General COVID-19 Thread May 19, 2020 7:33:40 GMT
Post by Admin on May 19, 2020 7:33:40 GMT
In a paper published today by the journal Nature, a team including researchers from the University of Washington reports that the antibody, known as S309, can neutralize the virus that causes COVID-19 in lab experiments. “We still need to show that this antibody is protective in living systems, which has not yet been done,” David Veesler, a biochemist at the UW School of Medicine who’s one of the paper’s senior authors, said in a news release.
S309 was one of several promising monoclonal antibodies identified in the memory B cells of a patient who survived Severe Acute Respiratory Syndrome. No cases of SARS have been reported since 2004. Like COVID-19, SARS was caused by a type of coronavirus, which led researchers to check for therapeutic crossover effects.
Combining the S309 antibody with other antibodies identified in the SARS patient’s blood sample enhanced the neutralization effect on the COVID-19 virus, known as SARS-CoV-2. Medications that make use of the antibodies are now on a fast-track development and testing path at California-based Vir Biotechnology in collaboration with GlaxoSmithKline, in preparation for clinical trials.
Veesler and Davide Corti are senior authors of the Nature study, titled “Cross-Neutralization of SARS-CoV-2 by a human monoclonal SARS-CoV Antibody.” Lead authors are Dora Pinto, Young-Jun Park, Martina Beltramello and Alexandra Walls. There are 19 additional co-authors.
Cross-neutralization of SARS-CoV-2 by a human monoclonal SARS-CoV antibody
SARS-CoV-2 is a newly emerged coronavirus responsible for the current COVID-19 pandemic that has resulted in more than 3.7 million infections and 260,000 deaths as of 6 May 20201,2. Vaccine and therapeutic discovery efforts are paramount to curb the pandemic spread of this zoonotic virus. The SARS-CoV-2 spike (S) glycoprotein promotes entry into host cells and is the main target of neutralizing antibodies. Here we describe multiple monoclonal antibodies targeting SARS-CoV-2 S identified from memory B cells of an individual who was infected with SARS-CoV in 2003. One antibody, named S309, potently neutralizes SARS-CoV-2 and SARS-CoV pseudoviruses as well as authentic SARS-CoV-2 by engaging the S receptor-binding domain. Using cryo-electron microscopy and binding assays, we show that S309 recognizes a glycan-containing epitope that is conserved within the sarbecovirus subgenus, without competing with receptor attachment. Antibody cocktails including S309 along with other antibodies identified here further enhanced SARS-CoV-2 neutralization and may limit the emergence of neutralization-escape mutants. These results pave the way for using S309- and S309-containing antibody cocktails for prophylaxis in individuals at high risk of exposure or as a post-exposure therapy to limit or treat severe disease.