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Archive for the ‘Virtual Drug Molecule Screening targeting SAR-CoV-2 proteins’ Category


Cryo-EM disclosed how the D614G mutation changes SARS-CoV-2 spike protein structure.

Reporter: Dr. Premalata Pati, Ph.D., Postdoc

SARS-CoV-2, the virus that causes COVID-19, has had a major impact on human health globally; infecting a massive quantity of people; causing severe disease and associated long-term health sequelae; resulting in death and excess mortality, especially among older and prone populations; interrupting routine healthcare services; disruptions to travel, trade, education, and many other societal functions; and more broadly having a negative impact on peoples physical and mental health.

It’s need of the hour to answer the questions like what allows the variants of SARS-CoV-2 first detected in the UK, South Africa, and Brazil to spread so quickly? How can current COVID-19 vaccines better protect against them?

Scientists from the Harvard Medical School and the Boston Children’s Hospital help answer these urgent questions. The team reports its findings in the journal “Science a paper entitled “Structural impact on SARS-CoV-2 spike protein by D614G substitution”. The mutation rate of the SARS-CoV-2 virus has rapidly evolved over the past few months, especially at the Spike (S) protein region of the virus, where the maximum number of mutations have been observed by the virologists.

Bing Chen, HMS professor of pediatrics at Boston Children’s, and colleagues analyzed the changes in the structure of the spike proteins with the genetic change by D614G mutation by all three variants. Hence they assessed the structure of the coronavirus spike protein down to the atomic level and revealed the reason for the quick spreading of these variants.


This model shows the structure of the spike protein in its closed configuration, in its original D614 form (left) and its mutant form (G614). In the mutant spike protein, the 630 loop (in red) stabilizes the spike, preventing it from flipping open prematurely and rendering SARS-CoV-2 more infectious.

IMAGE SOURCE: Bing Chen, Ph.D., Boston Children’s Hospital

The work

The mutant spikes were imaged by Cryo-Electron microscopy (cryo-EM), which has resolution down to the atomic level. They found that the D614G mutation (substitution of in a single amino acid “letter” in the genetic code for the spike protein) makes the spike more stable as compared with the original SARS-CoV-2 virus. As a result, more functional spikes are available to bind to our cells’ ACE2 receptors, making the virus more contagious.


Cryo-EM revealed how the D614G mutation changes SARS-CoV-2 spike protein structure.

IMAGE SOURCE:  Zhang J, et al., Science

Say the original virus has 100 spikes,” Chen explained. “Because of the shape instability, you may have just 50 percent of them functional. In the G614 variants, you may have 90 percent that is functional. So even though they don’t bind as well, the chances are greater and you will have an infection

Forthcoming directions by Bing Chen and Team

The findings suggest the current approved COVID-19 vaccines and any vaccines in the works should include the genetic code for this mutation. Chen has quoted:

Since most of the vaccines so far—including the Moderna, Pfizer–BioNTech, Johnson & Johnson, and AstraZeneca vaccines are based on the original spike protein, adding the D614G mutation could make the vaccines better able to elicit protective neutralizing antibodies against the viral variants

Chen proposes that redesigned vaccines incorporate the code for this mutant spike protein. He believes the more stable spike shape should make any vaccine based on the spike more likely to elicit protective antibodies. Chen also has his sights set on therapeutics. He and his colleagues are further applying structural biology to better understand how SARS-CoV-2 binds to the ACE2 receptor. That could point the way to drugs that would block the virus from gaining entry to our cells.

In January, the team showed that a structurally engineered “decoy” ACE2 protein binds to SARS-CoV-2 200 times more strongly than the body’s own ACE2. The decoy potently inhibited the virus in cell culture, suggesting it could be an anti-COVID-19 treatment. Chen is now working to advance this research into animal models.

Main Source:

https://science.sciencemag.org/content/early/2021/03/16/science.abf2303?rss=1

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Miniproteins against the COVID-19 Spike protein may be therapeutic

Reporter: Stephen J. Williams, PhD

https://pharmaceuticalintelligence.com/2020/09/30/miniproteins-against-the-covid-19-spike-protein-may-be-therapeutic/

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T cells recognize recent SARS-CoV-2 variants

Reporter: Aviva Lev-Ari, PhD, RN

CD8+ T cell responses in COVID-19 convalescent individuals target conserved epitopes from multiple prominent SARS-CoV-2 circulating variants 

Andrew D ReddAlessandra NardinHassen KaredEvan M BlochAndrew PekoszOliver LaeyendeckerBrian AbelMichael FehlingsThomas C QuinnAaron A R TobianOpen Forum Infectious Diseases, ofab143, https://doi.org/10.1093/ofid/ofab143Published: 30 March 2021 Article history

Abstract

This study examined whether CD8+ T-cell responses from COVID-19 convalescent individuals (n=30) potentially maintain recognition of the major SARS-CoV-2 variants (n=45 mutations assessed). Only one mutation found in B.1.351-Spike overlapped with a previously identified epitope (1/52), suggesting that virtually all anti-SARS-CoV-2 CD8+ T-cell responses should recognize these newly described variants.

Key words:

CD8+ T cellSARS-CoV-2COVID-19Convalescent patients

Topic: 

SOURCE

https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab143/6189113

Original paper:

Andrew D Redd, Alessandra Nardin, Hassen Kared, Evan M Bloch, Andrew Pekosz, Oliver Laeyendecker, Brian Abel, Michael Fehlings, Thomas C Quinn, Aaron A R Tobian, CD8+ T cell responses in COVID-19 convalescent individuals target conserved epitopes from multiple prominent SARS-CoV-2 circulating variants, Open Forum Infectious Diseases, 2021;, ofab143, https://doi.org/10.1093/ofid/ofab143

Tuesday, March 30, 2021

T cells recognize recent SARS-CoV-2 variants

Healthy Human T CellScanning electron micrograph of a human T lymphocyte (also called a T cell) from the immune system of a healthy donor. NIAID

What

When variants of SARS-CoV-2 (the virus that causes COVID-19) emerged in late 2020, concern arose that they might elude protective immune responses generated by prior infection or vaccination, potentially making re-infection more likely or vaccination less effective. To investigate this possibility, researchers from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and colleagues analyzed blood cell samples from 30 people who had contracted and recovered from COVID-19 prior to the emergence of virus variants. They found that one key player in the immune response to SARS-CoV-2—the CD8+ T cell—remained active against the virus.

The research team was led by NIAID’s Andrew Redd, Ph.D., and included scientists from Johns Hopkins University School of Medicine, Johns Hopkins Bloomberg School of Public Health and the Immunomics-focused company, ImmunoScape.

The investigators asked whether CD8+ T cells in the blood of recovered COVID-19 patients, infected with the initial virus, could still recognize three SARS-CoV-2 variants: B.1.1.7, which was first detected in the United Kingdom; B.1.351, originally found in the Republic of South Africa; and B.1.1.248, first seen in Brazil. Each variant has mutations throughout the virus, and, in particular, in the region of the virus’ spike protein that it uses to attach to and enter cells. Mutations in this spike protein region could make it less recognizable to T cells and neutralizing antibodies, which are made by the immune system’s B cells following infection or vaccination.

Although details about the exact levels and composition of antibody and T-cell responses needed to achieve immunity to SARS-CoV-2 are still unknown, scientists assume that strong and broad responses from both antibodies and T cells are required to mount an effective immune response.  CD8+ T cells limit infection by recognizing parts of the virus protein presented on the surface of infected cells and killing those cells.

In their study of recovered COVID-19 patients, the researchers determined that SARS-CoV-2-specific CD8+ T-cell responses remained largely intact and could recognize virtually all mutations in the variants studied. While larger studies are needed, the researchers note that their findings suggest that the T cell response in convalescent individuals, and most likely in vaccinees, are largely not affected by the mutations found in these three variants, and should offer protection against emerging variants.   

Optimal immunity to SARS-Cov-2 likely requires strong multivalent T-cell responses in addition to neutralizing antibodies and other responses to protect against current SARS-CoV-2 strains and emerging variants, the authors indicate. They stress the importance of monitoring the breadth, magnitude and durability of the anti-SARS-CoV-2 T-cell responses in recovered and vaccinated individuals as part of any assessment to determine if booster vaccinations are needed. 

SOURCE

https://www.nih.gov/news-events/news-releases/t-cells-recognize-recent-sars-cov-2-variants

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The WHO team is expected to soon publish a 300-page final report on its investigation, after scrapping plans for an interim report on the origins of SARS-CoV-2 — the new coronavirus responsible for killing 2.7 million people globally

Reporter: Aviva Lev-Ari, PhD, RN

UPDATED on 4/1/2021

Coronavirus: More work needed to rule out China lab leak theory says WHO

START QUOTE

The head of the World Health Organization (WHO) has said further investigation is needed to conclusively rule out that Covid-19 emerged from a laboratory in China.

Tedros Adhanom Ghebreyesus said that although a lab leak was the least likely cause, more research was needed.

The US and other countries have criticised China for failing to provide the WHO with sufficient data.

Beijing has always dismissed the allegations of a virus leak.

A report by WHO and Chinese experts released on Tuesday, said the lab leak explanation was highly unlikely and the virus had probably jumped from bats to humans via another intermediary animal.

China has yet to respond to the WHO’s latest statement.

‘All hypothesis on the table’

However the theory that the virus might have come from a leak in a laboratory “requires further investigation, potential with additional missions involving specialist experts,” Dr Tedros said on Tuesday.

“Let me say clearly that as far as WHO is concerned, all hypothesis remain on the table,” he added.

The virus was first detected in Wuhan, in China’s Hubei province in late 2019. An international team of experts travelled to to the city in January to probe the origins of the virus.

The team investigated all possibilities, including one theory that the virus had originated at the Wuhan Institute of Virology. The institute is the world’s leading authority on the collection, storage and study of bat coronaviruses.

International criticism

In response to the WHO report, the US and 13 allies including South Korea, Australia and the UK voiced concern over the findings and urged China to provide “full access” to experts.

The statement said the mission to Wuhan was “significantly delayed and lacked access to complete, original data and samples”.

“Scientific missions like these should be able to do their work under conditions that produce independent and objective recommendations and findings.”

The group pledged to work together with the WHO.

Former US President Donald Trump was among those who supported the theory that the virus might have escaped from a lab.

WHO investigation team leader, Peter Ben Embarek said on Tuesday his team had felt under political pressure, including from outside China but said he was never pressed to remove anything from the team’s final report.

He also confirmed his team had found no evidence that any laboratories in Wuhan were involved in the outbreak.

MORE …

SOURCE

https://www.bbc.com/news/world-asia-china-56581246

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Ex-CDC Director Robert Redfield believes COVID-19 came from Wuhan lab

By Lia Eustachewich

March 26, 2021 | 10:03am | Updated

START QUOTE

The former director of the Centers for Disease Control and Prevention believes the virus that causes COVID-19 escaped from a lab in Wuhan, China, according to a new interview.

Robert Redfield told CNN on Friday that it was his “opinion” that SARS-CoV-2 — the new coronavirus responsible for killing 2.7 million people globally — did not evolve naturally.

“I’m of the point of view that I still think the most likely etiology of this pathology in Wuhan was from a laboratory — escaped,” said Redfield, who led the CDC during the height of the pandemic. “Other people don’t believe that. That’s fine. Science will eventually figure it out.”

Researchers believe the deadly and highly transmissible strain of coronavirus behind the global pandemic mutated from a virus that infects animals — namely, bats — to one that sickens humans.

But some believe the virus was somehow released from the Wuhan Institute of Virology — which is the only lab in China authorized to study the most dangerous known pathogens, according to Axios.

“It’s not unusual for respiratory pathogens that are being worked on in a laboratory to infect the laboratory worker. … That’s not implying any intentionality,” Redfield said. “It’s my opinion, right? But I am a virologist. I have spent my life in virology.

“I do not believe this somehow came from a bat to a human and at that moment in time, that the virus came to the human, became one of the most infectious viruses that we know in humanity for human-to-human transmission.”

Redfield said usually when a virus jumps from animals to humans, “it takes a while for it to figure out how to become more and more efficient in human-to-human transmission.”

SOURCE

START QUOTE

What they’re saying: “I’m of the point of view that I still think the most likely etiology of this pathology in Wuhan was from a laboratory. Escaped. Other people don’t believe that. That’s fine. Science will eventually figure it out,” Redfield told CNN’s Sanjay Gupta.

  • “It’s not unusual for respiratory pathogens that are being worked on in a laboratory to infect the laboratory worker. … That’s not implying any intentionality. It’s my opinion, right? But I am a virologist. I have spent my life in virology,” he continued.
  • “I do not believe this somehow came from a bat to a human and at that moment in time that the virus came to the human, became one of the most infectious viruses that we know in humanity for human-to-human transmission.”

Between the lines: Lab accidents in the U.S. are not especially rare, as USA Today’s Alison Young noted in a recent opinion piece arguing why the Wuhan lab theory cannot be ruled out. The CDC itself experienced a possible contamination in a lab where it was making COVID-19 test kits early in the pandemic.

What to watch: The WHO team is expected to soon publish a 300-page final report on its investigation, after scrapping plans for an interim report amid mounting tensions between the U.S. and China.

SOURCE

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A Platform called VirtualFlow: Discovery of Pan-coronavirus Drugs help prepare the US for the Next Coronavirus Pandemic

Reporter: Aviva Lev-Ari, PhD, RN

 

ARTICLE|ONLINE NOW, 102021

A multi-pronged approach targeting SARS-CoV-2 proteins using ultra-large virtual screening

Open AccessPublished:January 04, 2021DOI:https://doi.org/10.1016/j.isci.2020.102021

 

The work was made possible in large part by about $1 million in cloud computing hours awarded by Google through a COVID-19 research grant program.

The work reported, below was sponsored by

  • a Google Cloud COVID-19 research grant. Funding was also provided by the
  • Fondation Aclon,
  • National Institutes of Health (GM136859),
  • Claudia Adams Barr Program for Innovative Basic Cancer Research,
  • Math+ Berlin Mathematics Research Center,
  • Templeton Religion Trust (TRT 0159),
  • U.S. Army Research Office (W911NF1910302), and
  • Chleck Family Foundation

 

Harvard University, AbbVie form research alliance to address emergent viral diseases

This article is part of Harvard Medical School’s continuing coverage of medicine, biomedical research, medical education and policy related to the SARS-CoV-2 pandemic and the disease COVID-19.

Harvard University and AbbVie today announced a $30 million collaborative research alliance, launching a multi-pronged effort at Harvard Medical School to study and develop therapies against emergent viral infections, with a focus on those caused by coronaviruses and by viruses that lead to hemorrhagic fever.

The collaboration aims to rapidly integrate fundamental biology into the preclinical and clinical development of new therapies for viral diseases that address a variety of therapeutic modalities. HMS has led several large-scale, coordinated research efforts launched at the beginning of the COVID-19 pandemic.

“A key element of having a strong R&D organization is collaboration with top academic institutions, like Harvard Medical School, to develop therapies for patients who need them most,” said Michael Severino, vice chairman and president of AbbVie. “There is much to learn about viral diseases and the best way to treat them. By harnessing the power of collaboration, we can develop new therapeutics sooner to ensure the world is better prepared for future potential outbreaks.”

“The cataclysmic nature of the COVID-19 pandemic reminds us how vital it is to be prepared for the next public health crisis and how critical collaboration is on every level—across disciplines, across institutions and across national boundaries,” said George Q. Daley, dean of Harvard Medical School. “Harvard Medical School, as the nucleus of an ecosystem of fundamental discovery and therapeutic translation, is uniquely positioned to propel this transformative research alongside allies like AbbVie.”

AbbVie will provide $30 million over three years and additional in-kind support leveraging AbbVie’s scientists, expertise and facilities to advance collaborative research and early-stage development efforts across five program areas that address a variety of therapeutic modalities:

  • Immunity and immunopathology—Study of the fundamental processes that impact the body’s critical immune responses to viruses and identification of opportunities for therapeutic intervention.

Led by Ulirich Von Andrian, the Edward Mallinckrodt Jr. Professor of Immunopathology in the Blavatnik Institute at HMS and program leader of basic immunology at the Ragon Institute of MGH, MIT and Harvard, and Jochen Salfeld, vice president of immunology and virology discovery at AbbVie.

  • Host targeting for antiviral therapies—Development of approaches that modulate host proteins in an effort to disrupt the life cycle of emergent viral pathogens.

Led by Pamela Silver, the Elliot T. and Onie H. Adams Professor of Biochemistry and Systems Biology in the Blavatnik Institute at HMS, and Steve Elmore, vice president of drug discovery science and technology at AbbVie.

  • Antibody therapeutics—Rapid development of therapeutic antibodies or biologics against emergent pathogens, including SARS-CoV-2, to a preclinical or early clinical stage.

Led by Jonathan Abraham, assistant professor of microbiology in the Blavatnik Institute at HMS, and by Jochen Salfeld, vice president of immunology and virology discovery at AbbVie.

  • Small molecules—Discovery and early-stage development of small-molecule drugs that would act to prevent replication of known coronaviruses and emergent pathogens.

Led by Mark Namchuk, executive director of therapeutics translation at HMS and senior lecturer on biological chemistry and molecular pharmacology in the Blavatnik Institute at HMS, and Steve Elmore, vice president of drug discovery science and technology at AbbVie.

  • Translational development—Preclinical validation, pharmacological testing, and optimization of leading approaches, in collaboration with Harvard-affiliated hospitals, with program leads to be determined.

SOURCE

https://hms.harvard.edu/news/joining-forces

 

 

A Screen Door Opens

Virtual screen finds compounds that could combat SARS-CoV-2

This article is part of Harvard Medical School’s continuing coverage of medicine, biomedical research, medical education, and policy related to the SARS-CoV-2 pandemic and the disease COVID-19.

Less than a year ago, Harvard Medical School researchers and international colleagues unveiled a platform called VirtualFlow that could swiftly sift through more than 1 billion chemical compounds and identify those with the greatest promise to become disease-specific treatments, providing researchers with invaluable guidance before they embark on expensive and time-consuming lab experiments and clinical trials.

Propelled by the urgent needs of the pandemic, the team has now pushed VirtualFlow even further, conducting 45 screens of more than 1 billion compounds each and ranking the compounds with the greatest potential for fighting COVID-19—including some that are already approved by the FDA for other diseases.

“This was the largest virtual screening effort ever done,” said VirtualFlow co-developer Christoph Gorgulla, research fellow in biological chemistry and molecular pharmacology in the labs of Haribabu Arthanari and Gerhard Wagner in the Blavatnik Institute at HMS.

The results were published in January in the open-access journal iScience.

The team searched for compounds that bind to any of 15 proteins on SARS-CoV-2 or two human proteins, ACE2 and TMPRSS2, known to interact with the virus and enable infection.

Researchers can now explore on an interactive website the 1,000 most promising compounds from each screen and start testing in the lab any ones they choose.

The urgency of the pandemic and the sheer number of candidate compounds inspired the team to release the early results to the scientific community.

“No one group can validate all the compounds as quickly as the pandemic demands,” said Gorgulla, who is also an associate of the Department of Physics at Harvard University. “We hope that our colleagues can collectively use our results to identify potent inhibitors of SARS-CoV-2.

In most cases, it will take years to find out whether a compound is safe and effective in humans. For some of the compounds, however, researchers have a head start.

Hundreds of the most promising compounds that VirtualFlow flagged are already FDA approved or being studied in clinical or preclinical trials for other diseases. If researchers find that one of those compounds proves effective against SARS-CoV-2 in lab experiments, the data their colleagues have already collected could save time establishing safety in humans.

Other compounds among VirtualFlow’s top hits are currently being assessed in clinical trials for COVID-19, including several drugs in the steroid family. In those cases, researchers could build on the software findings to investigate how those drug candidates work at the molecular level—something that’s not always clear even when a drug works well.

It shows what we’re capable of computationally during a pandemic.

Hari Arthanari

SOURCE

https://hms.harvard.edu/news/screen-door-opens?utm_source=Silverpop&utm_medium=email&utm_term=field_news_item_1&utm_content=HMNews02012021

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