@article{96a34452ef3d40439bf486e1da18c005,
title = "Structural mechanism of SARS-CoV-2 neutralization by two murine antibodies targeting the RBD",
abstract = "The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has necessitated the rapid development of antibody-based therapies and vaccines as countermeasures. Here, we use cryoelectron microscopy (cryo-EM) to characterize two protective anti-SARS-CoV-2 murine monoclonal antibodies (mAbs) in complex with the spike protein, revealing similarities between epitopes targeted by human and murine B cells. The more neutralizing mAb, 2B04, binds the receptor-binding motif (RBM) of the receptor-binding domain (RBD) and competes with angiotensin-converting enzyme 2 (ACE2). By contrast, 2H04 binds adjacent to the RBM and does not compete for ACE2 binding. Naturally occurring sequence variants of SARS-CoV-2 and corresponding neutralization escape variants selected in vitro map to our structurally defined epitopes, suggesting that SARS-CoV-2 might evade therapeutic antibodies with a limited set of mutations, underscoring the importance of combination mAb therapeutics. Finally, we show that 2B04 neutralizes SARS-CoV-2 infection by preventing ACE2 engagement, whereas 2H04 reduces host cell attachment without directly disrupting ACE2-RBM interactions, providing distinct inhibitory mechanisms used by RBD-specific mAbs.",
keywords = "ACE2, COVID-19, RBD, SARS-CoV-2, antibody neutralization, biolayer interferometry, cryo-EM, spike, variants of concern",
author = "Errico, {John M.} and Haiyan Zhao and Chen, {Rita E.} and Zhuoming Liu and Case, {James Brett} and Meisheng Ma and Schmitz, {Aaron J.} and Rau, {Michael J.} and Fitzpatrick, {James A.J.} and Shi, {Pei Yong} and Diamond, {Michael S.} and Whelan, {Sean P.J.} and Ellebedy, {Ali H.} and Fremont, {Daved H.}",
note = "Funding Information: This work was supported by National Institute of Allergy and Infectious Diseases contract 75N93019C00062 (to M.S.D., A.H.E., and D.H.F.), contract HHSN272201700060C (to D.H.F.), and grant R01 AI157155 (to M.S.D.). We gratefully acknowledge Raul Andino, Charles Chiu, Mehul Suthar, and BEI for contributing SARS-CoV-2 variant strains, and members of the Fremont and Diamond laboratories for valuable discussions. Funding Information: This work was supported by National Institute of Allergy and Infectious Diseases contract 75N93019C00062 (to M.S.D. A.H.E. and D.H.F.), contract HHSN272201700060C (to D.H.F.), and grant R01 AI157155 (to M.S.D.). We gratefully acknowledge Raul Andino, Charles Chiu, Mehul Suthar, and BEI for contributing SARS-CoV-2 variant strains, and members of the Fremont and Diamond laboratories for valuable discussions. J.M.E. H.Z. Z.L. S.P.J.W. and D.H.F. designed the experiments and D.H.F. supervised the project. J.M.E. M.J.R. and J.A.J.F. collected cryo-EM data. J.M.E. processed cryo-EM data, built models, and performed structural analyses. H.Z. and M.M. expressed recombinant proteins. H.Z. performed the BLI experiments and pre- and post-attachment experiments. H.Z. and J.B.C. performed SARS-CoV-2 cellular binding inhibition studies. R.E.C. tested neutralization against variants; P.-Y.S. provided variant SARS-CoV-2 viruses; A.J.S. and A.H.E. generated and provided the recombinant mAbs; and J.M.E. generated Fabs. J.M.E. H.Z. Z.L. S.P.J.W. M.S.D. and D.H.F. analyzed the data. J.M.E. H.Z. and D.H.F. wrote the initial manuscript, with all authors providing editorial input. D.H.F. is a founder of Courier Therapeutics. A.H.E. is a consultant for Inbios and Fimbrion Therapeutics. M.S.D. is a consultant for Inbios, Vir Biotechnology, and NGM Biopharmaceuticals and is on the Scientific Advisory Board of Moderna and Immunome. D.H.F. M.S.D. and A.H.E. have received unrelated funding support from Emergent BioSolutions. M.S.D. has sponsored research agreements from Moderna and Vir Biotechnology, A.H.E. has a sponsored research agreement from Abbvie, and D.H.F. has a sponsored research agreement from Mallinckrodt Pharmaceuticals. Publisher Copyright: {\textcopyright} 2021 The Author(s)",
year = "2021",
month = oct,
day = "26",
doi = "10.1016/j.celrep.2021.109881",
language = "English",
volume = "37",
journal = "Cell Reports",
issn = "2211-1247",
number = "4",
}