RT Journal Article
SR Electronic
T1 An ultrapotent RBD-targeted biparatopic nanobody neutralizes broad SARS-CoV-2 variants
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.12.25.474052
DO 10.1101/2021.12.25.474052
A1 Xiaojing Chi
A1 Xinhui Zhang
A1 Shengnan Pan
A1 Yanying Yu
A1 Tianli Lin
A1 Huarui Duan
A1 Xiuying Liu
A1 Wenfang Chen
A1 Xuehua Yang
A1 Qiang Ding
A1 Jianwei Wang
A1 Wei Yang
YR 2021
UL http://biorxiv.org/content/early/2021/12/25/2021.12.25.474052.abstract
AB The wide transmission and host adaptation of SARS-CoV-2 have led to the rapid accumulation of mutations, posing significant challenges to the effectiveness of vaccines and therapeutic antibodies. Although several neutralizing antibodies were authorized for emergency clinical use, convalescent patients derived natural antibodies are vulnerable to SARS-CoV-2 Spike mutation. Here, we describe the screen of a panel of SARS-CoV-2 receptor-binding domain (RBD) targeted nanobodies (Nbs) from a synthetic library and the design of a biparatopic Nb, named Nb1-Nb2, with tight affinity and super wide neutralization breadth against multiple SARS-CoV-2 variants of concern. Deep-mutational scanning experiments identify the potential binding epitopes of the Nbs on the RBD and demonstrate that biparatopic Nb1-Nb2 has a strong escape resistant feature against more than 60 tested RBD amino acid substitutions. Using pseudovirion-based and trans-complementation SARS-CoV-2 tools, we determine that the Nb1-Nb2 broadly neutralizes multiple SARS-CoV-2 variants, including Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), Lambda (C.37), Kappa (B.1.617.1) and Mu (B.1.621). Furthermore, a heavy chain antibody is constructed by fusing the human IgG1 Fc to Nb1-Nb2 (designated as Nb1-Nb2-Fc) to improve its neutralization potency, yield, stability and potential half-life extension. For the new Omicron variant (B.1.1.529) that harbors unprecedented multiple RBD mutations, Nb1-Nb2-Fc keeps a firm affinity (KD < 1.0×10−12 M) and strong neutralizing activity (IC50 = 0.0017 nM). Together, we developed a tetravalent biparatopic human heavy chain antibody with ultrapotent and broad-spectrum SARS-CoV-2 neutralization activity which highlights the potential clinical applications.Competing Interest StatementA patent application has been filed on the nanobodies reported in this study.