Department of Genetics, Yale University School of Medicine, New Haven, CT, USA.
System Biology Institute, Yale University, West Haven, CT, USA.
Nat Commun. 2022 Mar 28;13(1):1638. doi: 10.1038/s41467-022-29288-3.
COVID-19 pathogen SARS-CoV-2 has infected hundreds of millions and caused over 5 million deaths to date. Although multiple vaccines are available, breakthrough infections occur especially by emerging variants. Effective therapeutic options such as monoclonal antibodies (mAbs) are still critical. Here, we report the development, cryo-EM structures, and functional analyses of mAbs that potently neutralize SARS-CoV-2 variants of concern. By high-throughput single cell sequencing of B cells from spike receptor binding domain (RBD) immunized animals, we identify two highly potent SARS-CoV-2 neutralizing mAb clones that have single-digit nanomolar affinity and low-picomolar avidity, and generate a bispecific antibody. Lead antibodies show strong inhibitory activity against historical SARS-CoV-2 and several emerging variants of concern. We solve several cryo-EM structures at ~3 Å resolution of these neutralizing antibodies in complex with prefusion spike trimer ectodomain, and reveal distinct epitopes, binding patterns, and conformations. The lead clones also show potent efficacy in vivo against authentic SARS-CoV-2 in both prophylactic and therapeutic settings. We also generate and characterize a humanized antibody to facilitate translation and drug development. The humanized clone also has strong potency against both the original virus and the B.1.617.2 Delta variant. These mAbs expand the repertoire of therapeutics against SARS-CoV-2 and emerging variants.
COVID-19 病原体 SARS-CoV-2 已感染数亿人，并导致迄今为止超过 500 万人死亡。尽管有多种疫苗可用，但突破性感染，尤其是新出现的变异株，仍时有发生。有效的治疗方法，如单克隆抗体（mAbs），仍然至关重要。在这里，我们报告了能够有效中和关注的 SARS-CoV-2 变异株的 mAbs 的开发、冷冻电镜结构和功能分析。通过对 Spike 受体结合域（RBD）免疫动物的 B 细胞进行高通量单细胞测序，我们鉴定出两种具有高中和活性的 SARS-CoV-2 中和 mAb 克隆，它们的亲和力为纳摩尔级，亲和力为皮摩尔级，并且产生了一种双特异性抗体。先导抗体对历史 SARS-CoV-2 和几种新出现的关注变异株表现出强烈的抑制活性。我们解决了这些中和抗体与预融合 Spike 三聚体外域复合物的几个冷冻电镜结构，分辨率约为 3Å，并揭示了不同的表位、结合模式和构象。在预防和治疗 SARS-CoV-2 的真实环境中，先导克隆也表现出强大的体内疗效。我们还生成并表征了一种人源化抗体，以促进转化和药物开发。该人源化抗体对原始病毒和 B.1.617.2 Delta 变异株也具有很强的效力。这些 mAbs 扩展了针对 SARS-CoV-2 和新出现的变异株的治疗药物库。
