New study highlights COVID-19’s adaptive strategy for infection

Researchers have discovered a new mechanism by which the SARS-CoV-2 virus, which causes COVID-19, can change its mode of infection in human cells. In a work published in the journal eLife, a team from the University of Minnesota and the Midwest Antiviral Drug Discovery (AViDD) Center found that the virus can alternate between being highly infectious and avoiding detection by the immune system. This understanding is essential to understand the impact of the virus during the pandemic and to predict its potential evolutionary outcomes.

The virus’s spike protein, which is crucial for attaching to and infecting human cells, includes a flexible section known as the receptor binding domain (RBD). Fang Li, Ph.D., and his team at the University of Minnesota made an early breakthrough in the pandemic, discovering that the RBD of SARS-CoV-2 does not always remain in an accessible, “ready” state. connect “. They proposed that the RBD’s ability to change its configuration allows the virus to either unfold itself to bind to human cells or protect itself from immune system antibodies.

In their recent research, the scientists examined the discrepancies between SARS-CoV-2 and its relative, the SARS-CoV-1 virus, responsible for the SARS epidemic of 2002 to 2003. They identified a particular area of ​​the spike protein that determines the configuration of SARS. the RBD. Variations in this segment can move the virus toward a more infectious state by opening, or toward a more elusive state by closing.

“When a new coronavirus first appears in humans, it often encounters minimal immune resistance and tends to be highly infectious,” explained Dr. Li, professor and chair of pharmacology at the faculty of Medicine from the University of Michigan and Midwest Co-Director. AViDD Center. “As immunity develops among individuals, whether through infection or vaccination, the virus may increasingly resort to more elusive strategies to remain undetectable. We have understood how a coronavirus can accomplish this evolution.”

Li added that SARS-CoV-2 was particularly notable for its ability to strike a balance between high transmissibility and the ability to evade the immune system early in the pandemic.

At the Midwest AViDD Center, Dr. Li’s team is also working on innovative treatments using nanobodies – tiny antibodies derived from animals like alpacas – that can target SARS-CoV-2 even when it is in “stealth mode “. The study indicates that these nanobodies have a significant advantage over conventional human antibodies in detecting and neutralizing SARS-CoV-2.

The research was co-led by Dr. Li and Bin Liu, Ph.D., associate professor at the Hormel Institute and Midwest AViDD Center investigator, with significant contributions from postdoctoral pharmacology researchers Qibin Geng and Yushun Wan.