colitis and this correlated with reduced IFN-γ and increased IL-4 production. Another study revealed that IL-4 plays a functional role in inhibiting the colitogenic potential of Tbx21−/− T cells, as recipients ofStat6−/−Tbx21−/− T cells developed severe colitis37. Importantly, the intestinal inflammation that developed in recipients of Stat6−/−Tbx21−/− T cells could be blocked by administration of IL-17A neutralizing antibody, suggesting that the potent inhibitory effect of IL-4/STAT6 signals on Th17 differentiation normally prevent colitis induced by Tbx21−/− T cells37. Various explanations could account for the discrepancy between our study and those earlier findings. First, in contrast to the published reports, we used naïve Tbx21−/− CD4+ T cells from C57BL/6 mice instead of BALB/c mice. An important difference between Tbx21−/− CD4+ T cells from these genetic backgrounds appears to be their differential susceptibility to suppression by IL-4/STAT6 signals. We found that transfer of Tbx21−/− T cells induced IL-17A-dependent colitis despite increased frequencies of IL-4-expressing cells in the intestine. This discrepancy may be due to higher amounts of IL-4 produced by activated CD4+ T cells from BALB/c versus C57BL/6 mice45, leading to the well-described Th2-bias of the BALB/c strain45. Second, differences in the composition of the intestinal microbiota between animal facilities can have a substantial effect on skewing CD4+ T cells responses. In particular, the Clostridium-related segmented filamentous bacteria (SFB) have been shown to drive the emergence of IL-17 and IL-22 producing CD4+ T cells in the intestine46. Importantly, the ability of naïve CD4+ T cells to induce colitis is dependent on the presence of intestinal bacteria, as germ-free mice do not develop pathology upon T cell transfer47. In line with this, we previously described that colonization of germ-free mice with intestinal microbiota containing SFB was necessary to restore the development of colitis47. Since our Rag1−/− colony is SFB+ and the presence of SFB was not reported in the previous studies, it is possible that differences in SFB colonization status contributed to the observed differences in pathogenicity ofTbx21−/− T cells.

It is important to note that T-bet-deficient T cells did not induce more severe colitis than WT T cells but rather promoted a distinct mucosal inflammatory response. Colitis induced by WT T cells is characterized by a multifunctional response with high amounts of IFN-γ and GM-CSF and a lower IL-17A and IL-22 response. Consistent with this, we have shown that blockade of GM-CSF abrogates T cell transfer colitis48 as well as bacteria-driven intestinal inflammation49 in T-bet sufficiency whereas blockade of IL-17A or IL-22 fails to do so. By contrast T-bet deficiency leads to production of high amounts of IL-17A and IL-22 in the colon and neutralization of either was sufficient to reduce intestinal pathology. Our in vitro experiments suggest that IL-17A and IL-22 synergise to promote intestinal epithelial cell responses, which may in part explain the efficacy of blocking IL-17A or IL-22 in colitis induced by T-bet-deficient T cells. A similar synergistic interplay has been described in the lung where IL-22 served a tissue protective function in homeostasis but induced airway inflammation in the presence of IL-17A (ref. 50). This highlights the complexity of the system in health and disease, and the need for a controlled production of both cytokines. We describe here only one mechanism of how IL-17A/IL-22 induce a context-specific epithelial cell response that potentially impacts on the order or composition of immune cell infiltration. Overall, these results provide a new perspective on T-bet, revealing its role in shaping the qualitative nature of the IL-23-driven colitogenic T cell response.

We also describe here the unexpected finding that a substantial proportion of T-bet-deficient intestinal T cells retain the ability to express IFN-γ. To investigate the potential mechanisms responsible for T-bet-independent IFN-γ production by intestinal CD4+ T cells we focused on two transcription factors, Runx3 and Eomes. Runx3 has been shown to promote IFN-γ expression directly through binding to the Ifng promoter38 and Eomes is known to compensate for IFN-γproduction in T-bet-deficient Th1 cells37. We found IL-23-mediated induction of Runx3 protein in WT and Tbx21−/− T cells isolated from the intestine, thus identifying Runx3 downstream of IL-23R signalling. By contrast, we could only detect Eomes protein and its induction by IL-23 in T-bet-deficient but not WT T cells. Thus, Runx3 and Eomes are activated in response to IL-23 in T-bet-deficient cells and are likely to be drivers of T-bet-independent IFN-γ production. In support of this we found that the majority of T-bet-deficient IL-17AIFN-γ+ T cells expressed Eomes. However, only a minor population of IL-17A+IFN-γ+ T cells stained positive for Eomes, suggesting the existence of alternative pathways for IFN-γ production by Th17 cells. Intriguingly, a recent study identified Runx3 and Runx1 as the transcriptional regulators critical for the differentiation of IFN-γ-producing Th17 cells51. The author’s demonstrated that ectopic expression of Runx transcription factors was sufficient to induce IFN-γ production by Th17 cells even in the absence of T-bet. These findings, combined with our data on Runx3 activation downstream of IL-23R signalling strongly suggest that Runx3 rather than Eomes is driving IFN-γ expression by intestinal Th17 cells.

We have not formally addressed the role of IFN-γ in colitis driven by T-bet-deficient T cells. A recent report by Zimmermann et al.52 found that antibody-mediated blockade of IFN-γ ameliorates colitis induced by WT or T-bet-deficient T cells suggesting IFN-γ also contributes to the colitogneic response mediated by T-bet-deficient T cells as originally described for WT T cells53, 54. By contrast with our results the Zimmerman study found that IL-17A blockade exacerbated colitis following transfer of Tbx21−/− T cells. The reason for the differential role of IL-17A in the two studies is not clear but it is notable that the Zimmerman study was performed in the presence of co-infection with SFB and Hh, and this strong inflammatory drive may alter the pathophysiological role of particular cytokines. Together the data indicate that T-bet deficiency in T cells does not impede their colitogenic activity but that the downstream effector cytokines of the response are context dependent.

In conclusion, our data further underline the essential role for IL-23 in intestinal inflammation and demonstrate that T-bet is an important modulator of the IL–23-driven effector T cell response. The colitogenic T cell response in a T-bet sufficient environment is multifunctional with a dominant GM-CSF and IFN-γ response. By contrast T-bet-deficient colitogenic responses are dominated by IL-17A and IL-22-mediated immune pathology. These results may have significant bearing on human IBD where it is now recognized that differential responsiveness to treatment may reflect considerable disease heterogeneity. As such, identification of suitable biomarkers such as immunological parameters, that allow stratification of patient groups, is becoming increasingly important55. Genome-wide association studies have identified polymorphisms in loci related to innate and adaptive immune arms that confer increased susceptibility to IBD. Among these are Th1 (STAT4, IFNG and STAT1) as well as Th17-related genes (RORC, IL23R and STAT3) (refs56, 57). Thus, detailed profiling of the T cell response in IBD patients may help identify appropriate patient groups that are most likely to benefit from therapeutic blockade of certain effector cytokines. Finally, our studies highlight the importance of IL-23 in the intestinal inflammatory hierarchy and suggest that IL-23 could be an effective therapeutic target across a variety of patient groups.

Yale study: How antibodies access neurons to fight infection

 
 

Yale scientists have solved a puzzle of the immune system: how antibodies enter the nervous system to control viral infections. Their finding may have implications for the prevention and treatment of a range of conditions, including herpes and Guillain-Barre syndrome, which has been linked to the Zika virus.

Many viruses — such as West Nile, Zika, and the herpes simplex virus — enter the nervous system, where they were thought to be beyond the reach of antibodies. Yale immunobiologists Akiko Iwasaki and Norifumi Iijima used mice models to investigate how antibodies could gain access to nerve tissue in order to control infection.

In mice infected with herpes, they observed a previously under-recognized role of CD4 T cells, a type of white blood cell that guards against infection by sending signals to activate the immune system. In response to herpes infection, CD4 T cells entered the nerve tissue, secreted signaling proteins, and allowed antibody access to infected sites. Combined, CD4 T cells and antibodies limited viral spread.

“This is a very elegant design of the immune system to allow antibodies to go to the sites of infection,” said Iwasaki. “The CD4 T cells will only go to the site where there is a virus. It’s a targeted delivery system for antibodies.”

Access of protective antiviral antibody to neuronal tissues requires CD4 T-cell help

Norifumi Iijima & Akiko Iwasaki
Nature 533,552–556 (26 May 2016)
    http://dx.
doi.org:/10.1038/nature17979

Circulating antibodies can access most tissues to mediate surveillance and elimination of invading pathogens. Immunoprivileged tissues such as the brain and the peripheral nervous system are shielded from plasma proteins by the blood–brain barrier1 and blood–nerve barrier2, respectively. Yet, circulating antibodies must somehow gain access to these tissues to mediate their antimicrobial functions. Here we examine the mechanism by which antibodies gain access to neuronal tissues to control infection. Using a mouse model of genital herpes infection, we demonstrate that both antibodies and CD4 T cells are required to protect the host after immunization at a distal site. We show that memory CD4 T cells migrate to the dorsal root ganglia and spinal cord in response to infection with herpes simplex virus type 2. Once inside these neuronal tissues, CD4 T cells secrete interferon-γ and mediate local increase in vascular permeability, enabling antibody access for viral control. A similar requirement for CD4 T cells for antibody access to the brain is observed after intranasal challenge with vesicular stomatitis virus. Our results reveal a previously unappreciated role of CD4 T cells in mobilizing antibodies to the peripheral sites of infection where they help to limit viral spread.

T Cells Help Reverse Ovarian Cancer Drug Resistance

http://www.genengnews.com/gen-news-highlights/t-cells-help-reverse-ovarian-cancer-drug-resistance/81252753/

http://www.genengnews.com/Media/images/GENHighlight/116057_web2151982472.jpg

T cells (red) attack ovarian cancer cells (green). [University of Michigan Health System]

Researchers at the University of Michigan have recently published the results from a new study that they believe underscores why so many ovarian tumors develop resistance to chemotherapy. The tumor microenvironment is made up of an array of cell types, yet effector T cells and fibroblasts constitute the bulk of the tissue. The investigators believe that understanding the interplay between these two cell types holds the key to how ovarian cancer cells develop resistance.

The new study suggests that the fibroblasts surrounding the tumor work to block chemotherapy, which is why nearly every woman with ovarian cancer becomes resistant to treatment. Conversely, the scientists published evidence that T cells in the microenvironment can reverse the resistance phenotype—suggesting a whole different way of thinking about chemotherapy resistance and the potential to harness immunotherapy drugs to treat ovarian cancer.

“Ovarian cancer is often diagnosed at late stages, so chemotherapy is a key part of treatment,” explained co-senior study author J. Rebecca Liu, M.D., associate professor of obstetrics and gynecology at the University of Michigan. “Most patients will respond to it at first, but everybody develops chemoresistance. And that’s when ovarian cancer becomes deadly.”

Dr. Liu continued, stating that “in the past, we’ve thought the resistance was caused by genetic changes in tumor cells. But we found that’s not the whole story.”

The University of Michigan team looked at tissue samples from ovarian cancer patients and separated the cells by type to study the tumor microenvironment in vitro and in mice. More importantly, the scientists linked their findings back to actual patient outcomes.

The results of this study were published recently in Cell through an article entitled “Effector T Cells Abrogate Stroma-Mediated Chemoresistance in Ovarian Cancer.”

Ovarian cancer is typically treated with cisplatin, a platinum-based chemotherapy. The researchers found that fibroblasts blocked platinum. These cells prevented platinum from accumulating in the tumor and protected tumor cells from being killed off by cisplatin.

http://www.genengnews.com/Media/images/GENHighlight/1s20S0092867416304007fx11564016520.jpg

Diagram depicting how T cells can reverse chemotherapeutic resistance. [Cell, Volume 165, Issue 5, May 19, 2016]

“We show that fibroblasts diminish the nuclear accumulation of platinum in ovarian cancer cells, resulting in resistance to platinum-based chemotherapy,” the authors wrote. “We demonstrate that glutathione and cysteine released by fibroblasts contribute to this resistance.”

T cells, on the other hand, overruled the protection of the fibroblasts. When researchers added the T cells to the fibroblast population, the tumor cells began to die off.

“CD8+ T cells abolish the resistance by altering glutathione and cystine metabolism in fibroblasts,” the authors explained. “CD8+ T-cell-derived interferon (IFN)γ controls fibroblast glutathione and cysteine through upregulation of gamma-glutamyltransferases and transcriptional repression of system xccystine and glutamate antiporter via the JAK/STAT1 pathway.”

By boosting the effector T cell numbers, the researchers were able to overcome the chemotherapy resistance in mouse models. Moreover, the team used interferon, an immune cell-secreted cytokine, to manipulate the pathways involved in cisplatin.

“T cells are the soldiers of the immune system,” noted co-senior study author Weiping Zou, M.D., Ph.D., professor of surgery, immunology, and biology at the University of Michigan. “We already know that if you have a lot of T cells in a tumor, you have better outcomes. Now we see that the immune system can also impact chemotherapy resistance.”

The researchers suggest that combining chemotherapy with immunotherapy may be effective against ovarian cancer. Programmed death ligand 1 (PD-L1) and PD-1 pathway blockers are currently FDA-approved treatments for some cancers, although not ovarian cancer.

“We can imagine re-educating the fibroblasts and tumor cells with immune T cells after chemoresistance develops,” Dr. Zou remarked.

“Then we could potentially go back to the same chemotherapy drug that we thought the patient was resistant to. Only now we have reversed that, and it’s effective again,” Dr. Liu concluded.

Effector T Cells Abrogate Stroma-Mediated Chemoresistance in Ovarian Cancer

Weimin Wang, Ilona Kryczek, Lubomír Dostál, Heng Lin, Lijun Tan, et al.
Cell May 2016;  165, Issue 5:1092–1105.   http://dx.doi.org/10.1016/j.cell.2016.04.009
 
Highlights
  • Fibroblasts diminish platinum content in cancer cells, resulting in drug resistance
  • GSH and cysteine released by fibroblasts contribute to platinum resistance
  • T cells alter fibroblast GSH and cystine metabolism and abolish the resistance
  • Fibroblasts and CD8+ T cells associate with patient chemotherapy response

Summary

Effector T cells and fibroblasts are major components in the tumor microenvironment. The means through which these cellular interactions affect chemoresistance is unclear. Here, we show that fibroblasts diminish nuclear accumulation of platinum in ovarian cancer cells, resulting in resistance to platinum-based chemotherapy. We demonstrate that glutathione and cysteine released by fibroblasts contribute to this resistance. CD8+ T cells abolish the resistance by altering glutathione and cystine metabolism in fibroblasts. CD8+ T-cell-derived interferon (IFN)γ controls fibroblast glutathione and cysteine through upregulation of gamma-glutamyltransferases and transcriptional repression of system xc cystine and glutamate antiporter via the JAK/STAT1 pathway. The presence of stromal fibroblasts and CD8+ T cells is negatively and positively associated with ovarian cancer patient survival, respectively. Thus, our work uncovers a mode of action for effector T cells: they abrogate stromal-mediated chemoresistance. Capitalizing upon the interplay between chemotherapy and immunotherapy holds high potential for cancer treatment.

Activation of effect or T cells leads to increased glucose uptake, glycolysis, and lipid synthesis to support growth and proliferation. Activated T cells were identified with CD7, CD5, CD3, CD2, CD4, CD8 and CD45RO. Simultaneously, the expression of CD95 and its ligand causes apoptotic cells death by paracrine or autocrine mechanism, and during inflammation, IL1-β and interferon-1α..
The receptor glucose, Glut 1, is expressed at a low level in naive T cells, and rapidly induced by Myc following T cell receptor (TCR) activation. Glut1 trafficking is also highly regulated, with Glut1 protein remaining in intracellular vesicles until T cell activation.
CD28 co-stimulation further activates the PI3K/Akt/mTOR pathway in particular, and provides a signal for Glut1 expression and cell surface localization.
Mechanisms that control T cell metabolic reprogramming are now coming to light, and many of the same oncogenes importance in cancer metabolism are also crucial to drive T cell metabolic transformations, most notably Myc, hypoxia inducible factor (HIF)1a, estrogen-related receptor (ERR) a, and the mTOR pathway. The proto-oncogenic transcription factor, Myc, is known to promote transcription of genes for the cell cycle, as well as aerobic glycolysis and glutamine metabolism.
Recently, Myc has been shown to play an essential role in inducing the expression of glycolytic and glutamine metabolism genes in the initial hours of T cell activation. In a similar fashion, the transcription factor (HIF)1a can up-regulate glycolytic genes to allow cancer cells to survive under hypoxic conditions

UPDATE 6/11/2021

Bispecific Antibodies Emerging as Effective Cancer Therapeutics

In Perspectives in the Journal Science

Bispecific antibodies

Source: https://science.sciencemag.org/content/372/6545/916

 See all authors and affiliations

Science  28 May 2021:
Vol. 372, Issue 6545, pp. 916-917
DOI: 10.1126/science.abg1209

Bispecific antibodies (bsAbs) bind two different epitopes on the same or different antigens. Through this dual specificity for soluble or cell-surface antigens, bsAbs exert activities beyond those of natural antibodies, offering numerous opportunities for therapeutic applications. Although initially developed for retargeting T cells to tumors, with a first bsAb approved in 2009 (catumaxomab, withdrawn in 2017), exploring new modes of action opened the door to many additional applications beyond those of simply combining the activity of two different antibodies within one molecule. Examples include agonistic “assembly activities” that mimic the activity of natural ligands and cofactors (for example, factor VIII replacement in hemophilia A), inactivation of receptors or ligands, and delivery of payloads to cells or tissues or across biological barriers. Over the past years, the bsAb field transformed from early research to clinical applications and drugs. New developments offer a glimpse into the future promise of this exciting and rapidly progressing field.

Monoclonal antibodies (mAbs) comprise antigen-binding sites formed by the variable domains of the heavy and light chain and an Fc region that mediates immune responses. BsAbs, produced through genetic engineering, combine the antigen-binding sites of two different antibodies within one molecule, with a plethora of formats available (1). Conceptually, one can discriminate between bsAbs with combinatorial modes of action where the antigen-binding sites act independently from each other, and bsAbs with obligate modes of action where activity needs binding of both, either in a sequential (temporal) way or dependent on the physical (spatial) linkage of both (see the figure) (2). BsAbs approved as drugs are so far in the obligate dual-binding category: A T cell recruiter (blinatumomab) against cancer and a factor VIIIa mimetic to treat hemophilia A (emicizumab). Most but not all of the more than 100 bsAbs in clinical development address cancers. Some are in late stage (such as amivantamab, epcoritamab, faricimab, and KNO46), but most are still in early stages (2). Most of these entities enable effector cell retargeting to induce target cell destruction.

An increasing number of programs also explore alternative modes of action. This includes bsAbs that target pathways involved in tumor proliferation (such as amivantamab), invasion, ocular angiogenesis (such as faricimab), or immune regulation by blocking receptors and/or ligands, mainly in a combinatorial manner. Challenges for all of these entities are potential adverse effects, toxicity in normal tissues, and overshooting and systemic immune responses, especially with T cell retargeting or immune-modulating or activating entities. Such issues need to be carefully addressed.

Most of the bispecific T cell engagers comprise a binding site for a tumor-associated antigen and CD3 [a component of the T cell receptor (TCR) activation complex] as trigger molecule on T cells. To prevent or ameliorate “on-target, off-tumor” effects of T cell recruiters, approaches currently investigated include the modulation of target affinities and mechanisms to allow conditional activation upon target cell binding. Thus, a reduced affinity for CD3 increased tolerability by reducing peripheral cytokine concentrations that are associated with nonspecific or overshooting immune reactions (3). Similarly, reduced affinity for the target antigen was shown to ameliorate cytokine release and damage of target-expressing tissues (4). Tumor selectivity can be further increased by implementing avidity effects—for example, by using 2+1 bsAb formats with two low-affinity binding sites for target antigens and monovalent binding to CD3 (4).

In further approaches, binders to CD3 were identified that efficiently trigger target cell destruction without inducing undesired release of cytokines, demonstrating the importance of epitope specificity to potentially uncouple efficacy from cytokine release (5). Complementing these T cell–recruiting principles, the nonclassical T cell subset of γ9d2 T cells with strong cytotoxic activity emerged as potent effectors, which can be retargeted with bsAbs binding to the γ9d2 TCR. Thereby, global activation of all T cells, including inhibitory regulatory T cells (Treg cells), through CD3 binding, may be avoided (6). However, even these approaches might result in a narrow therapeutic window to treat solid tumors because of T cell activation in normal tissues.

Consequently, there are several approaches to conditionally activate T cells within tumors, including a local liberation of the CD3-binding sites or triggering local assembly of CD3-binding sites from two half-molecules. For example, CD3-binding sites have been masked by fusing antigen binding or blocking moieties—such as peptides, aptamers, or anti-idiotypic antibody fragments—to one or both variable domains. These moieties are released within the tumor by tumor-associated proteases, or through biochemical responses to hypoxia or low pH (7). This approach can also be applied to confer specific binding of antibody therapeutics, including bsAbs, to antigens on tumor cells (8).

An on-target restoration of CD3-binding sites requires application of two target-binding entities, each comprising parts of the CD3-binding site, which assemble into functional binding sites upon close binding of both half-antibodies. The feasibility of this approach was recently shown, for example, for a split T cell–engaging antibody derivative (Hemibody) that targets a cell surface antigen (9). Such approaches can also be applied to half-antibodies that recognize two different targets expressed on the same cell, further increasing tumor selectivity.

Regarding T cell engagers, increasing efforts are made to target not only cell-surface antigens expressed on tumor cells but also human leukocyte antigen (HLA)–presented tumor-specific peptides. This expands the target space of bsAbs toward tumor-specific intracellular antigens and can be achieved by using either recombinant TCRs or antibodies with TCR-like specificities combined with, for example, CD3-binding arms to engage T cell responses. A first TCR–anti-CD3 bispecific molecule is in phase I and II trials to treat metastatic melanoma (10). A challenge of this approach is the identification of TCRs or TCR-like antibodies that bind the peptide in the context of HLA with high affinity and specificity, without cross-reacting with related peptides to reduce or avoid off-target activities. Comprehensive screening tools and implementation of computational approaches are being developed to achieve this task.

A rapidly growing area of bsAbs in cancer therapy is their use to foster antitumor immune responses. Here, they are especially applied for dual inhibition of checkpoints that prevent immune responses—for example, programmed cell death protein 1 (PD-1) and its ligand (PD-L1), cytotoxic T lymphocyte–associated antigen 4 (CTLA-4), or lymphocyte activation gene 3 (LAG-3; for example, KNO46). Tumor-targeted bsAbs can also target costimulatory factors such as CD28 or 4-1BB ligand (4-1BBL) to enhance T cell responses when combined with PD-1 blockade or to provide an activity-enhancing costimulatory signal in combination with CD3-based bsAbs (11). Furthermore, bsAbs are being developed for local effects by targeting one arm to antigens that are expressed by tumor cells or cells of the tumor microenvironment (2).

Clinical application of bsAbs now expands to other therapeutic areas, including chronic inflammatory, autoimmune, and neurodegenerative diseases; vascular, ocular, and hematologic disorders; and infections. In contrast to mAbs, bsAbs can inactivate the signaling of different cytokines with one molecule to treat inflammatory diseases (12). Simultaneous dual-target binding is not essential to elicit activity for bsAbs against combinations of proinflammatory cytokines, such as tumor necrosis factor (TNF), interleukin-1α (IL-1α), IL-1β, IL-4, IL-13, IL-17, inducible T cell costimulator ligand (ICOSL), or B cell–activating factor (BAFF). This presumably also applies to blockade of immune cell receptors, although dual targeting might confer increased efficacy due to avidity effects and increased selectivity through simultaneous binding of two different receptors.

A further application of combinatorial dual targeting is in ophthalmology. Loss of vision in wet age-related macular degeneration (AMD) results from abnormal proliferation and leakiness of blood vessels in the macula. This can be treated with antibodies that bind and inactivate factors that stimulate their proliferation (13). In contrast to mAbs or fragments that recognize individual factors, bsAbs bind two such factors. For example, faricimab that binds vascular endothelial growth factor A (VEGF-A) and angiopoietin-2 (ANG2), demonstrated dual efficacy in preclinical studies, and is currently in phase 3 trials.

BsAbs with obligate modes of action that mandate simultaneous dual-target binding are “assemblers” that replace the function of factors necessary to form functional protein complexes. One of these bsAbs with an assembly role (emicizumab, approved in 2018) replaces factor VIIIa in the clotting cascade. Deficiency of factor VIII causes hemophilia A, which can be overcome by substitution with recombinant factor VIII. However, a proportion of patients develop factor VIII–neutralizing immune responses and no longer respond to therapy. To overcome this, a bsAb was developed with binding sites that recognize and physically connect factors IXa and X, a process normally mediated by factor VIIIa. Extensive screening of a large set of bsAbs was required to identify those that combine suitable epitopes with optimized affinities and geometry to serve as functional factor VIIIa mimetics (14). This exemplifies the complexity of identifying the best bsAb for therapeutic applications.

A mode of action requiring sequential binding of two targets is the transport of bsAbs across the blood-brain barrier (BBB). This is a tight barrier of brain capillary endothelial cells that controls the transport of substances between the blood and the cerebrospinal fluid—the brain parenchyma. Passage of large molecules, including antibodies, across the BBB is thereby restricted. Some proteins, such as transferrin or insulin, pass through the BBB by way of transporters on endothelial cells. Antibodies that bind these shuttle molecules, such as the transferrin receptor (TfR), can hitchhike across the BBB. BsAbs that recognize brain targets (such as β-amyloid for Alzheimer’s disease) and TfR with optimized affinities, epitopes, and formats can thereby enter the brain. Such bsAbs are currently in clinical evaluation to treat neurodegenerative diseases (15).

In the past years, there has been a transition from a technology-driven phase, solving hurdles to generate bsAbs with defined composition, toward exploring and extending the modes of action for new therapeutic options. The challenge of generating bsAbs is not only to identify suitable antigen pairs to be targeted in a combined manner. It is now recognized that the molecular composition has a profound impact on bsAb functionality (13). That more than 30 different bsAb formats are in clinical trials proves that development is now driven by a “fit for purpose” or “format defines function” rationale. Many candidates differ in their composition, affecting valency, geometry, flexibility, size, and half-life (1). Not all members of this “zoo of bsAb formats” qualify to become drugs. Strong emphasis is therefore on identifying candidates that exhibit drug-like properties and fulfill safety, developability, and manufacturability criteria. There is likely to be an exciting new wave of bsAb therapeutics available in the coming years.

References and Notes

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Programmed Cell Death and Cancer Therapy

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

Programmed Death: A Cat and Mouse Game

 http://www.cancernetwork.com/blog/programmed-death-cat-and-mouse-game

Prologue: The world of cancer care has been shaken up by the news that patients with hard-to-treat tumors benefit from a new type of immunotherapy, called checkpoint inhibition. A key receptor, called programmed death 1 (PD-1), is charged with suppressing the ability of activated T cells and other immune cells to destroy cancer cells, all in the name of preventing damage to normal tissue via autoimmunity. When PD-1 receptors on T cells bind with PD-L1 and PD-L2, complimentary receptors expressed on tumor cells, the immune response (call it the assassination of the cell) is checked and the tumor lives on. The anti PD-1 monoclonal antibodies nivolumab and pembrolizumab keep PD-L1 from turning off T cells, which has produced durable responses in several tumor types including melanoma, lung cancer, and renal cell carcinoma and represents a new hope for many.

Oncologists are excited to relay this news to patients, but is there a way to explain this without putting everyone in the room to sleep? Well, I like to use analogies to make seemingly complicated mechanisms easier to understand and the PD-1/PD-L1 relationship has inspired several colorful examples, to wit:

“Think of T cells as killers that use photographs to identify individual bad guys. Their weakness is that they will not act if the intended victim shakes their hand first. The bad guys used to be born without arms, but over time they evolved to grow arms and hands, thus avoiding elimination. The antibodies are boxing gloves that cover the hands of the T cells. Goodbye, bad guys.”

“Think of T cells as cats specially trained to eliminate mice wherever they hide. Their only weakness is if they smell catnip they will roll over and purr like idiots instead of doing their job. The mice then develop special glands that secrete catnip, thus pacifying the kitties. Solution: plug up the cats’ noses with nivolumab or pembrolizumab. Sayonara, Mr. Mouse.”

“Think of T cells as a fire sprinkler system designed to activate when a metal plug is heated to its melting point, releasing water from a pipe. The fire then emits a toxin that coats the fusible metal, keeping it below its melting point. By fitting a protective shield around the plug we block the toxic molecules and allow the plug to melt in a fire. The shield is the monoclonal antibody against PD-1 and thus the fire is successfully extinguished.”

This is getting exhausting, so I think I will stop, but don’t you agree that the concept of checkpoint inhibition lends itself to a plethora of metaphors? Now for the next lesson: how to explain chimeric antigen receptor T-cell therapy to patients. Hold on—I think I need to explain it to myself first.

 

As an clinical immunologist, i agree with the concept, looks pretty straightforward but definitely much more complex as our immune system work like a network. I would appreciate clinical trial data with statistical significance.

 

Much more confusing. Most people understand simplified concepts.

“Some cancer cells turn off your immune systems ability to recognise them. These drugs ramp up the immune system and prevent the cancer cells from hiding. This allows your cells to attack and kill cancer cells”

If i think patient seem to have better ability to understand I say “the drugs block the “off switch” that cancer cells use to escape their detection. This turns your immune systems ability to attack and kill cancer cells back on”

I haven’t had one patient that has looked confused since.

 

HDAC Inhibitors Enhance Immunotherapy Efficacy in Lung Cancer

http://www.oncotherapynetwork.com/lung-cancer-targets/hdac-inhibitors-enhance-immunotherapy-efficacy-lung-cancer

Histone deacetylase (HDAC) inhibitors like romidepsin might improve the efficacy of programmed cell death-1 (PD-1) blockade in lung cancer, suggest preclinical findings reported in the journal Clinical Cancer Research.

Most lung cancer patients’ tumors do not respond to immune checkpoint blockade agents like those that target PD-1. One possible mechanism underlying tumor resistance to PD-1 blockade is the failure of sufficient numbers of T cells to infiltrate tumor tissue.

Hypothesizing that upregulating T-cell chemokine expression and thereby T-cell infiltration of tumors would improve PD-1 blockade’s efficacy against lung tumors, the research team went hunting for FDA-approved oncology agents that induce chemokine expression. Screening 97 approved agents, they found one class that did: HDAC inhibitors.

The HDAC-inhibiting agent romidepsin significantly increased T-cell tumor infiltration and impacted lung tumor growth in mouse models, the team reported—and when romidepsin was subsequently combined with PD-1 blockade in several lung tumor models, the combination showed greater antitumor activity than either agent on its own.

“These results suggest that combination of HDAC inhibitors with PD-1 blockade represent a promising strategy for lung cancer treatment,” said senior study author Amer A. Beg, PhD, of the Moffitt Cancer Center’s Immunology Program, in a news release.

Romidepsin and other HDAC inhibitors have already been approved by the FDA for use against lymphoma and other hematologic cancers, Dr. Beg noted.

The combination will next be tested in several clinical trials, including a study of patients diagnosed with non-small cell lung cancer (NSCLC) at Moffitt Cancer Center.

 

HDAC inhibitors enhance T cell chemokine expression and augment response to PD-1 immunotherapy in lung adenocarcinoma

Hong Zheng1,  weipeng zhao2Cihui Yan3Crystina C Watson4,…., Brian Ruffell13, and Amer A Beg4,*

Clin Cancer Res March 10, 2016; http://dx.doi.org:/10.1158/1078-0432.CCR-15-2584

Purpose: A significant limitation of checkpoint blockade immunotherapy is the relatively low response rate (e.g. ~20% with PD-1 blockade in lung cancer). In this study, we tested whether strategies which increase T cell infiltration to tumors can be efficacious in enhancing immunotherapy response. Experimental Design: We performed an unbiased screen to identify FDA-approved oncology agents with ability to enhance T cell chemokine expression with the goal of identifying agents capable of augmenting immunotherapy response. Identified agents were tested in multiple lung tumor models as single agents and in combination with PD-1 blockade. Additional molecular and cellular analysis of tumors was used to define underlying mechanisms. Results: We found that histone deacetylase (HDAC) inhibitors (HDACi) increased expression of multiple T cell chemokines in cancer cells, macrophages and T cells. Using the HDACi romidepsin in vivo, we observed increased chemokine expression, enhanced T cell infiltration, and T cell-dependent tumor regression. Importantly, romidepsin significantly enhanced the response to PD-1 blockade immunotherapy in multiple lung tumor models, including nearly complete rejection in two models. Combined romidepsin and PD-1 blockade also significantly enhanced activation of tumor-infiltrating T cells. Conclusions: These results provide evidence for a novel role of HDACs in modulating T cell chemokine expression in multiple cell types. In addition, our findings indicate that pharmacological induction of T cell chemokine expression represents a conceptually novel approach for enhancing immunotherapy response. Finally, these results suggest that combination of HDAC inhibitors with PD-1 blockade represents a promising strategy for lung cancer treatment.

 

Cancer Cell Survival Driven by Novel Metabolic Pathway

http://www.genengnews.com/gen-news-highlights/cancer-cell-survival-driven-by-novel-metabolic-pathway/81252584/

Researchers have identified a novel metabolic pathway that helps cancer cells thrive in conditions that are lethal to normal cells. [National Cancer Institute, NIH] http://www.genengnews.com/Media/images/GENHighlight/thumb_28216_large1422477191.jpg

Being attached to the extracellular matrix (ECM) provides cells with numerous advantages for survival, for instance, receiving much needed growth stimuli. However, for malignant cells to function, they must overcome their anchorage-dependent growth—a scenario that is associated with increased production of reactive oxygen species (ROS) and altered glucose metabolism.

Now, researchers at the Children’s Medical Center Research Institute at UT Southwestern (CRI) believe they have uncovered a novel metabolic pathway that helps cancer cells thrive in conditions that would otherwise be lethal to healthy cells.

“It’s long been thought that if we could target tumor-specific metabolic pathways, it could lead to effective ways to treat cancer,” explained senior study author Ralph DeBerardinis, M.D., Ph.D.,  associate professor, and director of CRI’s Genetic and Metabolic Disease Program. “This study finds that two very different metabolic processes are linked in a way that is specifically required for cells to adapt to the stress associated with cancer progression.”

This new study describes an alternate version of two well-known metabolic pathways, the pentose phosphate pathway (PPP) and the Krebs cycle, to defend against ROS that destroy cells via oxidative stress.

The findings from this study were published recently in Nature in an article entitled “Reductive Carboxylation Supports Redox Homeostasis During Anchorage-Independent Growth.”

Previous work from Dr. DeBerardinis’ laboratory found that the Krebs cycle, a series of chemical reactions that cells use to generate energy, could reverse itself under certain conditions to nourish cancer cells.

Dr. DeBerardinis also noted that cells “are dependent on matrix attachment to receive growth-promoting signals and to regulate their metabolism in a way that supports cell growth, proliferation, and survival.” Detachment from the matrix results in a sudden increase in ROS that is lethal to normal cells. Yet, cancer cells seem to have evolved workaround.

A landmark study from 2009 elucidated that healthy cells were destroyed when detached from the ECM. Moreover, in the same study, investigators found that inserting an oncogene into a normal cell caused it to behave like a cancer cell and survive detachment.

“Another Nature study, this one from CRI Director Dr. Sean Morrison’s laboratory in November 2015, found that the rare skin cancer cells that were able to detach from the primary tumor and successfully metastasize to other parts of the body had the ability to keep ROS levels from getting dangerously high,” Dr. DeBerardinis remarked.

Dr. DeBerardinis and his team worked from the premise that the two findings were pieces of the same puzzle and that a crucial part of the picture seemed to be missing.

It had been well known that the PPP was an important source of nicotine adenine dinucleotide phosphate (NADPH), which provides a source of reducing electrons to scavenge ROS; however, the PPP produces NADPH in the cytosol, whereas the ROS are generated primarily in another subcellular structure called the mitochondria.

“If you think of ROS as fire, then NADPH is like the water used by cancer cells to douse the flames,” Dr. DeBerardinis noted.  But how could NADPH from the PPP help deal with the stress of ROS produced in an entirely different part of the cell? “What we did was to discover how this happens.”

The CRI team was able to demonstrate that cancer cells use a “piggybacking” system to carry the reducing electron from the PPP into the mitochondria. This movement involves an unusual reaction in the cytosol that transfers reducing equivalents from NADPH to a molecule called citrate, similar to a reversed reaction of the Krebs cycle.The citrate then enters the mitochondria and stimulates another pathway that results in the release of reducing electrons to produce NADPH right at the location of ROS creation, allowing the cancer cells to survive and grow without the benefit of matrix attachment.

“We knew that both the PPP and Krebs cycle provide metabolic benefits to cancer cells. But we had no idea that they were linked in this unusual fashion,” Dr. DeBerardinis stated. “Strikingly, normal cells were unable to transport NADPH by this mechanism, and died as a result of the high ROS levels.”

The researchers stressed that their findings were based on cultured cell models and more research will be necessary to test the role of the pathway in living organisms.

“We are particularly excited to test whether this pathway is required for metastasis because cancer cells need to survive in a matrix-detached state in the circulation in order to metastasize,” Dr. DeBerardinis concluded.

 

Reductive carboxylation supports redox homeostasis during anchorage-independent growth

Lei JiangAlexander A. ShestovPamela SwainChendong Yang, …., Brian P. DrankaBenjamin Schwartz & Ralph J. DeBerardinis

Nature(2016)      http://dx.doi.org:/10.1038/nature17393

Cells receive growth and survival stimuli through their attachment to an extracellular matrix (ECM)1. Overcoming the addiction to ECM-induced signals is required for anchorage-independent growth, a property of most malignant cells2. Detachment from ECM is associated with enhanced production of reactive oxygen species (ROS) owing to altered glucose metabolism2. Here we identify an unconventional pathway that supports redox homeostasis and growth during adaptation to anchorage independence. We observed that detachment from monolayer culture and growth as anchorage-independent tumour spheroids was accompanied by changes in both glucose and glutamine metabolism. Specifically, oxidation of both nutrients was suppressed in spheroids, whereas reductive formation of citrate from glutamine was enhanced. Reductive glutamine metabolism was highly dependent on cytosolic isocitrate dehydrogenase-1 (IDH1), because the activity was suppressed in cells homozygous null for IDH1 or treated with an IDH1 inhibitor. This activity occurred in absence of hypoxia, a well-known inducer of reductive metabolism. Rather, IDH1 mitigated mitochondrial ROS in spheroids, and suppressing IDH1 reduced spheroid growth through a mechanism requiring mitochondrial ROS. Isotope tracing revealed that in spheroids, isocitrate/citrate produced reductively in the cytosol could enter the mitochondria and participate in oxidative metabolism, including oxidation by IDH2. This generates NADPH in the mitochondria, enabling cells to mitigate mitochondrial ROS and maximize growth. Neither IDH1 nor IDH2 was necessary for monolayer growth, but deleting either one enhanced mitochondrial ROS and reduced spheroid size, as did deletion of the mitochondrial citrate transporter protein. Together, the data indicate that adaptation to anchorage independence requires a fundamental change in citrate metabolism, initiated by IDH1-dependent reductive carboxylation and culminating in suppression of mitochondrial ROS.

 

Liquid Biopsy Accurately Detects Mutations in Advanced NSCLC

http://www.oncotherapynetwork.com/lung-cancer/liquid-biopsy-accurately-detects-mutations-advanced-nsclc#sthash.bEPxRkAq.dpuf

Droplet digital polymerase chain reaction (ddPCR)-based plasma genotyping—referred to as liquid biopsy—exhibited perfect specificity in identifying EGFR and KRAS mutations in patients with advanced non–small-cell lung cancer (NSCLC), according to the results of a study published in JAMA Oncology.

“We see plasma genotyping as having enormous potential as a clinical test, or assay—a rapid, noninvasive way of screening a cancer for common genetic fingerprints, while avoiding the challenges of traditional invasive biopsies,” said senior author, Geoffrey Oxnard, MD, thoracic oncologist and lung cancer researcher at Dana-Farber and Brigham and Women’s Hospital, in a press release. “Our study was the first to demonstrate prospectively that a liquid biopsy technique can be a practical tool for making treatment decisions in cancer patients.”

According to the press release, the test proved so reliable in the study that the Dana-Farber/Brigham and Women’s Cancer Center this week became the first medical facility in the country to offer it to all patients with NSCLC, either at the time of first diagnosis or of relapse following previous treatment.

Oxnard and colleagues enrolled 180 patients with advanced NSCLC. Patients were either newly diagnosed with the disease (n = 120) or had acquired resistance to prior EGFR kinase inhibitors (n = 60) and were planned for rebiopsy. Patients underwent initial blood sampling and immediate plasma ddPCR screening for EGFR exon 19 deletion, L858R, the EGFR T790M acquired resistance mutation, or KRAS G12X. In addition, patients underwent biopsy for tissue genotyping used to compare the accuracy of ddPCR.

Among the enrolled patients, 80 had EGFR exon19/L858R mutations, 35 had T790M mutations and 25 had KRAS G12X mutations. The median test turnaround time for liquid biopsy was 3 days. In comparison, the median turnaround time for tissue genotyping was 12 days for newly diagnosed patients and 27 days for patients with acquired EGFR inhibitor resistance.

“This long turnaround time is due largely to the practical reality that many patients with newly diagnosed NSCLC require a repeat biopsy to obtain tissue for genotyping, as do all patients with acquired resistance,” the researchers noted.

The liquid biopsy showed 100% positive predictive value for detecting EGFR 19 deletion, L858R, and KRAS mutations. However, it had only a positive predictive value of 79% for T790M mutations. The sensitivity of the test was lower. ddPCR had a sensitivity of 82% for EGFR 19 deletion, 74% for L858R, 77% for T790M, and 64% for KRAS.

The researchers pointed out that “a key limitation of plasma ddPCR is that although this method is adept at rapidly detecting specific targetable mutations, it cannot easily detect copy number alterations and rearrangements. The ddPCR panel assessed in this study thus cannot currently detect targetable alterations in either ALK or ROS1,” two other common mutations in NSCLC.

In an editorial that accompanied the article, P. Mickey Williams, PhD, of Frederick National Laboratory for Cancer Research, and Barbara A. Conley, MD, from the National Cancer Institute, questioned whether or not these results, and the rapid turnaround time for liquid biopsy, could be replicated widely by other institutions.

“However, if this performance were generally applicable, this would indeed be an advance in clinical care, reducing the proportion of patients requiring biopsy, at least in the resistance setting,” Williams and Conley wrote.

“This study is a step in the right direction of preparing needed clinical validation for the use of ctDNA for detection and serial monitoring of clinically relevant tumor mutations. Owing to low sensitivity and high positive predictive value and specificity, this approach is probably best suited for detection of resistance mutations and for serial plasma testing to assess treatment response, and should not replace tumor biopsy assessment for initial treatment decision-making,” they concluded.

 

Prospective Validation of Rapid Plasma Genotyping for the Detection of EGFR and KRAS Mutations in Advanced Lung Cancer

Adrian G. Sacher, MD1,2; Cloud Paweletz, PhD3; Suzanne E. Dahlberg, PhD4,5; Ryan S. Alden, BSc1; Allison O’Connell, BSc3; Nora Feeney, BSc3; Stacy L. Mach, BA1; Pasi A. Jänne, MD, PhD1,2,3; Geoffrey R. Oxnard, MD1,2

JAMA Oncol. Published online April 07, 2016.    http://dx.doi.org:/10.1001/jamaoncol.2016.0173

Importance  Plasma genotyping of cell-free DNA has the potential to allow for rapid noninvasive genotyping while avoiding the inherent shortcomings of tissue genotyping and repeat biopsies.

Objective  To prospectively validate plasma droplet digital PCR (ddPCR) for the rapid detection of common epidermal growth factor receptor (EGFR) and KRAS mutations, as well as the EGFR T790M acquired resistance mutation.

Design, Setting, and Participants  Patients with advanced nonsquamous non–small-cell lung cancer (NSCLC) who either (1) had a new diagnosis and were planned for initial therapy or (2) had developed acquired resistance to an EGFR kinase inhibitor and were planned for rebiopsy underwent initial blood sampling and immediate plasma ddPCR for EGFR exon 19 del, L858R, T790M, and/or KRAS G12X between July 3, 2014, and June 30, 2015, at a National Cancer Institute–designated comprehensive cancer center. All patients underwent biopsy for tissue genotyping, which was used as the reference standard for comparison; rebiopsy was required for patients with acquired resistance to EGFR kinase inhibitors. Test turnaround time (TAT) was measured in business days from blood sampling until test reporting.

Main Outcomes and Measures  Plasma ddPCR assay sensitivity, specificity, and TAT.

Results  Of 180 patients with advanced NSCLC (62% female; median [range] age, 62 [37-93] years), 120 cases were newly diagnosed; 60 had acquired resistance. Tumor genotype included 80 EGFR exon 19/L858R mutants, 35 EGFR T790M, and 25 KRASG12X mutants. Median (range) TAT for plasma ddPCR was 3 (1-7) days. Tissue genotyping median (range) TAT was 12 (1-54) days for patients with newly diagnosed NSCLC and 27 (1-146) days for patients with acquired resistance. Plasma ddPCR exhibited a positive predictive value of 100% (95% CI, 91%-100%) for EGFR 19 del, 100% (95% CI, 85%-100%) for L858R, and 100% (95% CI, 79%-100%) for KRAS, but lower for T790M at 79% (95% CI, 62%-91%). The sensitivity of plasma ddPCR was 82% (95% CI, 69%-91%) for EGFR 19 del, 74% (95% CI, 55%-88%) for L858R, and 77% (95% CI, 60%-90%) for T790M, but lower for KRAS at 64% (95% CI, 43%-82%). Sensitivity for EGFR or KRAS was higher in patients with multiple metastatic sites and those with hepatic or bone metastases, specifically.

Conclusions and Relevance  Plasma ddPCR detected EGFR and KRAS mutations rapidly with the high specificity needed to select therapy and avoid repeat biopsies. This assay may also detect EGFR T790M missed by tissue genotyping due to tumor heterogeneity in resistant disease.

Plasma genotyping uses tumor-derived cell-free DNA (cfDNA) to allow for rapid noninvasive genotyping of tumors. This technology is currently poised to transition into a treatment decision-making tool in multiple cancer types. It is particularly relevant to the treatment of advanced non–small-cell lung cancer (NSCLC), in which therapy hinges on rapid and accurate detection of targetable epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), and ROS1 alterations.1– 6Plasma genotyping is capable of circumventing many limitations of standard tissue genotyping including slow turnaround time (TAT), limited tissue for testing, and the potential for failed biopsies. It may be particularly useful in directing the rapid use of new targeted therapies for acquired resistance in advanced EGFR-mutant NSCLC, where the need for a repeat biopsy to test for resistance mechanisms has amplified the inherent limitations of traditional genotyping.7,8

The need to carefully validate the test characteristics of each of the myriad individual plasma genotyping assays before use in clinical decision making is paramount. We have previously reported the development of a quantitative droplet digital polymerase chain reaction (ddPCR)-based assay for the detection of EGFR kinase mutations andKRAS codon 12 mutations in plasma.9 The detection of these mutations has the potential to guide treatment by either facilitating targeted therapy with an EGFR tyrosine kinase inhibitor (TKI) or ruling out the presence of other potentially targetable alterations in the case of KRAS.5 Alternative platforms including Cobas, peptide nucleic acid–mediated PCR, multiplexed next-generation sequencing (NGS), high-performance liquid chromatography, and Scorpion–amplified refractory mutation system have also been examined in retrospective analyses of patient samples.10– 22 The test characteristics of these assays have been variable and may be attributable to differences in testing platforms, as well as the retrospective nature of these studies, their smaller size, and the timing of blood collection with respect to disease progression and therapy initiation. The absence of reliable prospective data on the use of specific plasma genotyping assays in advanced NSCLC has left key aspects of its utility largely undefined and slowed its uptake as a tool for clinical care in patients with both newly diagnosed NSCLC and EGFR acquired resistance.

To our knowledge, we have conducted the first prospective study of the use of ddPCR-based plasma genotyping for the detection of EGFR and KRAS mutations. This study was performed in the 2 settings where we anticipate clinical adoption of this assay: (1) patients with newly diagnosed advanced NSCLC and (2) those with acquired resistance to EGFR kinase inhibitors. The primary aim of this study was to prospectively evaluate the feasibility and accuracy of this assay for the detection ofEGFR/KRAS mutations in patients with newly diagnosed NSCLC and EGFR T790M in patients with acquired resistance in a clinical setting. Additional end points included test TAT and the effect of sample treatment conditions on test accuracy.

Key Points
  • Question What is the sensitivity, specificity, turnaround time, and robustness of droplet digital polymerase chain reaction (ddPCR)-based plasma genotyping for the rapid detection of targetable genomic alterations in patients with advanced non–small-cell lung cancer (NSCLC)?

  • Findings In this study of 180 patients with advanced NSCLC (120 newly diagnosed, 60 with acquired resistance to epidermal growth factor receptor [EGFR] kinase inhibitors), plasma genotyping exhibited perfect specificity (100%) and acceptable sensitivity (69%-80%) for the detection of EGFR-sensitizing mutations with rapid turnaround time (3 business days). Specificity was lower for EGFR T790M (63%), presumably secondary to tumor heterogeneity and false-negative tissue genotyping.

  • Meaning The use of ddPCR-based plasma genotyping can detect EGFR mutations with the rigor necessary to direct clinical care. This assay may obviate repeated biopsies in patients with positive plasma genotyping results.

CYP3A7*1C Allele Associated With Poor Outcomes in CLL, Breast, and Lung Cancer

 http://www.oncotherapynetwork.com/breast-cancer-targets/cyp3a71c-allele-associated-poor-outcomes-cll-breast-and-lung-cancer#sthash.7uiD8XFD.dpuf

Patients with the CYP3A7*1C allele suffer higher rates of cancer progression and mortality, possibly because of worse outcomes among patients treated with chemotherapy drugs that are broken down by the enzyme encoded by CYP3A7, according to authors of a retrospective study published in the journal Cancer Research.

“We found that individuals with breast cancer, lung cancer, or CLL [chronic lymphocytic leukemia] who carry one or more copy of the CYP3A7*1C allele tend to have worse outcomes,” said Olivia Fletcher, PhD, a senior investigator at the Breast Cancer Now Toby Robins Research Centre at the Institute of Cancer Research in London, England, in an American Association for Cancer Research (AACR) news release.

Approximately 8% of cancer patients harbor the CYP3A7*1C allele, the coauthors noted. For these patients, it is possible that standard chemotherapy with CYP3A substrates “may not be optimal,” they cautioned.

The team analyzed DNA samples from 1,008 patients with breast cancer, 1,128 patients with lung cancer, and 347 patients with CLL. They found that the CYP3A7*1C-associated single nucleotide polymorphism (SNP) rs45446698 is associated with increased breast cancer mortality (hazard ratio [HR] 1.74; P = .03), all-cause mortality among patients with lung cancer (HR 1.43; P = .009), and progression of CLL (HR 1.62; P = .03). The rs45446698 SNP is one of seven SNPs that form the CYP3A7*1C allele.

The CYP3A7*1C allele is expressed in adults, whereas other variants of CYP3A7 are expressed during fetal development. CYP3A7 encodes an enzyme that degrades estrogen and testosterone, and some anticancer drugs.

“We also found borderline evidence of a statistical interaction between the CYP3A7*1C allele, treatment of patients with a cytotoxic agent that is a CYP3A substrate, and clinical outcome (P = .06),” they noted.

“Even though we did not see a statistically-significant difference when stratifying patients by treatment with a CYP3A7 substrate, the fact that we see the same effect in three very different cancer types suggests to me that it is more likely to be something to do with treatment than the disease itself,” commented Dr. Fletcher. “However, we are looking at ways of replicating these results in additional cohorts of patients and types of cancer, as well as overcoming the limitations of this study.”

Limitations included the retrospective nature of the study and the absence of data on how quickly individual patients metabolized chemotherapeutic agents, she said.

 

Cytochrome P450 AlleleCYP3A7*1C Associates with Adverse Outcomes in Chronic Lymphocytic Leukemia, Breast, and Lung Cancer

Nichola Johnson1,2Paolo De Ieso3Gabriele Migliorini4,….., Gillian Ross12Richard S. Houlston, and Olivia Fletcher1,2,*

Cancer Res March 10, 2016; http://dx.doi.org:/10.1158/0008-5472.CAN-15-1410

CYP3A enzymes metabolize endogenous hormones and chemotherapeutic agents used to treat cancer, thereby potentially affecting drug effectiveness. Here, we refined the genetic basis underlying the functional effects of a CYP3A haplotype on urinary estrone glucuronide (E1G) levels and tested for an association betweenCYP3A genotype and outcome in patients with chronic lymphocytic leukemia (CLL), breast, or lung cancers. The most significantly associated SNP was rs45446698, an SNP that tags the CYP3A7*1Callele; this SNP was associated with a 54% decrease in urinary E1G levels. Genotyping this SNP in 1,008 breast cancer, 1,128 lung cancer, and 347 CLL patients, we found that rs45446698 was associated with breast cancer mortality (HR, 1.74; P = 0.03), all-cause mortality in lung cancer patients (HR, 1.43; P = 0.009), and CLL progression (HR, 1.62; P= 0.03). We also found borderline evidence of a statistical interaction between the CYP3A7*1C allele, treatment of patients with a cytotoxic agent that is a CYP3A substrate, and clinical outcome (Pinteraction = 0.06). The CYP3A7*1C allele, which results in adult expression of the fetal CYP3A7 gene, is likely to be the functional allele influencing levels of circulating endogenous sex hormones and outcome in these various malignancies. Further studies confirming these associations and determining the mechanism by which CYP3A7*1C influences outcome are required. One possibility is that standard chemotherapy regimens that include CYP3A substrates may not be optimal for the approximately 8% of cancer patients who are CYP3A7*1C carriers. Cancer Res; 76(6); 1–9. ©2016 AACR.

 

​Specific Form of CYP3A7 Gene Associated With Poor Outcomes for Patients With Several Cancer Types

3/10/2016

PHILADELPHIA — Among patients with breast cancer, lung cancer, or chronic lymphocytic leukemia (CLL), those who had a specific form of the CYP3A7 gene (CYP3A7*1C) had worse outcomes compared with those who did not have CYP3A7*1C, and this may be related to how the patients metabolize, or break down, the therapeutics used to treat them, according to a study published in Cancer Research, a journal of the American Association for Cancer Research.

“The CYP3A7 gene encodes an enzyme that breaks down all sorts of naturally occurring substances—such as sex steroids like estrogen and testosterone—as well as a wide range of drugs that are used in the treatment of cancer,” saidOlivia Fletcher, PhD, a senior investigator at the Breast Cancer Now Toby Robins Research Centre at The Institute of Cancer Research in London. “The CYP3A7 gene is normally turned on in an embryo and then turned off shortly after a baby is born, but individuals who have one or more copy of the CYP3A7*1C form of the gene [the CYP3A7*1C allele] turn on their CYP3A7 gene in adult life.

“We found that individuals with breast cancer, lung cancer, or CLL who carry one or more copy of the CYP3A7*1C allele tend to have worse outcomes,” continued Fletcher. “One possibility is that these patients break down the drugs that they are given to treat their cancer too fast. However, further independent studies that replicate our findings in larger numbers of patients and rule out biases are needed before we could recommend any changes to the treatment that cancer patients with the CYP3A7*1C allele receive.”

To find out whether the CYP3A7*1C allele was associated with outcome for patients with breast cancer, lung cancer, or CLL, Fletcher and colleagues analyzed DNA samples from 1,008 breast cancer patients, 1,142 patients with lung cancer, and 356 patients with CLL for the presence of a single nucleotide polymorphism (SNP), rs45446698. Fletcher explained that a SNP is a type of genetic variant and that because of the way that we inherit our genetic material from our parents, we tend to inherit clusters of genetic variants. She went on to say that rs45446698 is one of seven SNPs that cluster together, forming the CYP3A7*1C allele.

The researchers found that among the breast cancer patients, rs45446698 (and, therefore, the CYP3A7*1C allele) was associated with a 74 percent increased risk of breast cancer mortality. Among the lung cancer patients, it was associated with a 43 percent increased risk of death from any cause, and among the CLL patients, it was associated with a 62 percent increased risk of disease progression.

Patients who were treated with a chemotherapeutic broken down by CYP3A7 tended to have worse outcomes compared with those treated with other chemotherapeutics, but the difference was not statistically significant.

“Even though we did not see a statistically significant difference when stratifying patients by treatment with a CYP3A7 substrate, the fact that we see the same effect in three very different cancer types suggests to me that it is more likely to be something to do with treatment than the disease itself,” said Fletcher. “However, we are looking at ways of replicating these results in additional cohorts of patients and types of cancer, as well as overcoming the limitations of this study.”

Fletcher explained that the main limitation of the study is that the researchers used samples and clinical information collected for other studies. Therefore, they did not have the same clinical information for each patient, and the samples were collected at different time points and for patients treated with various chemotherapeutics. She also noted that the team were not able to determine how quickly the patients broke down the therapeutics they received as treatment.

The study was supported by Breast Cancer Now, Leukaemia and Lymphoma Research (now known as Bloodwise), Cancer Research UK, the Medical Research Council, the Cridlan Trust, the Helen Rollason Cancer Charity, and Sanofi-Aventis. Funding for the authors’ institutions was received from the National Health Service of the United Kingdom. Fletcher declares no conflicts of interest.

 

Liquid Biopsy for NSCLC

‘Liquid biopsy’ blood test accurately detects key genetic mutations in most common form of lung cancer, study finds.

http://www.technologynetworks.com/Diagnostics/news.aspx?ID=190276

A simple blood test can rapidly and accurately detect mutations in two key genes in non-small cell lung tumors, researchers at Dana-Farber Cancer Institute and other institutions report in a new study – demonstrating the test’s potential as a clinical tool for identifying patients who can benefit from drugs targeting those mutations.

The test, known as a liquid biopsy, proved so reliable in the study that Dana-Farber/Brigham and Women’s Cancer Center (DF/BWCC) expects to offer it soon to all patients with non-small cell lung cancer (NSCLC), either at the time of first diagnosis or of relapse following previous treatment.

…….

“Our study was the first to demonstrate prospectively that a liquid biopsy technique can be a practical tool for making treatment decisions in cancer patients. The trial was such a success that we are transitioning the assay into a clinical test for lung cancer patients at DF/BWCC.”

The study involved 180 patients with NSCLC, 120 of whom were newly diagnosed, and 60 of whom had become resistant to a previous treatment, allowing the disease to recur. Participants’ cell-free DNA was tested for mutations in the EGFR and KRAS genes, and for a separate mutation in EGFR that allows tumor cells to become resistant to front-line targeted drugs. The test was performed with a technique known as droplet digital polymerase chain reaction (ddPCR), which counts the individual letters of the genetic code in cell-free DNA to determine if specific mutations are present. Each participant also underwent a conventional tissue biopsy to test for the same mutations. The results of the liquid biopsies were then compared to those of the tissue biopsies.

The data showed that liquid biopsies returned results much more quickly. The median turnaround time for liquid biopsies was three days, compared to 12 days for tissue biopsies in newly diagnosed patients and 27 days in drug-resistant patients.

Liquid biopsy was also found to be highly accurate. In newly diagnosed patients, the “predictive value” of plasma ddPCR was 100 percent for the primary EGFR mutation and the KRAS mutation – meaning that a patient who tested positive for either mutation was certain to have that mutation in his or her tumor. For patients with the EGFR resistance mutation, the predictive value of the ddPCR test was 79 percent, suggesting the blood test was able to find additional cases with the mutation that were missed using standard biopsies.

Prospective Validation of Rapid Plasma Genotyping for the Detection of EGFRand KRAS Mutations in Advanced Lung Cancer

Adrian G. Sacher, MD1,2; Cloud Paweletz, PhD3; Suzanne E. Dahlberg, PhD, et al.       JAMA Oncol. Published online April 07, 2016.  http://dx.doi.org::/10.1001/jamaoncol.2016.0173

Importance  Plasma genotyping of cell-free DNA has the potential to allow for rapid noninvasive genotyping while avoiding the inherent shortcomings of tissue genotyping and repeat biopsies.

Objective  To prospectively validate plasma droplet digital PCR (ddPCR) for the rapid detection of common epidermal growth factor receptor (EGFR) and KRAS mutations, as well as the EGFR T790M acquired resistance mutation.

Design, Setting, and Participants  Patients with advanced nonsquamous non–small-cell lung cancer (NSCLC) who either (1) had a new diagnosis and were planned for initial therapy or (2) had developed acquired resistance to an EGFR kinase inhibitor and were planned for rebiopsy underwent initial blood sampling and immediate plasma ddPCR for EGFR exon 19 del, L858R, T790M, and/or KRAS G12X between July 3, 2014, and June 30, 2015, at a National Cancer Institute–designated comprehensive cancer center. All patients underwent biopsy for tissue genotyping, which was used as the reference standard for comparison; rebiopsy was required for patients with acquired resistance to EGFR kinase inhibitors. Test turnaround time (TAT) was measured in business days from blood sampling until test reporting.

Main Outcomes and Measures  Plasma ddPCR assay sensitivity, specificity, and TAT.

Results  Of 180 patients with advanced NSCLC (62% female; median [range] age, 62 [37-93] years), 120 cases were newly diagnosed; 60 had acquired resistance. Tumor genotype included 80 EGFR exon 19/L858R mutants, 35 EGFR T790M, and 25 KRASG12X mutants. Median (range) TAT for plasma ddPCR was 3 (1-7) days. Tissue genotyping median (range) TAT was 12 (1-54) days for patients with newly diagnosed NSCLC and 27 (1-146) days for patients with acquired resistance. Plasma ddPCR exhibited a positive predictive value of 100% (95% CI, 91%-100%) for EGFR 19 del, 100% (95% CI, 85%-100%) for L858R, and 100% (95% CI, 79%-100%) for KRAS, but lower for T790M at 79% (95% CI, 62%-91%). The sensitivity of plasma ddPCR was 82% (95% CI, 69%-91%) for EGFR 19 del, 74% (95% CI, 55%-88%) for L858R, and 77% (95% CI, 60%-90%) for T790M, but lower for KRAS at 64% (95% CI, 43%-82%). Sensitivity for EGFR or KRAS was higher in patients with multiple metastatic sites and those with hepatic or bone metastases, specifically.

Conclusions and Relevance  Plasma ddPCR detected EGFR and KRAS mutations rapidly with the high specificity needed to select therapy and avoid repeat biopsies. This assay may also detect EGFR T790M missed by tissue genotyping due to tumor heterogeneity in resistant disease.

 

In this prospective study, we demonstrate the highly specific and rapid nature of plasma genotyping. No false-positive test results were seen for driver mutations inEGFR or KRAS, and TAT from when the specimen was obtained to result was a matter of days. This assay exhibited 100% positive predictive value for the detection of these mutations. Sensitivity was more modest and was directly correlated with both number of metastatic sites and the presence of liver or bone metastases. This newly demonstrated relationship is likely related to increased cfDNA shed in the setting of more extensive disease where tumor cfDNA shed is the chief driver of assay sensitivity and determines its upper limit. The characteristics of plasma ddPCR prospectively demonstrated in this study were similar or improved compared with previous retrospective reports of other cfDNA genotyping assays.10– 13,15,16,24,25 These retrospective studies are smaller, frequently examined a mix of tumor types and/or stages, and lack the careful prospective design needed to demonstrate the readiness of this technology to transition to a tool for selecting therapy. Studies that use retrospective samples from clinical trials that enrolled only EGFR-mutant patients are further limited by an inability to both blind laboratory investigators to tissue genotype and to generalize their assay test characteristics to a genetically heterogeneous real-world patient population.11 These differences and the multiple platforms examined previously have led to variable test characteristics and uncertainty regarding the clinical application of these technologies. This study is the first to prospectively demonstrate the ability of a ddPCR-based plasma genotyping assay to rapidly and accurately detect EGFR and KRAS mutations in a real-world clinical setting with the rigor necessary to support the assertion that use of this assay is capable of directing clinical care.

Even with a diagnostic sensitivity of less than 100%, such a rapid assay with 100% positive predictive value carries the potential for immense clinical utility. The 2- to 3-day TAT contrasts starkly with the 27-day TAT for tumor genotyping seen in patients needing a new tumor biopsy. This long TAT is due largely to the practical reality that many patients with newly diagnosed NSCLC require a repeat biopsy to obtain tissue for genotyping, as do all patients with acquired resistance. Consider the case of 1 study participant, an octogenarian with metastatic NSCLC who had developed acquired resistance to erlotinib with painful bone metastases (Figure 3). Due to the patient’s age and comorbidities, significant concerns existed about the risks of a biopsy and further systemic therapy. A plasma sample was obtained, and within 24 hours ddPCR demonstrated 806 copies/mL of EGFR T790M. A confirmatory lung biopsy was performed, which confirmed EGFR T790M. Treatment with a third-generation EGFR kinase inhibitor, osimertinib mesylate, was subsequently initiated and the patient had a partial response to therapy that was maintained for more than 1 year. The potential of this technology to obviate repeated biopsy in both patients with newly diagnosed NSCLC with insufficient tissue, as well as patients with acquired resistance, is considerable.

A key limitation of plasma ddPCR is that although this method is adept at rapidly detecting specific targetable mutations, it cannot easily detect copy number alterations and rearrangements. The ddPCR panel assessed in this study thus cannot currently detect targetable alterations in either ALK or ROS1. This limitation may potentially be addressed by using targeted NGS of cfDNA for broad, multiplexed detection of complex genomic alterations including ALK and ROS1 rearrangements, although this method is potentially slower than ddPCR-based methods and has been less thoroughly evaluated.23 The potential exists to use these technologies in tandem in advanced NSCLC to facilitate rapid initiation of therapy. Tissue genotyping and repeated biopsy would be specifically used to direct therapy in cases in which plasma genotyping was uninformative due to limitations of assay sensitivity. This approach would be particularly useful in cases of EGFR acquired resistance in which a repeated biopsy for T790M testing could be avoided entirely in many patients. Beyond detecting targetable alterations in order to drive therapy, the identification of nontargetable oncogenic drivers such as KRAS mutations that preclude the presence of other targetable alterations may guide a clinician to rapidly initiate alternative therapies such as chemotherapy or immunotherapy.5 The finding that assay sensitivity is highest in patients with more extensive metastatic disease suggests that those patients most in need of rapid treatment initiation would also be least likely to have false-negative results.

One surprising result of our study was evidence of recurrent false-positive results forEGFR T790M in patients with acquired resistance, despite no false-positive test results for other mutations studied. The sensitivity of the EGFR T790M assay was comparable to that of the EGFR sensitizing mutation assays and similarly related to both disease burden and the presence of liver or bone metastases, which are likely predictive of increased tumor cfDNA shed. We hypothesize that the lower assay specificity is due to the genomic heterogeneity whereby the T790M status of the biopsied site is not representative of all metastatic sites in a patient, a phenomenon supported by mounting evidence in the acquired resistance setting.26,27 This is consistent with the finding that a minority of patients with apparently EGFR T790M tissue-negative disease respond to therapy with third-generation EGFR kinase inhibitors.7,8,28 These observations raise questions regarding the fallibility of tissue-based genotyping as the reference standard for T790M status. The use of plasma genotyping to detect EGFR T790M thus has great potential to identify patients who would benefit from newly approved third-generation EGFR kinase inhibitors but would be unable to access them based on falsely negative tissue genotyping results. Indeed, plasma genotyping may allow more reliable assessment of both T790M status as well as the mechanisms of resistance across all sites of a heterogeneous cancer as opposed to a tissue biopsy and is likely to be an essential tool for future trials targeting drug resistance. The potential to avoid a repeat biopsy entirely in patients in whom plasma ddPCR detects T790M further strengthens the utility of this technology, although a repeat biopsy would still be needed in patients with uninformative plasma ddPCR due to limitations with respect to assay sensitivity.

This study also examined the potential of the quantitative nature of ddPCR-based plasma genotyping to allow for the early prediction of treatment response. Distinct patterns of change in mutant allele copy number were observed as early as 2 weeks after treatment and were similar to those reported in other tumor types.19,20 We hypothesize that these distinct patterns of change in this study will correlate with specific patterns of radiographic response and emergence of acquired resistance and plan to report these data once mature. The observed differences in treatment discontinuation rates observed in this study comparing patients with complete resolution of detectable mutant cfDNA with those with incomplete resolution support this hypothesis. The use of this technology to monitor disease status in real time has potential utility for both routine clinical care, as well as use as an integrated biomarker in early-phase clinical trials.10

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