Structural changes in the SARS-CoV-2 spike E406W mutant escaping a clinical monoclonal antibody cocktail.

Continued evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is eroding antibody responses elicited by prior vaccination and infection. The SARS-CoV-2 receptor-binding domain (RBD) E406W mutation abrogates neutralization mediated by the REGEN-COV therapeutic monoclonal antibody (mAb) COVID-19 cocktail and the AZD1061 (COV2-2130) mAb. Here, we show that this mutation remodels the receptor-binding site allosterically, thereby altering the epitopes recognized by these three mAbs and vaccine-elicited neutralizing antibodies while remaining functional. Our results demonstrate the spectacular structural and functional plasticity of the SARS-CoV-2 RBD, which is continuously evolving in emerging SARS-CoV-2 variants, including currently circulating strains that are accumulating mutations in the antigenic sites remodeled by the E406W substitution.
Competing Interests: Declaration of interests The Veesler laboratory has received a sponsored research agreement from Vir Biotechnology, Inc. J.D.B. consults for Moderna and Flagship Labs 77 on topics related to viral evolution and is an inventor on Fred Hutch licensed patents related to viral deep mutational scanning. D.C. is an employee of Vir Biotechnology, Inc., and may hold shares in Vir Biotechnology, Inc.
(Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)