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Live Notes, Real Time Conference Coverage 2020 AACR Virtual Meeting April 27, 2020 Minisymposium on Drugging Undrugged Cancer Targets 1:30 pm – 5:00 pm

SESSION VMS.ET01.01 – Drugging Undrugged Cancer Targets

April 27, 2020, 1:30 PM – 3:30 PM
Virtual Meeting: All Session Times Are U.S. EDT

Session Type
Virtual Minisymposium
Track(s)
Experimental and Molecular Therapeutics,Drug Development
18 Presentations
1:30 PM – 1:30 PM
– ChairpersonPeter C. Lucas. University of Pittsburgh School of Medicine, Pittsburgh, PA

1:30 PM – 1:30 PM
– ChairpersonJohn S. Lazo. University of Virginia, Charlottesville, VA

1:30 PM – 1:35 PM
– IntroductionPeter C. Lucas. University of Pittsburgh School of Medicine, Pittsburgh, PA

1:35 PM – 1:45 PM
3398 – PTPN22 is a systemic target for augmenting antitumor immunityWon Jin Ho, Jianping Lin, Ludmila Danilova, Zaw Phyo, Soren Charmsaz, Aditya Mohan, Todd Armstrong, Ben H. Park, Elana J. Fertig, Zhong-Yin Zhang, Elizabeth M. Jaffee. Johns Hopkins Sidney Kimmel Comp. Cancer Center, Baltimore, MD, Purdue University, Baltimore, MD, Johns Hopkins Sidney Kimmel Comp. Cancer Center, Baltimore, MD, Vanderbilt University Medical Center, Baltimore, MD

Abstract: Remarkable progress in cancer immunology has revolutionized cancer therapy. The majority of patients, however, do not respond to immunotherapeutic options, warranting the ongoing search for better strategies. Leveraging the established role of protein tyrosine phosphatase non-receptor type 22 (PTPN22) in autoimmune diseases, we hypothesized that PTPN22 is a novel target for cancer immunotherapy. PTPN22 is a physiologic regulator of T cell receptor (TCR) signaling acting by dephosphorylating activating tyrosine residues in Lck and Zap70. We first confirmed the relevance of PTPN22 expression by exploring its expression in multiple human cancer types using The Cancer Genome Atlas (TCGA). PTPN22 expression positively correlated with T cell and M1 macrophage gene signatures and immune regulatory genes, especially inflamed tumor types. Next, we directly investigated the role of PTPN22 in antitumor immunity by comparing in vivo tumor characteristics in wild-type (WT) and PTPN22 knockout (KO) mice. Consistent with our hypothesis, PTPN22 KO mice resisted MC38 and EG7 tumors significantly compared with WT. Mass cytometry (CyTOF) profiling of the immune tumor microenvironment demonstrated that MC38 tumors in PTPN22 KO mice were infiltrated with greater numbers of T cells, particularly CD8+ T cells expressing granzyme B and PD1. To further delineate the effects of PTPN22 KO on TCR signaling, we established an optimized CyTOF panel of 9 phosphorylation sites involved in the TCR signaling pathway, including two enzymatic substrates of PTPN22 (Lck Y394 and Zap70 Y493) and 15 immune subtyping markers. CyTOF phospho-profiling of CD8 T cells from tumor-bearing mouse spleens and the peripheral blood of immunotherapy-naïve cancer patients showed that the phosphorylated state of Zap70 Y493 correlated strongly with granzyme B expression. Furthermore, phospho-profiling of tumor-infiltrating CD8+ T cells (a measure of T cell activation) revealed the highest TCR-pathway phosphorylation levels in memory CD8+ T cells that express PD1. The difference in phosphorylation levels between WT and PTPN22 KO was most pronounced for Lck Y394. Based on these findings, we then hypothesized that PD1 inhibition will further enhance the antitumor immune responses promoted by the lack of PTPN22. Indeed, PTPN22 KO mice bearing MC38 and EG7 tumors responded more significantly to anti-PD1 therapy when compared with tumor-bearing WT mice. Finally, we treated WT tumor bearing mice with two different small molecule inhibitors of PTPN22, one previously published compound, LTV1, and one novel compound, L1 (discovered through structure based synthesis). While both inhibitors phenocopied the PTPN22 KO mice in resisting MC38 tumor growth, L1 treatment gave an immune profile that resembled what was observed in tumor-bearing PTPN22 KO mice. Taken together, our results demonstrate that PTPN22 is a novel systemic target for augmenting antitumor immunity.

  • can they leverage autoimmune data to look at new targets for checkpoint inhibition; we have a long way to go in immunooncology as only less than 30-40% of cancer types respond
  • using Cancer Genome Atlas PTPN22 is associated with autoimmune disorders
  • PTPN22 KO increases many immune cells; macrophages t-cells and when KO in tumors get more t cell infiltrate
  • PTP KO enhances t cell response, and may be driving t cells to exhaustion
  • made a inhibitor or PTPN22; antitumor phenotype when given inhibitor was like KO mice; a PDL1 inhibitor worked in KO mice
  • PTPN22 only in select hematopoetic cells

1:45 PM – 1:50 PM
– Discussion

1:50 PM – 2:00 PM
3399 – Preclinical evaluation of eFT226, a potent and selective eIF4A inhibitor with anti-tumor activity in FGFR1,2 and HER2 driven cancers. Peggy A. Thompson, Nathan P. Young, Adina Gerson-Gurwitz, Boreth Eam, Vikas Goel, Craig R. Stumpf, Joan Chen, Gregory S. Parker, Sarah Fish, Maria Barrera, Eric Sung, Jocelyn Staunton, Gary G. Chiang, Kevin R. Webster. eFFECTOR Therapeutics, San Diego, CA @RuggeroDavide

Abstract: Mutations or amplifications affecting receptor tyrosine kinases (RTKs) activate the RAS/MAPK and PI3K/AKT signaling pathways thereby promoting cancer cell proliferation and survival. Oncoprotein expression is tightly controlled at the level of mRNA translation and is regulated by the eukaryotic translation initiation factor 4F (eIF4F) complex consisting of eIF4A, eIF4E, and eIF4G. eIF4A functions to catalyze the unwinding of secondary structure in the 5’-untranslated region (5’-UTR) of mRNA facilitating ribosome scanning and translation initiation. The activation of oncogenic signaling pathways, including RAS and PI3K, facilitate formation of eIF4F and enhance eIF4A activity promoting the translation of oncogenes with highly structured 5’-UTRs that are required for tumor cell proliferation, survival and metastasis. eFT226 is a selective eIF4A inhibitor that converts eIF4A into a sequence specific translational repressor by increasing the affinity between eIF4A and 5’-UTR polypurine motifs leading to selective downregulation of mRNA translation. The polypurine element is highly enriched in the 5’-UTR of eFT226 target genes, many of which are known oncogenic drivers, including FGFR1,2 and HER2, enabling eFT226 to selectively inhibit dysregulated oncogene expression. Formation of a ternary complex [eIF4A-eFT226-mRNA] blocks ribosome scanning along the 5’-UTR leading to dose dependent inhibition of RTK protein expression. The 5’-UTR sequence dependency of eFT226 translational inhibition was evaluated in cell-based reporter assays demonstrating 10-45-fold greater sensitivity for reporter constructs containing an RTK 5’-UTR compared to a control. In solid tumor cell lines driven by alterations in FGFR1, FGFR2 or HER2, downregulation of RTK expression by eFT226 resulted in decreased MAPK and AKT signaling, potent inhibition of cell proliferation and an induction of apoptosis suggesting that eFT226 could be effective in treating tumor types dependent on these oncogenic drivers. Solid tumor xenograft models harboring FGFR1,2 or HER2 amplifications treated with eFT226 resulted in significant in vivo tumor growth inhibition and regression at well tolerated doses in breast, non-small cell lung and colorectal cancer models. Treatment with eFT226 also decreased RTK protein levels supporting the potential to use these eFT226 target genes as pharmacodynamic markers of target engagement. Further evaluation of predictive markers of sensitivity or resistance showed that RTK tumor models with mTOR mediated activation of eIF4A are most sensitive to eFT226. The association of eFT226 activity in RTK tumor models with mTOR pathway activation provides a means to further enrich for sensitive patient subsets during clinical development. Clinical trials with eFT226 in patients with solid tumor malignancies have initiated.
  • ternary complex formed blocks transcription selectively downregulating RTKs
  • drug binds in 5′ UTR and inhibits translation
  • RTKs activate eIF4 and are also transcribed through them so inhibition destroys this loop;  also with KRAS too
  • main antitumor activity are by an apoptotic mechanisms; refractory tumors are not sensitive to drug induced apoptosis
  • drug inhibits FGFR2 in colorectal cancer
  • drug also effective in HER2+ tumors
  • mTOR mediated eIF4 inhibited by drug
  • they get prolonged antitumor activity after washout of drug because forms this tight terniary complex

2:00 PM – 2:05 PM
– Discussion

2:05 PM – 2:15 PM
3400 – Adenosine receptor antagonists exhibit potent and selective off-target killing of FOXA1-high cancers: Steven M. Corsello, Ryan D. Spangler, Ranad Humeidi, Caitlin N. Harrington, Rohith T. Nagari, Ritu Singh, Vickie Wang, Mustafa Kocak, Jordan Rossen, Amael Madec, Nancy Dumont, Todd R. Golub. Dana-Farber Cancer Institute, Boston, MA, Broad Institute of MIT and Harvard, Cambridge, MA @corsellos

Abstract: Drugs targeting adenosine receptors were originally developed for the treatment of Parkinson’s disease and are now being tested in immuno-oncology clinical trials in combination with checkpoint inhibitors. We recently reported the killing activity of 4,518 drugs against 578 diverse cancer cell lines determined using the PRISM molecular barcoding approach. Surprisingly, three established adenosine receptor antagonists (CGS-15943, MRS-1220, and SCH-58261) showed potent and selective killing of FOXA1-high cancer cell lines without the need for immune cells. FOXA1 is a lineage-restricted transcription factor in luminal breast cancer, hepatocellular carcinoma, and prostate cancer without known small molecule inhibitors. We find that cytotoxic activity is limited to adenosine antagonists with a three-member aromatic core bound to a furan group, thus indicating a potential off-target mechanism of action. To identify genomic modulators of drug response, we performed genome-wide CRISPR/Cas9 knockout modifier screens. Killing by CGS-15943 and MRS-1220 was rescued by knockout of the aryl hydrocarbon receptor (AHR) and its nuclear partner ARNT. In confirmatory studies, knockout of AHR completely rescued killing by CGS-15943 in multiple cell types. Co-treatment with an AHR small molecule antagonist also rescued cell viability. Knockout of adenosine receptors did not alter drug response. Given that AHR is a known transcriptional regulator, we performed global mRNA sequencing to assess transcriptional changes induced by CGS-15943. The top two genes induced were the p450 enzymes CYP1A1 and CYP1B1. To determine sufficiency, we overexpressed CYP1A1 in a resistant cell line. Ectopic CYP1A1 expression sensitized to CGS-15943-mediated killing. Mass spectrometry revealed covalent trapping of a reactive metabolite by glutathione and potassium cyanide following in vitro incubation with liver microsomes. In addition, treatment of breast cancer cells with CGS-15943 for 24 hours resulted in increased γ-H2AX phosphorylation by western blot, indicative of DNA double stranded breaks. In summary, we identified off-target anti-cancer activity of multiple established adenosine receptor antagonists mediated by activation of AHR. Future studies will evaluate the functional contribution of FOXA1 and activity in vivo. Starting from a phenotypic screening hit, we leverage functional genomics to unlock the underlying mechanism of action. This project will pave the way for developing more effective therapies for biomarker-selected cancers, with potential to improve the care of patients with liver, breast, and prostate cancer.

  • developed a chemical library of over 6000 compounds (QC’d) to determine drugs that have antitumor effects
  • used a PRISM barcoded library to make cell lines to screen genotype-phenotype screens
  • for nononcology drugs fourteen drugs had activity in the PRISM assay
  • FOXA1 transcription factor high cancer cells seemed to be inhibited best with adenosine receptor inhibitor found in PRISM assay

2:15 PM – 2:20 PM
– Discussion

2:20 PM – 2:30 PM
3401 – Targeting lysosomal homeostasis in ovarian cancer through drug repurposing: Stefano Marastoni, Aleksandra Pesic, Sree Narayanan Nair, Zhu Juan Li, Ali Madani, Benjamin Haibe-Kains, Bradly G. Wouters, Anthony Joshua. University Health Network, Toronto, ON, Canada, Janssen Inc, Toronto, ON, Canada, The Kinghorn Cancer Centre, Sydney, Australia

Background: Drug repurposing has become increasingly attractive as it avoids the long processes and costs associated with drug discovery. Itraconazole (Itra) is a broad-spectrum anti-fungal agent which has an established broad spectrum of activity in human cell lines including cholesterol antagonism and inhibition of Hedgehog and mTOR pathways. Many in vitro, in vivo and clinical studies have suggested anti-proliferative activity both alone and in combination with other chemotherapeutic agents, in particular in ovarian cancer. This study is aimed at supporting the therapeutic potential of Itra and discovering and repurposing new drugs that can increase Itra anticancer activity as well as identifying new targets in the treatment of ovarian cancer.
Methods: We tested a panel of 32 ovarian cancer cell lines with different doses of Itra and identified a subset of cells which showed significant sensitivity to the drug. To identify genetic vulnerabilities and find new therapeutic targets to combine with Itra, we performed a whole genome sensitivity CRISPR screen in 2 cell lines (TOV1946 and OVCAR5) treated with non-toxic (IC10) concentrations of Itra.
Results: Pathway analysis on the top hits from both the screens showed a significant involvement of lysosomal compartments, and in particular dynamics between trans Golgi network and late endosomes/lysosomes, pathways that are affected by the autophagy inhibitor Chloroquine (CQ). We subsequently demonstrated that the combination of Itra and CQ had a synergistic effect in many ovarian cancer cell lines, even in those resistant to Itra. Further, genetic and pharmacological manipulation of autophagy indicated that upstream inhibition of autophagy is not a key mediator of the Itra/CQ mechanism of action. However, combination of Itra with other lysosomotropic agents (Concanamycin A, Bafilomycin A and Tamoxifen) displayed overlapping activity with Itra/CQ, supporting the lysosomal involvement in sensitizing cells to Itra resulted from the CRISPR screens. Analysis of lysosomal pattern and function showed a combined effect of Itra and CQ in targeting lysosomes and neutralizing their activity.
Conclusion: We identified two FDA approved drugs – CQ and Tamoxifen – that can be used in combination with Itra and exert a potent anti-tumor effect in ovarian cancer by affecting lyosomal function and suggesting a likely dependency of these cells on lysosomal biology. Further studies are in progress.

  • repurposing itraconozole in ovarian cancer potential mechanism of action is pleitropic
  • increasing doses of chloroquine caused OVCA cell death by accumulating in Golgi

2:30 PM – 2:35 PM
– Discussion

2:35 PM – 2:45 PM
3402 – BCAT1 as a druggable target in immuno-oncologyAdonia E. Papathanassiu, Francesca Lodi, Hagar Elkafrawy, Michelangelo Certo, Hong Vu, Jeong Hun Ko, Jacques Behmoaras, Claudio Mauro, Diether Lambrechts. Ergon Pharmaceuticals, Washington, DC, VIB Cancer Centre-KULeuven, Leuven, Belgium, Alexandria University, Alexandria, Egypt, University of Birmingham, Birmingham, United Kingdom, Ergon Pharmaceuticals, Washington, DC, Imperial College London, London, United Kingdom

2:45 PM – 2:50 PM
– Discussion

2:50 PM – 3:00 PM
3403 – Drugging the undruggable: Lessons learned from protein phosphatase 2A: Derek Taylor, Goutham Narla. Case Western Reserve University, Cleveland, OH, University of Michigan, Ann Arbor, MI @gouthamnarla

Abstract: Protein phosphatase 2A (PP2A) is a key tumor suppressor responsible for the dephosphorylation of many oncogenic signaling pathways. The PP2A holoenzyme is comprised of a scaffolding subunit (A), which serves as the structural platform for the catalytic subunit (C) and for an array of regulatory subunits (B) to assemble. Impairment of PP2A is essential for the pathogenesis of many diseases including cancer. In cancer, PP2A is inactivated through a variety of mechanisms including somatic mutation of the Aαsubunit. Our studies show that the most recurrent Aαmutation, P179R, results in an altered protein conformation which prevents the catalytic subunit from binding. Additionally, correcting this mutation, by expressing wild type PP2A Aαin cell lines harboring the P179R mutation, causes a reduction in tumor growth and metastasis. Given its central role in human disease pathogenesis, many strategies have been developed to therapeutically target PP2A.Our lab developed a series of small molecules activators of protein phosphatase 2A. One of our more advanced analogs in this series, DT-061, drives dephosphorylation and degradation of select pathogenic substrates of PP2A such as c-MYC in cellular and in vivo systems. Additionally, we have demonstrated the phosphomimetics of MYC that prevent PP2A mediated dephosphorylation and degradation markedly reduce the anti-tumorigenic activity of this series of PP2A activators further validating the target-substrate specificity of this approach. Specific mutations in the site of drug interaction or overexpression of the DNA tumor virus small T antigen which has been shown to specifically bind to and inactivate PP2A abrogate the in vivo activity of this small molecule series further validating the PP2A specificity of this approach. Importantly, treatment with DT-061 results in tumor growth inhibition in an array of in vivocancer models and marked regressions in combination with MEKi and PARPi.To further define the mechanism of action of this small molecule series, we have used cryo-electron microscopy (cryo-EM) to visualize directly theinteraction between DT-061 and a PP2A heterotrimeric complex. We have identified molecular interactions between DT-061 and all three PP2A subunits that prevent dissociation of the active enzyme through the marked prolongation of the kOFF of the native complex. Furthermore, we demonstrate that DT-061 specifically stabilizes the B56α-PP2A holoenzyme in a fully assembled, active state to dephosphorylate oncogenic targets such as c-MYC in both cellular and in vivo systems. This 3.6 Å structure identifies dynamic molecular interactions between the three distinct PP2A subunits and highlight the inherent mechanisms of PP2A complex assembly and disassembly in both cell free and cellular systems. Thus, our findings provide fundamental insights into PP2A complex assembly and regulation, identify a unique interfacial stabilizing mode of action for the therapeutic targeting of previously undruggable proteins, and aid in the development of phosphatase-based therapeutics tailored against disease specific phosphor-protein targets. The marriage of multidisciplinary scientific practices has allowed us to present here a previously unrecognized therapeutic strategy of complex stabilization for the activation of endogenous disease combating enzymes.

  • Reactivating PP2A; dephosphorylation of proteins (serine/threonine phosphatases); regulates multiple processes in the cell
  • SV40T has an antigen that inactivates PP2A; recurrent mutations in high grade endometrial cancers
  • P179R mutation promotes uterine tumor formation (also in a distal tubule ligation model)
  • project started in a phenotypic screen that tricyclic antidepressants could have an off target which was phosphatase activators (uncoupling GPCR from anticancer activity)
  • small T antigen block the activity of these small molecule activators;
  • acts as a molecular glue to bring the activators with a heterotrimer of phosphatases
  • so their small molecule activators effective in triple negative breast cancers;  one of targets of PP2A is MYC
  • question: have not yet seen resistance to these compounds but are currently looking at this

 

3:00 PM – 3:05 PM
– Discussion

3:05 PM – 3:15 PM
3404 – Inhibition of BCL10-MALT1 interaction to treat diffuse large B-cell lymphomaH: eejae Kang, Dong Hu, Marcelo Murai, Ahmed Mady, Bill Chen, Zaneta Nikolovska-Coleska, Linda M. McAllister-Lucas, Peter C. Lucas. University of Pittsburgh School of Medicine, Pittsburgh, PA, Merck, Kenilworth, NJ, University of Michigan School of Medicine, Ann Arbor, MI, University of Pittsburgh School of Medicine, Pittsburgh, PA, University of Michigan School of Medicine, Ann Arbor, MI, UPMC Children’s Hospital, Pittsburgh, PA

Abstract: The CARMA1/BCL10/MALT1 (CBM) signaling complex mediates antigen receptor-induced activation of NF-kB in lymphocytes to support normal adaptive immunity. As the effector protein of the complex, MALT1 exhibits two activities: protease and scaffolding activities. Gain-of-function mutations in the CARMA1 moiety or its upstream regulators trigger antigen-independent assembly of oligomeric CBM complexes, leading to constitutive activation of MALT1, unregulated NF-kB activity, and development of Activated B-Cell subtype of Diffuse Large B-Cell Lymphoma (ABC-DLBCL). Existing MALT1 inhibitors block only MALT1 protease activity, causing incomplete and unbalanced inhibition of MALT1, and have the potential for inducing autoimmune side effects. Since MALT1 is recruited to the CBM complex via its interaction with BCL10, we sought to identify inhibitors of BCL10-MALT1 interaction in order to target both the protease and scaffolding activities of MALT1 to treat ABC-DLBCL.
Our previous work suggested that an antibody-epitope-like interface governs the interaction between BCL10 and MALT1, so that a therapeutic opportunity exists for developing a small molecule inhibitor of the interaction to terminate inappropriate CBM activity. Using co-immunoprecipitation studies, a mammalian two-hybrid system, and surface plasmon resonance (SPR), we confirmed that BCL10 residues 107-119 and the tandem Ig-like domains of MALT1 are critical for this interaction. We then performed a structure-guided in silico screen of 3 million compounds, based on a computational model of the BCL10-MALT1 interaction interface, to identify compounds with potential for disrupting the interaction.
Compound 1 from the initial screening hits showed dose-responsive inhibition of BCL10-MALT1 interaction in both SPR and ELISA-based assays. Functionally, Compound 1 inhibits both MALT1 protease and scaffolding activities in Jurkat T cells, as demonstrated by its inhibition of CD3/CD28-induced RelB and N4BP1 cleavage, and inhibition of IKK phosphorylation, respectively. Compound 1 also blocks IL-2 transcription and IL-2 secretion by PMA/ionomycin-treated Jurkat T cells, as well as constitutive CBM-dependent secretion of IL-6 and IL-10 by ABC-DLBCL cells. Accordingly, Compound 1 selectively suppresses the growth of ABC-DLBCL cell lines, but does not affect the growth of MALT1-independent GCB-DLBCL cell lines.
In conclusion, we have identified an early-stage small molecule compound that inhibits the BCL10-MALT1 interaction, MALT1 protease and scaffolding activities, downstream CBM-dependent signaling, and ABC-DLBCL cell growth. Structure-guided modification of this lead compound is underway to further develop a new class of protein-protein interaction inhibitors that could provide more efficacious blockade of MALT1, while offering protection from undesirable autoimmune side effects in the treatment of this aggressive form of lymphoma.

3:15 PM – 3:20 PM
– Discussion

3:20 PM – 3:30 PM
– Closing RemarksJohn S. Lazo. University of Virginia, Charlottesville, VA

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New Type of Killer T-Cell

Reporter: Irina Robu, PhD

Scientists at Cardiff University have revealed a new type of killer T-cell which offers hope of a “one-size-fits-all” cancer therapy. Cancer-targeting via MR1-restricted T-cells is a thrilling new frontier, it increases the prospect of a ‘one-size-fits-all’ cancer treatment; a single type of T-cell that could be proficient of destroying numerous different types of cancers across the population.

T-cell therapies for cancer anywhere immune cells are removed, modified and returned to the patient’s blood to seek and destroy cancer cells – are the latest paradigm in cancer treatments. The most extensively-used therapy, known as CAR-T (Chimeric Antigen Receptor T-cell therapy) encompasses genetic modification of patient’s autologous T-cells to express a CAR specific for a tumor antigen, subsequent by ex vivo cell expansion and re-infusion back to the patient. The therapy is personalized to each patient, but targets only a few types of cancers.

Currently, Cardiff academics discovered T-cells equipped with a new type of T-cell receptor (TCR) which recognizes and kills most human cancer types, while ignoring healthy cells. This new TCR distinguishes when a molecule is present on the surface of a wide range of cancer cells and is able to distinguish between cancerous and healthy cells. Normal T-cells scans the surface of other cells to find anomalies and eliminate cancerous cells, yet ignores cells that contain only normal proteins.

The researchers at Cardiff was published in Nature Immunology, labels a unique TCR that can identify various types of cancer via a single HLA-like molecule called MR1 which varies in the human population. HLA differs extensively between individuals, which has previously prevented scientists from creating a single T-cell-based treatment that targets most cancers in all people. To investigate the therapeutic potential of these cells in vivo, the investigators injected T-cells able to identify MR1 into mice bearing human cancer and with a human immune system.

The Cardiff group were able to demonstrate that T-cells of melanoma patients modified to express this new TCR could destroy not only the patient’s own cancer cells, but also other patients’ cancer cells in the laboratory, irrespective of the patient’s HLA type. Experiments are under way to regulate the exact molecular mechanism by which the new TCR differentiates between healthy cells and cancer.

Source

https://www.eurekalert.org/pub_releases/2020-01/cu-don012020.php

 

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Moderna Therapeutics Deal with Merck: Are Personalized Vaccines here?

Curator & Reporter: Stephen J. Williams, Ph.D.

Take aways:

  • RNA based vaccines are a cost-effective method of developing and manufacturing a personalized cancer vaccine strategy; traditional vaccine methodology has not been met with much success as a cancer therapeutic
  • Most of the older RNA vaccine technology depended on isolated dendritic cells or T cell populations and ex-vivo treatment with RNA vaccine, HOWEVER, Moderna has developed a technology that circumvents the need for ex-vivo vaccination
  • There are multiple companies involved in this new RNA strategy (Moderna, Caperna {now Moderna}, CureVac, Biontech)

From BusinessWire at http://www.businesswire.com/news/home/20160629005446/en/Merck-Moderna-Announce-Strategic-Collaboration-Advance-mRNA-Based

Merck and Moderna Announce Strategic Collaboration to Advance Novel mRNA-Based Personalized Cancer Vaccines with KEYTRUDA®(pembrolizumab) for the Treatment of Multiple Types of Cancer

Collaboration Combines Merck’s Leadership in Immuno-Oncology with Moderna’s Pioneering mRNA Vaccine Technology and Rapid Cycle Time, Small-Batch GMP Manufacturing Capabilities

KENILWORTH, N.J. & CAMBRIDGE, Mass.–(BUSINESS WIRE)–Merck (NYSE:MRK), known as MSD outside the United States and Canada, and Moderna Therapeutics today announced a strategic collaboration and license agreement to develop and commercialize novel messenger RNA (mRNA)-based personalized cancer vaccines. The collaboration will combine Merck’s established leadership in immuno-oncology with Moderna’s pioneering mRNA vaccine technology and GMP manufacturing capabilities to advance individually tailored cancer vaccines for patients across a spectrum of cancers.

“Combining immunotherapy with vaccine technology may be a new path toward improving outcomes for patients”

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Moderna and Merck will develop personalized cancer vaccines that utilize Moderna’s mRNA vaccine technology to encode a patient’s specific neoantigens, unique mutations present in that specific patient’s tumor. When injected into a patient, the vaccine will be designed to elicit a specific immune response that will recognize and destroy cancer cells. The companies believe that the mRNA-based personalized cancer vaccines’ ability to specifically activate an individual patient’s immune system has the potential to be synergistic with checkpoint inhibitor therapies, including Merck’s anti-PD-1 therapy, KEYTRUDA® (pembrolizumab). In addition, Moderna has developed a rapid cycle time, small-batch manufacturing technique that will uniquely allow the company to supply vaccines tailored to individual patients within weeks.

Under the terms of the agreement, Merck will make an upfront cash payment to Moderna of $200 million, which Moderna will use to lead all research and development efforts through proof of concept. The development program will entail multiple studies in several types of cancer and include the evaluation of mRNA-based personalized cancer vaccines in combination with Merck’s KEYTRUDA® (pembrolizumab). Moderna will also utilize the upfront payment to fund a portion of the build-out of a GMP manufacturing facility in suburban Boston for the purpose of personalized cancer vaccine manufacturing.

Following human proof of concept studies, Merck has the right to elect to make an additional undisclosed payment to Moderna. If exercised, the two companies will then equally share cost and profits under a worldwide collaboration for the development of personalized cancer vaccines. Moderna will have the right to elect to co-promote the personalized cancer vaccines in the U.S. The agreement entails exclusivity around combinations with KEYTRUDA. Moderna and Merck will each have the ability to combine mRNA-based personalized cancer vaccines with other (non-PD-1) agents.

Combining immunotherapy with vaccine technology may be a new path toward improving outcomes for patients,” said Dr. Roger Perlmutter, President, Merck Research Laboratories. “While the area of personalized cancer vaccine research has faced challenges in the past, there have been many recent advances, and we believe that working with Moderna to combine an immuno-oncology approach, using KEYTRUDA, with mRNA-based personalized cancer vaccines may have the potential to transform the treatment of cancer.”

“Our team has made significant progress since beginning our work in personalized cancer vaccines just last year. Through this collaboration with Merck, we are now well-positioned to accelerate research and development with a goal of entering the clinic in 2017, as well as to apply our unique GMP manufacturing capabilities to support the rapid production of these highly individualized vaccines,” said Stéphane Bancel, chief executive officer of Moderna. “We value our continued collaboration with Merck, and we look forward to working together to harness the potential of personalized cancer vaccines and immuno-oncology to bring a new treatment paradigm to patients.”

Merck and Moderna have an existing collaboration and license agreement focused on the discovery and development of mRNA-based infectious disease vaccines and passive immunity treatments. Moderna is also advancing its own pipeline of infectious disease vaccine candidates and currently has two phase 1 studies underway in Europe and the U.S.

About Moderna Therapeutics

Moderna is a clinical stage pioneer of messenger RNA Therapeutics™, an entirely new in vivo drug technology that produces human proteins, antibodies and entirely novel protein constructs inside patient cells, which are in turn secreted or active intracellularly. This breakthrough platform addresses currently undruggable targets and offers a potentially superior alternative to existing drug modalities for a wide range of diseases and conditions. Moderna is developing and plans to commercialize its innovative mRNA drugs through its own ventures and its strategic relationships with established pharmaceutical and biotech companies. Its current ventures are:

  • Onkaido, focused on oncology,
  • Valera, focused on infectious diseases,
  • Elpidera, focused on rare diseases, and
  • Caperna, focused on personalized cancer vaccines.

Cambridge-based Moderna is privately held and currently has strategic agreements with AstraZeneca, Alexion Pharmaceuticals and Merck. To learn more, visit www.modernatx.com.

From the Moderna Therapeutics Website

Our mRNA Platform

At Moderna, we are pioneering the development of a new class of drugs made of messenger RNA (mRNA). This novel drug platform builds on the discovery that modified mRNA can direct the body’s cellular machinery to produce nearly any protein of interest, from native proteins to antibodies and other entirely novel protein constructs that can have therapeutic activity inside and outside of cells.

Our efforts are helping Moderna and the industry to flatten the mRNA learning curve across the full breadth of competencies needed to drive the platform forward, including chemistry, mRNA biology, formulation, process development, automation and high-throughput production, quality, and Good Manufacturing Practice (GMP) manufacturing.

Drug Modalities

Building from our mRNA core expression platform, we have created a new scale of drug discovery and development that enables a series of new drug modalities. Each modality represents a distinct approach to using the mRNA platform to encode proteins that achieve a therapeutic benefit, enabling us to develop numerous drug candidates across a wide array of therapeutic areas.

Vaccines

Vaccines are substances that teach the immune system to rapidly recognize and destroy invading pathogens such as bacteria or viruses, preparing the body’s adaptive immunity for future exposure to the pathogen. Historically, vaccines have introduced immune-activating markers from pathogens into the body. Conversely, Moderna is developing mRNA-based vaccines that enable the body to produce and present immunogenic proteins to the immune system.

Moderna is also developing mRNA-based personalized cancer vaccines to prime the immune system to recognize cancer cells and mount a strong, tailored response to each individual patient’s cancer. Moderna’s technology allows for a rapid turn-around time in production of these unique mRNA vaccines.

Intracellular/Transmembrane

Many diseases are caused by defects in proteins that function inside cells. Existing methods of protein-based therapy do not allow for proteins to reach the intracellular space, and as such are unable to replace the defective, disease-causing proteins within cells. Moderna’s platform allows for the development of mRNA therapies that can stimulate production of intracellular proteins as well as transmembrane proteins. This could potentially lead to a novel approach to treating a vast array of rare genetic and other diseases caused by intracellular protein defects.

Intratumoral

Many targets for the treatment of cancer have been identified but their therapeutic potential has been limited by either the inability to access these targets, or by systemic toxicities. Moderna’s platform allows for localized expression of therapeutic proteins within the tumor microenvironment.

Secreted antibodies

Antibodies are secreted proteins that bind to and inhibit specific targets. Moderna’s platform has the potential to stimulate the body’s own cells to produce specific antibodies that can bind to cellular targets.

Secreted proteins

Proteins are large, complex molecules that have many critical functions both inside and outside of cells. Moderna’s platform stimulates cells to produce and secrete proteins that can have a therapeutic benefit through systemic exposure.

Moderna is comprised of four smaller companies, the following three are involved in their personalized immunotherapy and cancer vaccine strategy

Caperna LLC

Caperna

Caperna LLC is the fourth Moderna venture company — formed, funded and wholly-owned by Moderna — and focused exclusively on the advancement of personalized cancer vaccines.

Caperna will apply Moderna’s mRNA vaccine technology to the field of cancer vaccines, building on advances in recent years in cancer immunotherapy. Utilizing Moderna’s demonstrated engineering and process capability to synthesize over 1,000 unique novel mRNA’s per month in Moderna’s, automated, in-house productions systems. This provides the basis for a vision of rapid turnaround times that will allow Caperna’s personalized cancer vaccine, customized after tumor biopsy and sequencing to code for specific neoantigens in patients’ tumors, to be used to treat patients with aggressive tumors and high unmet need (rather than those with less aggressive tumors which can’t wait for prolonged turnaround times). Caperna will develop its personalized cancer vaccines in combination with checkpoint inhibitors that unleash the immune system and other cancer immunotherapies.

Corporate Facts

  • President: Tal Zaks, M.D., Ph.D.
  • Head of Research: Nicholas Valiante, Ph.D.
  • Head of Operations: Ted Ashburn, M.D., Ph.D.
  • Headquarters: 500 Technology Square, Cambridge, Mass.
  • Phone: 617-714-6500
  • Website: Caperna.com

 

Onkaido

Onkaido

Onkaido Therapeutics is the first Moderna venture company – formed, funded and wholly-owned by Moderna. Onkaido is focused exclusively on developing mRNA-based oncology treatments for currently undruggable targets or as a superior alternative to existing drug modalities. Onkaido is leveraging all of the tools and modalities developed at Moderna, with plans to rapidly turn mRNA science into truly novel cancer therapies that can make a real difference for patients.

Onkaido is currently focused on three therapeutic areas of oncology drug discovery and development: immuno-oncology, hepatocellular carcinoma (liver cancer) and myeloid malignancies – with programs investigating multiple targets and therapies simultaneously. Onkaido scientists are also exploring the power of mRNA technology in precision cancer pharmacology – researching areas such as tumor biology, targeting and gene silencing, driving the science toward the delivery of truly personalized cancer treatment.

Corporate Facts

  • President: Stephen Kelsey, M.D.
  • Headquarters: 500 Technology Square, Cambridge, Mass.
  • Phone: 617-714-6500
  • Website: Onkaido.com

 

Valera

Valera

Valera LLC is the second Moderna venture company — formed, funded and wholly-owned by Moderna — and focused exclusively on the advancement of vaccines and therapeutics for the prevention and treatment of viral, bacterial and parasitic infectious diseases.

The vaccines work of Valera builds on a body of preclinical research at Moderna showing the ability of modified mRNA to express viral antigens in vivo and to induce robust immune responses. Valera’s therapeutic passive immunity programs will expand on Moderna’s research using mRNA to express antibodies that bind to viral and other targets. The robust data from these programs across a range of preclinical infectious disease models, together with the inherent, rapid turn-around time in creating novel mRNA constructs, provide Valera with a potentially powerful and versatile new platform for the creation of a broad array of vaccines and passive immunity therapies.

Corporate Facts

  • President: Michael Watson, MB ChB, MRCP, AFPM
  • Chief Scientific OfficerGiuseppe Ciaramella, Ph.D.
  • Interim Chief Medical OfficerTal Zaks, M.D., Ph.D.
  • Headquarters: 500 Technology Square, Cambridge, Mass.
  • Phone: 617-714-6500
  • Website: Valeratx.com

And from http://endpts.com/neoantigens-beckon-merck-into-a-200m-cancer-collaboration-with-moderna/

Neoantigens beckon Merck into a $200M cancer collaboration with Moderna


Now that Galena has added fresh evidence that first-gen cancer vaccines make for a poor R&D program, Merck is betting $200 million upfront that the next-gen neoantigen approach to personalized cancer vaccines can succeed where all else has failed.

Merck is tying up with the mRNA specialists at Cambridge, MA-based Moderna, which has inked a long lineup of marquee partnerships. The big idea here is that each person’s cancer cells present unique “neoantigens” that can be used to tailor a cancer vaccine for each patient.

That’s a radical idea that has gained considerable steam in recent months, with Gritstone and Neon Therapeutics — paired now with Bristol-Myers on Opdivo — rounding up significant venture cash. Biotech billionaire Patrick Soon-Shiong has also jumped into the game, including it in its growing slate of cancer R&D work in a group of startups.

Moderna says it has already set up a manufacturing system that can be used to create these personalized vaccines in a matter of weeks. And Merck will use the partnership to advance new combination therapies that include its checkpoint inhibitor Keytruda.

The way the deal works, Moderna notes in its statement, is that Merck can step up after it sees some evidence in humans that the tech is working as planned. After human proof-of-concept, if Merck wants to opt in they can pay a significant milestone and then both companies can share the cost on Phase III and commercializations, profiting equally.Moderna CEO Stéphane Bancel says they can jump into the clinic next year.

The deal marks another rare pact by Merck R&D chief Roger Perlmutter, who’s been carefully focused on making Keytruda a foundation franchise that can sustain the company for years to come. While Merck has been a couple of steps behind Bristol-Myers in gaining market share, Perlmutter’s not settling for a second place finish.

“Combining immunotherapy with vaccine technology may be a new path toward improving outcomes for patients,” said Perlmutter, president, Merck Research Laboratories. “While the area of personalized cancer vaccine research has faced challenges in the past, there have been many recent advances, and we believe that working with Moderna to combine an immuno-oncology approach, using KEYTRUDA, with mRNA-based personalized cancer vaccines may have the potential to transform the treatment of cancer.”

From FierceBiotech on failure of Galena’s breast cancer vaccine trial

Galena plummets into microcap territory on Phase III breast cancer vaccine trial halt

Immunother Cancer. 2015; 3: 26.
Published online 2015 Jun 16. doi:  10.1186/s40425-015-0068-y
PMCID: PMC4468959

Self-adjuvanted mRNA vaccination in advanced prostate cancer patients: a first-in-man phase I/IIa study

Klinikum rechts der Isar der Technischen Universität München, Munich, Germany
CureVac GmbH, Paul-Ehrlich-Str. 15, Tuebingen, 72076 Germany
Charité University Hospital Berlin, Berlin, Germany
University Hospital Freiburg, Freiburg, Germany
Universitäty Hospital Essen, Essen, Germany
San Raffaele Scientific Institute, Milan, Italy
University Hospital of the Johannes-Gutenberg-University Mainz, Mainz, Germany
Ortenau Klinikum Offenburg-Gengenbach, Offenburg, Germany
University Hospital Göttingen, Göttingen/University Hospital Mannheim, Mannheim, Germany
University Hospital Schleswig-Holstein Campus Luebeck, Luebeck, Germany
Rippin-Consulting, Solingen, Germany
University Hospital Tuebingen, Tuebingen, Germany
Hubert Kübler, ed.nehcneum-ut.zrl@relbeuK.H.
corresponding authorCorresponding author.
#Contributed equally.

Abstract

Background

CV9103 is a prostate-cancer vaccine containing self-adjuvanted mRNA (RNActive®) encoding the antigens PSA, PSCA, PSMA, and STEAP1. This phase I/IIa study evaluated safety and immunogenicity of CV9103 in patients with advanced castration-resistant prostate-cancer.

Methods

44 Patients received up to 5 intra-dermal vaccinations. Three dose levels of total mRNA were tested in Phase I in cohorts of 3–6 patients to determine a recommended dose. In phase II, 32 additional patients were treated at the recommended dose. The primary endpoint was safety and tolerability, the secondary endpoint was induction of antigen specific immune responses monitored at baseline and at weeks 5, 9 and 17.

Results

The most frequent adverse events were grade 1/2 injection site erythema, injection site reactions, fatigue, pyrexia, chills and influenza-like illness. Possibly treatment related urinary retention occurred in 3 patients. The recommended dose was 1280 μg. A total of 26/33 evaluable patients treated at 1280 μg developed an immune response, directed against multiple antigens in 15 out of 33 patients. One patient showed a confirmed PSA response. In the subgroup of 36 metastatic patients, the Kaplan-Meier estimate of median overall survival was 31.4 months [95 % CI: 21.2; n.a].

Conclusions

The self-adjuvanted RNActive® vaccine CV9103 was well tolerated and immunogenic.

The technology is a versatile, fast and cost-effective platform allowing for creation of vaccines. The follow-up vaccine CV9104 including the additional antigens prostatic acid phosphatase (PAP) and Muc1 is currently being tested in a randomized phase IIb trial to assess the clinical benefit induced by this new vaccination approach.

SOURCE

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4468959/

Other articles in the Open Access Journal on Cancer Vaccines Include:

Cancer Vaccines: Targeting Cancer Genes for Immunotherapy – A Conference by Keystone Symposia on Molecular and Cellular Biology

AACR2016 – Cancer immunotherapy

Aduro Biotech Phase II Pancreatic Cancer Trial CRS-207 plus cancer vaccine GVAX Fails

Cases in Biotech Entrepreneurship: Selective Start Ups in 2016

at #JPM16 – Moderna Therapeutics turns away an extra $200 million: with AstraZeneca (collaboration) & with Merck ($100 million investment)

 

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Targeted Liposome Based Delivery System to Present HLA Class I Antigens to Tumor Cells: Two papers

Reporter: Stephen J. Williams, Ph.D.

 

Abstract

Cell-mediated immunotherapies have potential as stand-alone and adjuvant therapies for cancer. However, most current protocols suffer from one or more of three major issues: cost, safety, or efficacy. Here we present a nanoparticle delivery system that facilitates presentation of an immunogenic measles antigen specifically in cancer cells. The delivery system does not contain viral particles, toxins, or biologically derived material. Treatment with this system facilitates activation of a secondary immune response against cancer cells, bypassing the need to identify tumor-associated antigens or educate the immune system through a primary immune response. The delivery system consists of a stealth liposome displaying a cancer-specific targeting peptide, named H1299.3, on its exterior surface and encapsulating H250, an immunogenic human leukocyte antigen class 1 restricted peptide. This targeted-nanoparticle facilitates presentation of the H250 peptide in major histocompatibility complex class I molecules. Activation is dependent on the targeting peptide, previous antigen exposure, and utilizes a novel autophagy-mediated mechanism to facilitate presentation. Treatment with this liposome results in a significant reduction of tumor growth using an aggressive LLC1 model in vaccinated C57BL/6 mice. These data provide proof-of-principle for a novel cell-mediated immunotherapy that is scalable, contains no biologically derived material, and is an efficacious cancer therapy.

Introduction

Cell-mediated (CM) immunotherapies for cancer treatment are designed to activate the body’s adaptive immune responses against a malignant growth.1,2 Generally, the goal of a CM response is to activate a cytotoxic T-cell response against a tumor to eliminate cancer cells. The principle of these treatments is straightforward, yet current work studying the complexity of the tumor micro-environment2,3 as well as methods that attempt to directly activate T cells against tumor antigens4,5,6 demonstrate the difficulty associated generating an immune response against a tumor.

Several CM cancer immunotherapies exist today. Major examples include PD-1 inhibitors, injection of live virus or viral particles into tumors, and adoptive T-cell therapies.1,6,7,8 However, concerns regarding efficacy, safety, and/or cost have limited the use of many of these treatments. To address these concerns, we sought to develop a novel treatment based on developing a fully synthetic, minimal delivery system that facilitates presentation of human leukocyte antigen (HLA) class I restricted immunogenic peptides specifically on cancer cells without using live virus, viral subunits, or biologically derived material.

Based on these requirements, we developed a liposomal based agent consisting of a neutral, stealth liposome that encapsulates a synthetically manufactured immunogenic HLA class I restricted peptide derived from measles virus.1,2,9 In addition, the liposome has a targeting peptide on the external surface that both specifically accumulates in cancer cells and facilitates presentation of the immunogenic peptide in HLA class I molecules (Figure 1a). Thus, this treatment is designed to generate a secondary CM immune response specifically against the tumor if the patient was previously vaccinated against or infected with measles.

Figure 1

The minimal antigen delivery system consists of three components. (a) PEGylated stealth liposomes are loaded with an immunogenic human leukocyte antigen (HLA) class 1 restricted peptide derived from measles virus, named H250. The surface of the liposome

In this proof-of-concept study, we synthesized a liposome that encapsulates H250,1 an immunogenic HLA class 1 restricted peptide identified from measles hemagglutinin protein. The liposome is designed to specifically internalize in cancer cells by displaying the recently identified targeting peptide H1299.3 on the exterior surface (Figure 1b).10 H1299.3 is a 20mer, cancer-specific targeting peptide that was recently identified by our group. The peptide was identified using a novel phage display technique that allows for selection of cancer-specific targeting peptides that preferentially internalize in cancer cells via a defined mechanism of endocytosis. This peptide was dimerized on a lysine core and is fully functional outside the context of the phage particle. The H1299.3 peptide accumulates specifically in a panel of non-small cell lung cancer (NSCLC) cell lines compared to a normal bronchial epithelial cell control cell line via a clathrin-dependent mechanism of endocytosis. In this study, we demonstrate that H1299.3 facilitates functional presentation of an immunogenic antigen in both major histocompatibility complex (MHC) and HLA class I molecules as indicated by CD8+-specific interferon (IFN)γ secretion. In addition, H1299.3 facilitated presentation utilizes an autophagy-dependent mechanism. Finally, treatment with H1299.3 targeted liposomes containing H250 substantially reduces the growth rate of subcutaneous LLC1 tumors implanted in vaccinated C57BL/6 mice compared to treatment with vehicle control.

Result summarized:

  1. The H1299.3 targeting ligand specifically accumulates in cancer and facilitates HLA class I presentation: H250 is an immunogenic peptide identified from sequencing peptides present in HLA A*0201 molecules following measles infection. identified two donors that were HLA A*02 positive and had previously been vaccinated against measles virus (the human NSCLC cell line, H1993, which we determined to be HLA A*02 positive)
  2. identified three different cancer-specific targeting peptides that internalize into H1993 that have been previously published: H1299.2, H2009.1, and H1299.3. Each of these peptides specifically internalize in NSCLC cell lines compared to normal bronchial epithelial cells
  3. H1299.3 facilitated HLA class I presentation requires autophagy. H1299.3 peptide colocalizes with Lamp-1 which is a marker of both lysosomes and autolysosomes, therefore it was possible autophagy involved and shown that H1299.3 colocalizes with autophagosomes.  Chlorpromazine, which inhibits clathrin coated mediatated endocytosis, decreased the HLA1 presentation of H250.
  4. H1299.3-targeted liposomes encapsulating H250 reduce tumor burden in vivo. Mice were first vaccinated against H250.  The J1299.3 targeted liposome encapsulation H250 reduced tumor growth of LLC1 s.c. xenograpfts  by 50%.
J Transl Med. 2011 Mar 31;9:34. doi: 10.1186/1479-5876-9-34.

Enhanced presentation of MHC class Ia, Ib and class II-restricted peptides encapsulated in biodegradable nanoparticles: a promising strategy for tumor immunotherapy.

Abstract

BACKGROUND:

Many peptide-based cancer vaccines have been tested in clinical trials with a limited success, mostly due to difficulties associated with peptide stability and delivery, resulting in inefficient antigen presentation. Therefore, the development of suitable and efficient vaccine carrier systems remains a major challenge.

METHODS:

To address this issue, we have engineered polylactic-co-glycolic acid (PLGA) nanoparticles incorporating: (i) two MHC class I-restricted clinically-relevant peptides, (ii) a MHC class II-binding peptide, and (iii) a non-classical MHC class I-binding peptide. We formulated the nanoparticles utilizing a double emulsion-solvent evaporation technique and characterized their surface morphology, size, zeta potential and peptide content. We also loaded human and murine dendritic cells (DC) with the peptide-containing nanoparticles and determined their ability to present the encapsulated peptide antigens and to induce tumor-specific cytotoxic T lymphocytes (CTL) in vitro.

RESULTS:

We confirmed that the nanoparticles are not toxic to either mouse or human dendritic cells, and do not have any effect on the DC maturation. We also demonstrated a significantly enhanced presentation of the encapsulated peptides upon internalization of the nanoparticles by DC, and confirmed that the improved peptide presentation is actually associated with more efficient generation of peptide-specific CTL and T helper cell responses.

CONCLUSION:

Encapsulating antigens in PLGA nanoparticles offers unique advantages such as higher efficiency of antigen loading, prolonged presentation of the antigens, prevention of peptide degradation, specific targeting of antigens to antigen presenting cells, improved shelf life of the antigens, and easy scale up for pharmaceutical production. Therefore, these findings are highly significant to the development of synthetic vaccines, and the induction of CTL for adoptive immunotherapy.

[PubMed – indexed for MEDLINE]

Free PMC Article

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Immunotherapy Resistance Rears Its Ugly Head Again: PD-1 Resistant Metastatic Melanoma and More

Curator/Reporter: Stephen J. Williams, Ph.D.

From GenomeWeb

Source: https://www.genomeweb.com/sequencing/immune-gene-mutations-found-immunotherapy-resistant-metastatic-melanoma-patients?utm_source=SilverpopMailing&utm_medium=email&utm_campaign=Daily%20News:%20U%20of%20Texas%20Southwestern%20Medical%20Center%20Licenses%20Exosome%20Tech%20to%20Peregrine%20Pharmaceuticals%20-%2007/14/2016%2011:05:00%20AM

Immune Gene Mutations Found in Immunotherapy-Resistant Metastatic Melanoma Patients

NEW YORK (GenomeWeb) – Researchers from the US and the Netherlands reported in the New England Journal of Medicine that they have identified mutations in immune system-related genes in individuals who initially responded to anti-PD-1 treatment for metastatic melanoma treatment, but relapsed after six months or more.

A team led by investigators at the University of California at Los Angeles, the Jonsson Comprehensive Cancer Center, and the Netherlands Cancer Institute did exome sequencing on tumor samples from four individuals with metastatic melanoma prior to treatment with pembrolizumab (marketed as Keytruda by Merck). The researchers also assessed protein-coding sequences in tumor samples taken after late relapse, comparing the baseline and relapse tumors to search for mutations related to checkpoint blockade therapy resistance.

They uncovered suspicious mutations in three of the four individuals. In one individual, for example, they saw a truncating mutation affecting the beta-2-microglobulin (B2M) gene, which contributes to expression of class I major histocompatibility complex molecules recognized by the immune system’s CD8 T cells. Two more relapse tumors contained loss-of-function mutations to JAK1 or JAK2 — genes coding for interferon-related kinase enzymes.

“The mutations make the tumor resistant to the way the immune system tries to kill it,” first author Jesse Zaretsky, an MD/PhD student in senior author Antoni Ribas’ University of California at Los Angeles lab, told GenomeWeb. For example, he explained, the JAK mutations “are associated with the interferon receptor and make the tumors insensitive to the signals the immune system sends to slow [tumor] growth and kill the cancer.”

While roughly three-quarters of individuals treated with anti-PD-1 therapies show durable treatment responses, acquired resistance can occur, even long after immunotherapy-mediated tumor regression.

“With the approval of PD-1 checkpoint blockade agents for the treatment of patients with melanoma, lung cancer, and other cancers, it is anticipated that cases of late relapse after initial response will increase,” the study’s authors wrote. “Understanding the molecular mechanisms of acquired resistance … may open options for the rational design of salvage combination therapies or preventative interventions and may guide mechanistic biomarker studies for the selection of patients, before the initiation of treatment, who are unlikely to have a response.”

The team started with 78 metastatic melanoma patients who were treated with pembrolizumab at UCLA. Of the 42 individuals who showed an objective response to the checkpoint blockade therapy, 15 eventually experienced disease progression.

From that group of 15 patients, the researchers focused on four patients with late-acquired resistance — six months or more after response to pembrolizumab as a single agent — for whom there was sufficient biopsy material and clinical information available. Each of the patients had been receiving continuous doses of the drug until relapse, which occurred after a mean of nearly 21 months.

When the investigators scrutinized biopsies from the relapse tumors, they saw enhanced PD-L1 expression at the edges of tumors, along with CD8 T cells attempting to infiltrate the tumors. After capturing protein-coding portions of the genome in baseline and relapse tumor samples with Nimblegen exome kits, the team sequenced the exomes to nearly 150-fold average coverage using the Illumina HiSeq 2000.

“We wanted to capture all of the mutations down to low allele frequencies to get a picture of everything that was going on in the tumors, both before they went on the treatment and after [the tumors] came back,” Zaretsky said.

In the two cases marked by new JAK1 or JAK2 mutations at relapse, the team found that 93 percent to nearly 96 percent of baseline tumor mutations persisted in the relapse tumors.

The researchers suspect resistance mutations arose from clonal populations in the metastatic tumors that expanded after anti-PD-1 treatment. From allele frequency patterns in the relapsed tumors with JAK1/2 mutations, for example, they concluded that “tumors resistant to anti-PD-1 are a relatively homogeneous population derived directly from the baseline tumor and that acquisition of the JAK mutations was an early founder event.”

Even so, they didn’t detect burgeoning resistance mutations in the pre-pembrolizumab-treatment tumors, Zaretsky said, perhaps because such alterations were present in very few cells in the baseline tumors.

In cell lines established from the individual with JAK2 loss-of-function mutations at relapse, the team’s NanoString Technologies’ nCounter expression experiments pointed to loss of JAK2 protein expression after treatment progression, along with a dip in interferon gamma activity and diminished production of proteins involved in antigen presentation and T cell activity.

Other articles related to ImmunoOncology in this Open Access Journal include:

Vectorisation Of Immune Checkpoint Inhibitor Antibodies

First Drug in Checkpoint Inhibitor Class of Cancer Immunotherapies has demonstrated Superiority over Standard of care in the treatment of First-line Lung Cancer Patients: Merck’s Keytryda

Durable responses with checkpoint inhibitor

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

 

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Aduro Biotech Phase II Pancreatic Cancer Trial CRS-207 plus cancer vaccine GVAX Fails

Reporter: Stephen J. Williams, Ph.D

From Biospace News

May 16, 2016
By Alex Keown, BioSpace.com Breaking News Staff

BERKELEY, Calif. – Shares of Aduro Biotech (ADRO) have fallen more than 25 percent this morning following news that the company’s Phase II trial for its combination pancreatic cancer drug, CRS-207 did not meet its primary endpoint of survivability.

Aduro said its Eclipse trial of CRS-207 failed to show an improvement in overall survival for patients with pancreatic cancer who had failed at least two prior therapies in the metastatic setting. Median overall survival was 3.8 months for patients treated with the immunotherapy regimen of CRS-207 and the cancer vaccine GVAX pancreas, 5.4 months for patients treated with CRS-207 alone and 4.6 months for patients administered chemotherapy. Aduro said there were no reported safety concerns during the trial and full study findings will be presented at a later date.

Stephen T. Isaacs, chairman, president and chief executive officer of Aduro, called the findings a disappointing and “unexpected outcome.’

“While we are well aware of the very difficult-to-treat nature of late-stage metastatic pancreatic cancer, we are surprised by the divergence of these data from the results of our Phase IIa study. At the same time, we continue to look forward to the interim results later this year from our ongoing Stellar trial, which is evaluating CRS-207 and GVAX Pancreas with and without the anti-PD1 checkpoint inhibitor nivolumab as a second-line therapy for patients with metastatic pancreatic cancer,” Isaacs said in a statement.

For full story please see http://www.biospace.com/News/aduro-biotechs-stock-craters-after-pancreatic/419628/source=TopBreaking

Also from FierceBiotech

UPDATED: Aduro combo fails in a key pancreatic cancer study

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Issues Need to be Resolved With Immuno-Modulatory Therapies: NK cells, mAbs, and adoptive T cells

Curator: Stephen J. Williams, PhD

nihms-618191-f0001NKvaciines

 

 

 

 

 

 

 

 

 

 

 

Immunotherapy. 2014;6(3):309-20. doi: 10.2217/imt.13.175.

Optimizing NKT cell ligands as vaccine adjuvants.

Carreño LJ1Kharkwal SSPorcelli SA.

Author information

Abstract

NKT cells are a subpopulation of T lymphocytes with phenotypic properties of both T and NK cells and a wide range of immune effector properties. In particular, one subset of these cells, known as invariant NKT cells (iNKT cells), has attracted substantial attention because of their ability to be specifically activated by glycolipid antigens presented by a cell surface protein called CD1d. The development of synthetic α-galactosylceramides as a family of powerful glycolipid agonists for iNKT cells has led to approaches for augmenting a wide variety of immune responses, including those involved in vaccination against infections and cancers. Here, we review basic, preclinical and clinical observations supporting approaches to improving immune responses through the use of iNKT cell-activating glycolipids. Results from preclinical animal studies and preliminary clinical studies in humans identify many promising applications for this approach in the development of vaccines and novel immunotherapies.

 

 

Cancer Res. 2013 Jul 1;73(13):3842-51. doi: 10.1158/0008-5472.CAN-12-1974. Epub 2013 May 23.

Avirulent Toxoplasma gondii generates therapeutic antitumor immunity by reversing immunosuppression in the ovarian cancer microenvironment.

Baird JR1Fox BASanders KLLizotte PHCubillos-Ruiz JRScarlett UKRutkowski MRConejo-Garcia JRFiering SBzik DJ.

Author information

Abstract

Reversing tumor-associated immunosuppression seems necessary to stimulate effective therapeutic immunity against lethal epithelial tumors. Here, we show this goal can be addressed using cps, an avirulent, nonreplicating uracil auxotroph strain of the parasite Toxoplasma gondii (T. gondii), which preferentially invades immunosuppressive CD11c(+) antigen-presenting cells in the ovarian carcinoma microenvironment. Tumor-associated CD11c(+) cells invaded by cps were converted to immunostimulatory phenotypes, which expressed increased levels of the T-cell receptor costimulatory molecules CD80 and CD86. In response to cps treatment of the immunosuppressive ovarian tumor environment, CD11c(+) cellsregained the ability to efficiently cross-present antigen and prime CD8(+) T-cell responses. Correspondingly, cps treatment markedly increased tumor antigen-specific responses by CD8(+) T cells. Adoptive transfer experiments showed that these antitumor T-cell responses were effective in suppressing solid tumor development. Indeed, intraperitoneal cps treatment triggered rejection of established ID8-VegfA tumors, an aggressive xenograft model of ovarian carcinoma, also conferring a survival benefit in a related aggressive model (ID8-Defb29/Vegf-A). The therapeutic benefit of cps treatment relied on expression of IL-12, but it was unexpectedly independent of MyD88 signaling as well as immune experience with T. gondii. Taken together, our results establish that cps preferentially invades tumor-associated antigen-presenting cells and restores their ability to trigger potent antitumor CD8(+) T-cell responses. Immunochemotherapeutic applications of cps might be broadly useful to reawaken natural immunity in the highly immunosuppressive microenvironment of most solid tumors.

 

Oncoimmunology. 2013 Jun 1;2(6):e24677. Epub 2013 Apr 29.

TLR3 agonists improve the immunostimulatory potential of cetuximab against EGFR+ head and neck cancer cells.

Ming Lim C1Stephenson RSalazar AMFerris RL.

Author information

Abstract

Toll-like receptor 3 (TLR3) agonists have been extensively used as adjuvants for anticancer vaccines. However, their immunostimulatory effects and precise mechanisms of action in the presence of antineoplastic monoclonal antibodies (mAbs) have not yet been evaluated. We investigated the effect of TLR3 agonists on cetuximab-mediated antibody-dependent cellular cytotoxicity (ADCC) against head and neck cancer (HNC) cells, as well as on dendritic cell (DC) maturation and cross-priming of epidermal growth factor receptor (EGFR)-specific CD8+ T cells. The cytotoxic activity of peripheral blood mononuclear cells (PBMCs) or isolated natural killer (NK) cells expressing polymorphic variants (at codon 158) of the Fcγ receptor IIIa (FcγIIIa) was determined in 51Cr release assays upon incubation with the TLR3 agonist poly-ICLC. NK cell stimulation was measured based on activation and degranulation markers, while DC maturation in the presence of poly-ICLC was assessed using flow cytometry. The DC-mediated cross priming of EGFR-specific CD8+ T cells was monitored upon in vitro stimulation with tetramer-based flow cytometry. TLR3-stimulated, unfractionated PBMCs from HNC patients mediated robust cetuximab-dependent ADCC, which was abrogated by NK-cell depletion. The cytolytic activity of TLR3-stimulated NK cells differed among cells expressing different polymorphic variants of FcγRIIIa, and NK cells exposed to both poly-ICLC and cetuximab expressed higher levels of CD107a and granzyme B than their counterparts exposed to either stimulus alone. Poly-ICLC plus cetuximab also induced a robust upregulation of CD80, CD83 and CD86 on the surface of DCs, a process that was partially NK-cell dependent. Furthermore, DCs matured in these conditions exhibited improved cross-priming abilities, resulting in higher numbers of EGFR-specific CD8+ T cells. These findings suggest that TLR3 agonists may provide a convenient means to improve the efficacy of mAb-based anticancer regimens.

Ann Oncol. 2012 Sep; 23(Suppl 8): viii6–viii9.

doi:  10.1093/annonc/mds256

PMCID: PMC4085883

Immuno-oncology: understanding the function and dysfunction of the immune system in cancer

  1. J. Finn*

Interactions between the Immune System and Cancer

Evidence has been accumulating since the middle of the last century, first from animal models and later from studies in cancer patients, that the immune system can recognise and reject tumours. The goal of tumour immunology has been to understand the components of the immune system that are important for tumour immunosurveillance and tumour rejection to understand how, when, and why they fail in cases of clinical disease. Immunotherapy, which involves strengthening the cancer patient’s immune system by improving its ability to recognise the tumour or providing a missing immune effector function, is one treatment approach that holds promise of a life-long cure [4].

Studies of cancer–immune system interactions have revealed that every known innate and adaptive immune effector mechanism participates in tumour recognition and control [5]. The first few transformed cells are detected by NK cells through their encounter with specific ligands on tumour cells. This leads to the destruction of some transformed cells and the uptake and processing of their fragments by macrophages and dendritic cells. In turn, these macrophages and dendritic cells are activated to secrete many inflammatory cytokines and present tumour cell-derived molecules to T- and B cells. Activation of T- and B cells leads to the production of additional cytokines that further promote activation of innate immunity and support the expansion and production of tumour-specific T cells and antibodies, respectively. The full power of the adaptive immune system leads to the elimination of remaining tumour cells and, importantly, to the generation of immune memory to specific tumour components that will serve to prevent tumour recurrence.

Effectors of adaptive immunity, such as CD4+ helper T cells, CD8+ cytotoxic T cells, and antibodies, specifically target tumour antigens; i.e. molecules expressed in tumour cells, but not in normal cells. Tumour antigens are normal cellular proteins that are abnormally expressed as a result of genetic mutations, quantitative differences in expression, or differences in posttranslational modifications [5]. In tumour types that have a well-documented viral origin, such as cervical cancer, caused by the human papillomavirus [5], or hepatocellular carcinoma caused by the hepatitis B virus [6], viral proteins can also serve as tumour antigens and targets for antitumour immune response [7].

The first indication that tumours carried molecules distinct from those on the normal cell of origin was derived from immunising mice with human tumours and selecting antibodies that recognised human tumour cells but not their normal counterparts. The major question was whether some, or all, of these molecules would also be recognised by the human immune system. 2011 was an important anniversary for human tumour immunology, marking 20 years since the publication by van der Bruggen et al. [8] that described the cloning of MAGE-1, a gene that encodes a human melanoma antigen recognised by patient’s antitumour T cells. This was not a mutant protein; its recognition by the immune system was due to the fact that it was only expressed by transformed, malignant cells and, with the exception of testicular germ cells, was not expressed in normal adult tissue. Many similar discoveries followed, with each new molecule providing a better understanding of what might be good targets for different forms of cancer immunotherapy. Tumour antigens have been tested as vaccines, as targets for monoclonal antibodies, and as targets for adoptively transferred cytotoxic T cells. There is a wealth of publications from preclinical studies targeting these antigens and results from phase I/II clinical trials. Recently, these studies were critically reviewed and a list of tumour antigens with the largest body of available data compiled [9]. The goal was to encourage faster progress in the design, testing, and approval of immunotherapeutic reagents that incorporate or target the most promising antigens.

 

As highlighted in the article two scenarios which present problems emerged:

  1. In the past, immunotherapy was referred to as ‘passive’ (e.g. the infusion of preformed immune effectors, such as antibodies, cytokines, or activated T cells, NK cells, or lymphokine-activated killer cells), presumably acting directly on the tumour and independent of the immune system or ‘active’ (e.g. vaccines), designed to activate and therefore be dependent on the patient’s immune system. it has since become clear that both passive and active immunotherapies depend on the patient’s immune system for long-term tumour control or complete tumour elimination. anticancer monoclonal antibodies are a well-established class of immunotherapeutic agent. HOWEVER, The potential of these antibodies is drastically undermined by their administration relatively late in the disease course, when the patient’s immune system is largely compromised. Under more optimal conditions, antibody treatment might result not only in the direct cytostatic or cytotoxic effect on the tumour cell, but also in the loading of antibody-bound tumour antigens onto antigen presenting cells (APC) in the tumour microenvironment. The resultant cross-presentation to antitumour T- and B cells could result in additional antibodies to these antigens being produced, and propagation of the immune response at the tumour site would maintain tumour elimination long after the infused monoclonal antibody is gone.
  2. The same scenario could be predicted for adoptively transferred T cells. Unlike antibodies, transferred T cells persist longer and may provide a memory response [14]; however, as long as the memory response is restricted to one clone, or a limited number of clones, then antigen-negative tumours will be able to escape. In addition, cancer vaccines encounter large numbers of immunosuppressive Tregand MDSC in circulation, as well as immunosuppressive cell-derived soluble products that flood the lymph nodes, preventing maturation of APCs and activation of T cells. Even when vaccines are delivered in the context of ex vivo matured and activated dendritic cells, their ability to activate T cells is compromised by the high-level expression of various molecules on T cells that block this process.

The scenarios proposed above present a rather bleak picture of the potential of immunotherapy to achieve the cure for cancer that has eluded standard therapy [15]. Interestingly, failures of some standard therapies are beginning to be ascribed to their inability to activate the patient’s immune system [16]. However, rather than seeing the picture as a deterrent, it should be considered as a road map, providing at least two major directions for new developments in immunotherapy.

The first direction is to continue using the old classes of immunotherapy that target the cancer directly, but to use them in combination with therapies that target the immune system in the tumour microenvironment, such as cytokines, suppressors of Treg or MDSC activity, or antibodies that modulate T-cell activity. The recently approved antibody, ipilimumab, which acts to sustain cytotoxic T-cell activity by augmenting T-cell activation and proliferation, is one example of such an immunomodulatory agent [17].

The other direction is to use immunotherapies, both old and new, for preventing cancer in individuals at high risk [18]. Studies of the tumour microenvironment are providing information about immunosurveillance of tumours from early premalignant lesions to more advanced dysplastic lesions to cancer. At each step, tumour-derived and immune system-derived components have a unique composition that will have distinct effects on immunotherapy. Because these premalignant microenvironments are less developed and immunosuppression is less entrenched, it should be easier to modulate towards the elimination of abnormal cells.

 

Cancer Immunol Immunother. 2011 Sep;60(9):1309-17. doi: 10.1007/s00262-011-1038-y. Epub 2011 May 28.

Tumor immunotherapy using adenovirus vaccines in combination with intratumoral doses of CpG ODN.

Geary SM1Lemke CDLubaroff DMSalem AK.

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Abstract

The combination of viral vaccination with intratumoral (IT) administration of CpG ODNs is yet to be investigated as an immunotherapeutic treatment for solid tumors. Here, we show that such a treatment regime can benefit survival of tumor-challenged mice. C57BL/6 mice bearing ovalbumin (OVA)-expressing EG.7 thymoma tumors were therapeutically vaccinated with adenovirus type 5 encoding OVA (Ad5-OVA), and the tumors subsequently injected with the immunostimulatory TLR9 agonist, CpG-B ODN 1826 (CpG), 4, 7, 10, and 13 days later. This therapeutic combination resulted in enhanced mean survival times that were more than 3.5× longer than naïve mice, and greater than 40% of mice were cured and capable of resisting subsequent tumor challenge. This suggests that an adaptive immune response was generated. Both Ad5-OVA and Ad5-OVA + CpG IT treatments led to significantly increased levels of H-2 K(b)-OVA-specific CD8+ lymphocytes in the peripheral blood and intratumorally. Lymphocyte depletion studies performed in vivo implicated both NK cells and CD8+ lymphocytes as co-contributors to the therapeutic effect. Analysis of tumor infiltrating lymphocytes (TILs) on day 12 post-tumor challenge revealed that mice treated with Ad5-OVA + CpG IT possessed a significantly reduced percentage of regulatory T lymphocytes (Tregs) within the CD4+ lymphocyte population, compared with TILs isolated from mice treated with Ad5-OVA only. In addition, the proportion of CD8+ TILs that were OVA-specific was reproducibly higher in the mice treated with Ad5-OVA + CpG IT compared with other treatment groups. These findings highlight the therapeutic potential of combining intratumoral CpG and vaccination with virus encoding tumor antigen.

 

Adv Drug Deliv Rev. 2009 Mar 28;61(3):268-74. doi: 10.1016/j.addr.2008.12.005. Epub 2009 Jan 7.

CpG oligonucleotide as an adjuvant for the treatment of prostate cancer.

Lubaroff DM1Karan D.

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Abstract

The use of an adenovirus transduced to express a prostate cancer antigen (PSA) as a vaccine for the treatment of prostate cancer has been shown to be active in the destruction of antigen-expressing prostate tumor cells in a pre-clinical model, using Balb/C or PSA transgenic mice. The destruction of PSA-secreting mouse prostate tumors was observed in Ad/PSA immunized mice in a prophylaxis study with 70% of the mice surviving long term tumor free. This successful immunotherapy was not observed in therapeutic studies in which tumors were established before vaccination and the development of anti-PSA immune response was not as easily generated in PSA transgenic mice. Immunization of conventional and transgenic animals was enhanced by incorporating a collagen matrix into the immunizing injection. Therefore the need to strengthen anti-PSA and anti-prostate cancer immunity was an obvious next step in developing a successful prostate cancer immunotherapy. Because the use ofimmunostimulatory CpG motifs was shown to enhance immune responses to a wide variety of antigens, our studies incorporated CpG into the Ad/PSA vaccine experimental plans. The results of the subsequent studies demonstrated a dichotomy where Ad/PSA plus CpG enhanced the in vivo destruction of PSA-secreting tumors and the survival of experimental animals, but revealed that the number and in vitro activities of antigen specific CD8+ T cells was decreased as compared to the values observed when the vaccine alone was used for immunization. The dichotomous observations were confirmed using another antigen system, OVA also incorporated into a replication defective adenovirus. Despite the reduction in antigen-specific CD8+ cells after vaccine plus CpG immunization the enhanced destruction of sc and systemic tumors was shown to be mediated entirely by CD8+ T cells. Finally, the reduction of the CD8+ T cells was the result of an observed decrease in the proliferation of the antigen specific cell population.

J Invest Dermatol. 2004 Aug;123(2):371-9.

 

CpG motifs are efficient adjuvants for DNA cancer vaccines.

Schneeberger A1Wagner CZemann ALührs PKutil RGoos MStingl GWagner SN.

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Abstract

DNA vaccines can induce impressive specific cellular immune response (IR) when taking advantage of their recognition as pathogen-associated molecular patterns (PAMP) through Toll-like receptors (TLR) expressed on/in cells of the innate immune system. Among the many types of PAMP,immunostimulatory DNA, so-called CpG motifs, was shown to interact specifically with TLR9, which is expressed in plasmacytoid dendritic cells(pDC), a key regulatory cell for the activation of innate and adaptive IR. We now report that CpG motifs, when introduced into the backbone, are a useful adjuvant for plasmid-based DNA (pDNA) vaccines to induce melanoma antigen-specific protective T cell responses in the Cloudman M3/DBA/2 model. The CpG-enriched pDNA vaccine induced protection against subsequent challenge with melanoma cells at significantly higher levels than its parental unmodified vector. Preferential induction of an antigen-specific, protective T cell response could be demonstrated by (i) induction of antigen-dependent tumor cell protection, (ii) complete loss of protection by in vivo CD4+/CD8+T cell- but not NK cell-depletion, and (iii) the detection of antigen-specific T cell responses but not of relevant NK cell activity in vitro. These results demonstrate that employing PAMP in pDNA vaccines improves the induction of protective, antigen-specific, T cell-mediated IR.

 

J Biomed Sci. 2016 Jan 25;23(1):16. doi: 10.1186/s12929-016-0238-3.

Combination of the toll like receptor agonist and α-Galactosylceramide as an efficient adjuvant for cancer vaccine.

Gableh F1Saeidi M2Hemati S3Hamdi K4Soleimanjahi H5Gorji A6,7,8Ghaemi A9,10,11.

Author information

Abstract

BACKGROUND:

DNA vaccines have emerged as an attractive approach for the generation of cytotoxic T lymphocytes (CTL). In our previous study, we found That Toll like receptor (TLR) ligands are promising candidates for the development of novel adjuvants for DNA vaccine. To improve the efficacy of DNA vaccine directed against human papillomavirus (HPV) tumors, we evaluated whether co-administration of a TLR4 ligand, monophosphoryl lipid A (MPL), and Natural Killer T Cell Ligand α-Galactosylceramide(α-GalCer) adjuvants with DNA vaccine would influence the anti-tumor efficacy of DNA vaccinations.

METHODS:

We investigated the effectiveness of α-GalCer and MPL combination as an adjuvant with an HPV-16 E7 DNA vaccine to enhance antitumor immune responses.

RESULTS:

By using adjuvant combination for a DNA vaccine, we found that the levels of lymphocyte proliferation, CTL activity, IFN- γ, IL-4 and IL-12 responses, and tumor protection against TC-1 cells were significantly increased compared to the DNA vaccine with individual adjuvants. In addition, inhibition of IL-18 signaling during vaccination decreased IFN-γ responses and tumor protection, and that this inhibition suggested stimulatory role of IL-18 in adjuvant effects of α-GalCer and MPL combination.

CONCLUSION:

The strong adjuvanticity associated with α-GalCer/MPL combination may to be an important tool in the development of novel and strong cancer immunotherapy.

Cancer Sci. 2015 Dec;106(12):1659-68. doi: 10.1111/cas.12824. Epub 2015 Nov 18.

Adjuvant for vaccine immunotherapy of cancer – focusing on Toll-like receptor 2 and 3 agonists for safely enhancing antitumor immunity.

Seya T1Shime H1Takeda Y1Tatematsu M1Takashima K1Matsumoto M1.

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Abstract

Immune-enhancing adjuvants usually targets antigen (Ag)-presenting cells to tune up cellular and humoral immunity. CD141(+) dendritic cells (DC) represent the professional Ag-presenting cells in humans. In response to microbial pattern molecules, these DCs upgrade the maturation stage sufficient to improve cross-presentation of exogenous Ag, and upregulation of MHC and costimulators, allowing CD4/CD8 T cells to proliferate and liberating cytokines/chemokines that support lymphocyte attraction and survival. These DCs also facilitate natural killer-mediated cell damage. Toll-like receptors (TLRs) and their signaling pathways in DCs play a pivotal role in DC maturation. Therefore, providing adjuvants in addition to Ag is indispensable for successful vaccine immunotherapy for cancer, which has been approved in comparison with antimicrobial vaccines. Mouse CD8α(+) DCs express TLR7 and TLR9 in addition to the TLR2 family (TLR1, 2, and 6) and TLR3, whereas human CD141(+) DCs exclusively express the TLR2 family and TLR3. Although human and mouse plasmacytoid DCs commonly express TLR7/9 to respond to their agonists, the results on mouse adjuvant studies using TLR7/9 agonists cannot be simply extrapolated to human adjuvant immunotherapy. In contrast, TLR2 and TLR3 are similarly expressed in both human and mouse Ag-presenting DCs. Bacillus Calmette-Guerin peptidoglycan and polyinosinic-polycytidylic acid are representative agonists for TLR2 and TLR3, respectively, although they additionally stimulate cytoplasmic sensors: their functional specificities may not be limited to the relevant TLRs. These adjuvants have been posted up to a certain achievement in immunotherapy in some cancers. We herein summarize the history and perspectives of TLR2 and TLR3 agonists in vaccine-adjuvant immunotherapy for cancer.

Adv Exp Med Biol. 2015;850:81-91. doi: 10.1007/978-3-319-15774-0_7.

Molecular Programming of Immunological Memory in Natural Killer Cells.

Beaulieu AM1Madera SSun JC.

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Abstract

Immunological memory is a hallmark of the adaptive immune system. Although natural killer (NK) cells have traditionally been classified as a component of the innate immune system, they have recently been shown in mice and humans to exhibit certain features of immunological memory, including an ability to undergo a clonal-like expansion during virus infection, generate long-lived progeny (i.e. memory cells), and mediate recall responses against previously encountered pathogens–all characteristics previously ascribed only to adaptive immune responses by B and T cells in mammals. To date, the molecular events that govern the generation of NK cell memory are not completely understood. Using a mouse model of cytomegalovirus infection, we demonstrate that individual pro-inflammatory IL-12, IL-18, and type I-IFN signaling pathways are indispensible and play non-redundant roles in the generation of virus-specific NK cell memory. Furthermore, we discovered that antigen-specific proliferation and protection by NK cells is mediated by the transcription factor Zbtb32, which is induced by pro-inflammatory cytokines and promotes a cell cycle program in activated NK cells. A greater understanding of the molecular mechanisms controlling NK cell responses will provide novel strategies for tailoring vaccines to target infectious disease.

 

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