Super-potent human antibodies protect against COVID-19 in animal tests
Scientists isolate powerful coronavirus-neutralizing antibodies from
COVID-19 patients and successfully test in animals

Date:
June 15, 2020
Source:
Scripps Research Institute
Summary:
Researchers have discovered antibodies in the blood of recovered
COVID-19 patients that provide powerful protection against
SARS-CoV-2, the coronavirus that causes the disease, when tested
in animals and human cell cultures.



FULL STORY ========================================================================== [Coronavirus illustration | Credit: (c) Mauro Rodrigues / stock.adobe.com] Coronavirus illustration (stock image).

Credit: (c) Mauro Rodrigues / stock.adobe.com [Coronavirus illustration | Credit: (c) Mauro Rodrigues / stock.adobe.com] Coronavirus illustration
(stock image).

Credit: (c) Mauro Rodrigues / stock.adobe.com Close A team led by
Scripps Research has discovered antibodies in the blood of recovered
COVID-19 patients that provide powerful protection against SARS-CoV-
2, the coronavirus that causes the disease, when tested in animals and
human cell cultures.


==========================================================================
The research, published today in Science, offers a paradigm of swift
reaction to an emergent and deadly viral pandemic, and sets the stage
for clinical trials and additional tests of the antibodies, which are
now being produced as potential treatments and preventives for COVID-19.

"The discovery of these very potent antibodies represents an extremely
rapid response to a totally new pathogen," says study co-senior author
Dennis Burton, PhD, the James and Jessie Minor Chair in Immunology in
the Department of Immunology & Microbiology at Scripps Research.

In principle, injections of such antibodies could be given to patients
in the early stage of COVID-19 to reduce the level of virus and protect
against severe disease. The antibodies also may be used to provide
temporary, vaccine-like protection against SARS-CoV-2 infection for
healthcare workers, elderly people and others who respond poorly to
traditional vaccines or are suspected of a recent exposure to the
coronavirus.

The project was led by groups at Scripps Research; IAVI, a nonprofit
scientific research organization dedicated to addressing urgent, unmet
global health challenges; and University of California San Diego School
of Medicine.

"It has been a tremendous collaborative effort, and we're now focused
on making large quantities of these promising antibodies for clinical
trials," says co- lead author Thomas Rogers, MD, PhD, an adjunct
assistant professor in the Department of Immunology & Microbiology at
Scripps Research, and assistant professor of Medicine at UC San Diego.



==========================================================================
An approach that's worked for other deadly viruses Developing a
treatment or vaccine for severe COVID-19 is currently the world's top
public health priority. Globally, almost 8 million people have tested
positive for SARS-CoV-2 infection, and more than 400,000 have died of
severe COVID-19. The daily toll of new infections is still rising.

One approach to new viral threats is to identify, in the blood of
recovering patients, antibodies that neutralize the virus's ability to
infect cells.

These antibodies can then be mass-produced, using biotech methods, as a treatment that blocks severe disease and as a vaccine-like preventive
that circulates in the blood for several weeks to protect against
infection. This approach already has been demonstrated successfully
against Ebola virus and the pneumonia-causing respiratory syncytial virus, commonly known as RSV.

Potent patient antibodies block the virus For the new project, Rogers
and his UC San Diego colleagues took blood samples from patients who
had recovered from mild-to-severe COVID-19. In parallel, scientists
at Scripps Research and IAVI developed test cells that express ACE2,
the receptor that SARS-CoV-2 uses to get into human cells. In a set of
initial experiments, the team tested whether antibody-containing blood
from the patients could bind to the virus and strongly block it from
infecting the test cells.



==========================================================================
The scientists were able to isolate more than 1,000 distinct
antibody-producing immune cells, called B cells, each of which produced a distinct anti-SARS-CoV- 2 antibody. The team obtained the antibody gene sequences from these B cells so that they could produce the antibodies
in the laboratory. By screening these antibodies individually, the team identified several that, even in tiny quantities, could block the virus
in test cells, and one that could also protect hamsters against heavy
viral exposure.

All of this work -- including the development of the cell and animal
infection models, and studies to discover where the antibodies of interest
bind the virus -- was completed in less than seven weeks.

"We leveraged our institution's decades of expertise in antibody isolation
and quickly pivoted our focus to SARS-CoV-2 to identify these highly
potent antibodies," says study co-author Elise Landais, PhD, an IAVI
principal scientist.

If further safety tests in animals and clinical trials in people go well,
then conceivably the antibodies could be used in clinical settings as
early as next January, the researchers say.

"We intend to make them available to those who need them most, including
people in low- and middle-income countries," Landais says.

In the course of their attempts to isolate anti-SARS-CoV-2 antibodies
from the COVID-19 patients, the researchers found one that can also
neutralize SARS-CoV, the related coronavirus that caused the 2002-2004
outbreak of severe acute respiratory syndrome (SARS) in Asia.

"That discovery gives us hope that we will eventually find broadly
neutralizing antibodies that provide at least partial protection against
all or most SARS coronaviruses, which should be useful if another one
jumps to humans," Burton says.

"Rapid isolation of potent SARS-CoV-2 neutralizing antibodies and
protection in a small animal model" was co-authored by 30 scientists
including lead authors Thomas Rogers, Fangzhu Zhao, Deli Huang, and Nathan Beutler, all of Scripps Research. The corresponding authors were Devin
Sok and Joseph Jardine of IAVI, and Dennis Burton of Scripps Research.

Funding was provided by the National Institutes of Health (UM1 AI44462),
the IAVI Neutralizing Antibody Center, the Bill and Melinda Gates
Foundation (OPP 1170236, OPP 1206647, OPP1196345/ INV-008813), the John
and Mary Tu Foundation, and the Pendleton Foundation.


========================================================================== Story Source: Materials provided by Scripps_Research_Institute. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Thomas F. Rogers, Fangzhu Zhao, Deli Huang, Nathan Beutler,
Alison Burns,
Wan-Ting He, Oliver Limbo, Chloe Smith, Ge Song, Jordan Woehl,
Linlin Yang, Robert K. Abbott, Sean Callaghan, Elijah Garcia,
Jonathan Hurtado, Mara Parren, Linghang Peng, Sydney Ramirez,
James Ricketts, Michael J.

Ricciardi, Stephen A. Rawlings, Nicholas C. Wu, Meng Yuan, Davey M.

Smith, David Nemazee, John R. Teijaro, James E. Voss, Ian A. Wilson,
Raiees Andrabi, Bryan Briney, Elise Landais, Devin Sok, Joseph G.

Jardine, Dennis R. Burton. Isolation of potent SARS-CoV-2
neutralizing antibodies and protection from disease in a small
animal model. Science, June 15, 2020; DOI: 10.1126/science.abc7520 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/06/200615140840.htm

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