08 Jul,2020

Pamela Bjorkman’s research article on Cell about SARS-CoV-2 virus study

Source: WLA

On June 23, Prof. Bjorkman and her colleagues published one new research article on Cell about SARS-CoV-2 virus study. The article was posted online with the title “Structures of human antibodies bound to SARS-CoV-2 spike reveal common epitopes and recurrent features of antibodies”. Neutralizing antibody responses to coronaviruses mainly target the receptor-binding domain (RBD) of the trimeric spike. Here, the team characterized polyclonal IgGs and Fabs from COVID-19 convalescent individuals for recognition of coronavirus spikes. Plasma IgGs differed in their focus on RBD epitopes, Recognition of alpha- and beta coronaviruses, and contributions of avidity to increased binding/neutralization of IgGs over Fabs. Using electron microscopy, the authors examined specificities of polyclonal plasma Fabs, revealing recognition of both S1A and RBD epitopes on SARS-CoV-2 spike. Moreover, a 3.4Å cryo-EM structure of a neutralizing monoclonal Fab-spike complex revealed an epitope that blocks ACE2 receptor binding. Modeling based on these structures suggested different potentials for inter-spike crosslinking by IgGs on viruses and that characterized IgGs would not be affected by identified SARS-CoV-2 spike mutations. Overall, these studies structurally define a recurrent anti-SARS-CoV- 2 antibody class derived from VH3-53/VH3-66 and similarity to a SARS-CoV VH3 30 antibody, providing criteria for evaluating vaccine-elicited antibodies.