Open AccessUncovering a conserved vulnerability site in SARS‐CoV‐2 by a human antibody
Author(s) -
Li Tingting,
Cai Hongmin,
Zhao Yapei,
Li Yanfang,
Lai Yanling,
Yao Hebang,
Liu Liu Daisy,
Sun Zhou,
van Vlissingen Martje Fentener,
Kuiken Thijs,
GeurtsvanKessel Corine H,
Zhang Ning,
Zhou Bingjie,
Lu Lu,
Gong Yuhuan,
Qin Wenming,
Mondal Moumita,
Duan Bowen,
Xu Shiqi,
Richard Audrey S,
Raoul Hervé,
Chen JianFeng,
Xu Chenqi,
Wu Ligang,
Zhou Haisheng,
Huang Zhong,
Zhang Xuechao,
Li Jun,
Wang Yanyan,
Bi Yuhai,
Rockx Barry,
Chen Junfang,
Meng FeiLong,
Lavillette Dimitri,
Li Dianfan
Publication year - 2021
Publication title -
embo molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.923
H-Index - 107
eISSN - 1757-4684
pISSN - 1757-4676
DOI - 10.15252/emmm.202114544
Subject(s) - epitope , neutralization , antibody , virology , biology , monoclonal antibody , mutant , binding site , epitope mapping , receptor , microbiology and biotechnology , genetics , gene
An essential step for SARS‐CoV‐2 infection is the attachment to the host cell receptor by its Spike receptor‐binding domain (RBD). Most of the existing RBD‐targeting neutralizing antibodies block the receptor‐binding motif (RBM), a mutable region with the potential to generate neutralization escape mutants. Here, we isolated and structurally characterized a non‐RBM‐targeting monoclonal antibody (FD20) from convalescent patients. FD20 engages the RBD at an epitope distal to the RBM with a K D of 5.6 nM, neutralizes SARS‐CoV‐2 including the current Variants of Concern such as B.1.1.7, B.1.351, P.1, and B.1.617.2 (Delta), displays modest cross‐reactivity against SARS‐CoV, and reduces viral replication in hamsters. The epitope coincides with a predicted “ideal” vulnerability site with high functional and structural constraints. Mutation of the residues of the conserved epitope variably affects FD20‐binding but confers little or no resistance to neutralization. Finally, in vitro mode‐of‐action characterization and negative‐stain electron microscopy suggest a neutralization mechanism by which FD20 destructs the Spike. Our results reveal a conserved vulnerability site in the SARS‐CoV‐2 Spike for the development of potential antiviral drugs.