An ultrapotent RBD-targeted biparatopic nanobody neutralizes broad SARS-CoV-2 variants

作者：Xiaojing Chi, Xinhui Zhang, Shengnan Pan, Yanying Yu, Yujin Shi, Tianli Lin, Huarui Duan, Xiuying Liu, Wenfang Chen, Xuehua Yang, Lan Chen, Xiaoqian Dong, Lili Ren, Qiang Ding, Jianwei Wang, Wei Yang · 发表于：Signal Transduction and Targeted Therapy · 年份：2022 · DOI：10.1038/s41392-022-00912-4 · 被引用次数：64 · 研究领域：SARS-CoV-2 and COVID-19 Research、Monoclonal and Polyclonal Antibodies Research、vaccines and immunoinformatics approaches

Abstract 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 at sub-nanomolar levels, 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 RB...