Delineating the functional activity of antibodies with cross-reactivity to SARS-CoV-2, SARS-CoV-1 and related sarbecoviruses

• Published in: PLoS pathogens Vol. 20; no. 10; p. e1012650
• Main Authors: Ruiz, Felicitas, Foreman, William B., Lilly, Michelle, Baharani, Viren A., Depierreux, Delphine M., Chohan, Vrasha, Taylor, Ashley L., Guenthoer, Jamie, Ralph, Duncan, Matsen IV, Frederick A., Chu, Helen Y., Bieniasz, Paul D., Côté, Marceline, Starr, Tyler N., Overbaugh, Julie
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 28.10.2024; Public Library of Science (PLoS)
• Subjects: Animals; Antibodies; Antibodies, Neutralizing - immunology; Antibodies, Viral - immunology; Antigen-antibody reactions; Antigenic determinants; B cells; Betacoronavirus - immunology; Biology and life sciences; Care and treatment; Causes of; Coronavirus infections; Coronaviruses; COVID-19 - immunology; COVID-19 - virology; Cross Reactions - immunology; Development and progression; Epitopes - immunology; Health aspects; Humans; Immune response; Immunological research; Medicine and health sciences; Mice; Physiological aspects; Research and Analysis Methods; SARS-CoV-2 - immunology; Severe acute respiratory syndrome-related coronavirus - immunology; Spike Glycoprotein, Coronavirus - immunology; Viral antibodies; United States; China
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1012650

The recurring spillover of pathogenic coronaviruses and demonstrated capacity of sarbecoviruses, such SARS-CoV-2, to rapidly evolve in humans underscores the need to better understand immune responses to this virus family. For this purpose, we characterized the functional breadth and potency of antibodies targeting the receptor binding domain (RBD) of the spike glycoprotein that exhibited cross-reactivity against SARS-CoV-2 variants, SARS-CoV-1 and sarbecoviruses from diverse clades and animal origins with spillover potential. One neutralizing antibody, C68.61, showed remarkable neutralization breadth against both SARS-CoV-2 variants and viruses from different sarbecovirus clades. C68.61, which targets a conserved RBD class 5 epitope, did not select for escape variants of SARS-CoV-2 or SARS-CoV-1 in culture nor have predicted escape variants among circulating SARS-CoV-2 strains, suggesting this epitope is functionally constrained. We identified 11 additional SARS-CoV-2/SARS-CoV-1 cross-reactive antibodies that target the more sequence conserved class 4 and class 5 epitopes within RBD that show activity against a subset of diverse sarbecoviruses with one antibody binding every single sarbecovirus RBD tested. A subset of these antibodies exhibited Fc-mediated effector functions as potent as antibodies that impact infection outcome in animal models. Thus, our study identified antibodies targeting conserved regions across SARS-CoV-2 variants and sarbecoviruses that may serve as therapeutics for pandemic preparedness as well as blueprints for the design of immunogens capable of eliciting cross-neutralizing responses.