Virus made in lab mimics SARS-CoV-2
The SARS-CoV-2 deadly virus that causes COVID-19 can only be studied safely under high-level biosafety protection. Researches handling the transmittable and infectious virus need to wear full-body biohazard suits with pressurized respirators, as well as work inside laboratories with specialized airflow systems and multiple containment levels. These safety preventative measures slow down efforts to find drugs and vaccines for COVID-19 as the required biosafety facilities are not accessible to lots of researchers.
To aid remedy that, scientists at Washington University School of Medicine in St. Louis have developed a hybrid virus that will certainly make it possible for many more researchers to enter the fight against the COVID-19. By swapping one of its genes for one from SARS-CoV-2, the scientists genetically modified a mild virus. The hybrid virus infects cells and is recognized by antibodies like SARS-CoV-2, however, can be handled in a lab with ordinary safety precautions, which most of the lab has.
The outcome of the research is published in Cell Host & Microbe.
Sean Whelan, PhD, the Marvin A Brennecke Distinguished Professor and Head of the Department of Molecular Microbiology and co-senior author said that he has never ever had this many requests for a scientific material in such a short time period. He added that they have distributed the virus to researchers in Argentina, Brazil, Mexico, Canada, and certainly, throughout the United States. They have requests pending from Germany, and U.K. People came to know that we were working on this and started requesting the product even before we published.
Whelan and his colleagues including Michael S Diamond, MD, PhD, the Herbert S Gasser Professor of Medicine and co-senior author, and Brett Case, PhD, a postdoctoral researcher in Diamond’s laboratory and co-author, and Paul W Rothlauf, a graduate student in Whelan’s laboratory and co-author started working with vesicular stomatitis virus (VSV) to produce a model of SARS-CoV-2 that would be safer to work with. As it is fairly innocuous and easy to manipulate genetically, this virus is a workhorse of virology labs. VSV is primarily a virus of livestock, horses, and pigs, it occasionally infects humans, causing a moderate flu-like disease that lasts 3-5 days.
Proteins are present on the surfaces of viruses which they use to attach and infect cells. The scientists removed VSV’s surface-protein gene and replaced it with the one from SARS-CoV-2, referred to as a spike protein, and dubbed the hybrid virus VSV-SARS-CoV-2. The modification developed a new virus that targets cells like SARS-CoV-2 yet lacks the other genes required to cause extreme disease conditions.
The scientists revealed that the hybrid virus was identified by antibodies significantly like a real SARS-CoV-2 virus that came from a COVID-19 positive patient, by using serum from COVID-19 survivors as well as purified antibodies. Serum or antibodies that protected against the hybrid virus from infecting cells likewise blocked the real SARS-CoV-2 virus from infecting the cells and causing COVID-19. Serum or antibodies that failed to stop the hybrid virus also failed to hinder the coronavirus that causes COVID-19. Additionally, a decoy molecule was similarly efficient at misdirecting both viruses and avoiding them from infecting cells.
Whelan said that people certainly develop antibodies against other proteins of SARS-CoV-2, however, for protection against COVID-19, it’s the antibodies against spike protein that appear to be crucial. Thus, for the human immune system, a virus with a spike protein always looks like SARS-CoV-2.
This VSV-SARS-CoV-2 hybrid virus could help researchers review a series of antibody-based preventives as well as therapies against coronavirus. The hybrid virus could be used to measure whether a COVID-19 survivor has enough neutralizing antibodies to donate plasma to COVID-19 patients, to determine antibodies with the potential to be developed into antiviral medications, or to evaluate whether a speculative vaccine evokes neutralizing antibodies.
Diamond, who is also a professor of molecular microbiology, and of pathology and immunology said that one of the issues in assessing neutralizing antibodies is that a lot of these examinations require a BSL-3 facility, and also the majority of clinical laboratories as well as companies don’t have BSL-3 facility. Using this hybrid virus, you can take the antibodies, plasma or serum, and high-throughput evaluations at BSL-2 facility itself, which every laboratory has, without a threat of getting infected by COVID-19. As well as we know that it associates almost perfectly with the info we get from authentic contagious SARS-CoV-2 coronavirus.
Diamond said that considering that the hybrid virus resembles SARS-CoV-2 to the immune system of the body yet does not develop severe disease conditions, it is a potential vaccine candidate. Diamond, Whelan, and his colleagues are performing studies on animal models to assess the possibility.
Virus made in lab mimics SARS-CoV-2
Author: Sruthi S