Researchers develop new tools to quickly test anti-coronavirus antibody activity

Researchers at the Rockefeller University in New York have developed a new tool to rapidly test the ability of antibodies to neutralize SARS-CoV-2, a novel coronavirus responsible for the COVID-19 pandemic. The approach described today Experimental Medicine Journal (JEM) To help researchers understand whether patients are susceptible to reinfection with SARS-CoV-2, evaluate the efficacy of vaccines, and develop antibody-based therapies for the disease. Useful

People infected with SARS-CoV-2 produce neutralization antibody By binding to spike proteins on the surface of the virus, it prevents the virus from infecting cells. Earlier studies have suggested that the strength of this antibody response varies greatly from patient to patient, and it is unclear how long such neutralizing antibodies persist in the blood to provide protection against reinfection. It remains.

In the meantime, efforts are underway to treat and prevent COVID-19 using either purified antibodies or whole blood plasma collected from convalescent patients who produce large amounts of neutralizing antibodies. Moreover, a successful vaccine against SARS-CoV-2 should induce the production of neutralizing antibodies.

“Neutralizing Antibodies Reduce the Global Burden of COVID-19 Disease, Caused by Natural Infections and Vaccinations, Administered as Convalescent Plasma, or Recombinant “It will be extremely important for us,” said Paul D. Vienius, professor at Rockefeller University, a researcher at the Howard Hughes Medical Institute. “Therefore, the availability of a rapid, convenient, and accurate assay to measure neutralizing antibody activity assesses naturally acquired or artificially induced immunity to SARS-CoV-2. Is important for.”

Antibody testing using the SARS-CoV-2 virus itself is labor-intensive, must be performed at a Biosafety Level 3 facility, and its widespread application is limited. Therefore, Bieniasz and colleagues have developed several safer surrogate viruses that can be used in place of SARS-CoV-2 to test the neutralizing activity of antibodies that target coronavirus spike proteins.

The surrogate virus is human immunodeficiency virus type 1 (HIV-1) or Vesicular stomatitis virus (VSV) Produces a SARS-CoV-2 spike protein rather than a proprietary surface protein. Some of these surrogate viruses are not able to replicate, making them safer to use in the laboratory. In addition, because the virus is designed to generate fluorescent or luminescent infected cells, researchers can track the infection and easily measure how well this process is blocked by potentially neutralizing antibodies. ..

Bieniasz and colleagues tested the ability of convalescent patient plasma samples and purified antibodies to block the entry of surrogate viruses into human cells grown in the laboratory. “Each of the deputies VirusA quantitative measure of neutralizing activity has been generated that correlates well with the neutralization measured using real SARS-CoV-2,” says Rockefeller’s research associate professor, who conducted the collaboration with Bieniasz. Theodora Hatziioannou says. We have already used these assays to determine the neutralizing potency of hundreds of plasma samples and monoclonal antibodies in a Biosafety Level 2 laboratory. “

Bieniasz adds: “Automation and additional miniaturization are certainly feasible to further increase throughput. Considering the huge number of vaccine candidates in the development pipeline, this is a notable consideration. These surrogate viruses and assays are I think it will be very helpful in reducing COVID-19. Pandemic.”