Department of Immunology and Microbiology, Scripps Research Institute, La Jolla, CA 92037, USA.
IAVI Neutralizing Antibody Center, Scripps Research Institute, La Jolla, CA 92037, USA.
Sci Signal. 2023 Aug 15;16(798):eabk3516. doi: 10.1126/scisignal.abk3516.
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) underscores the need for strategies to rapidly develop neutralizing monoclonal antibodies that can function as prophylactic and therapeutic agents and to help guide vaccine design. Here, we demonstrate that engineering approaches can be used to refocus an existing antibody that neutralizes one virus but not a related virus. Through a rapid affinity maturation strategy, we engineered CR3022, a SARS-CoV-1-neutralizing antibody, to bind to the receptor binding domain of SARS-CoV-2 with >1000-fold increased affinity. The engineered CR3022 neutralized SARS-CoV-2 and provided prophylactic protection from viral challenge in a small animal model of SARS-CoV-2 infection. Deep sequencing throughout the engineering process paired with crystallographic analysis of engineered CR3022 elucidated the molecular mechanisms by which the antibody can accommodate sequence differences in the epitopes between SARS-CoV-1 and SARS-CoV-2. This workflow provides a blueprint for the rapid broadening of neutralization of an antibody from one virus to closely related but resistant viruses.
严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 的出现凸显了需要制定策略，快速开发能够作为预防和治疗药物的中和单克隆抗体，并帮助指导疫苗设计。在这里，我们证明工程方法可用于重新聚焦一种现有的抗体，该抗体能中和一种病毒但不能中和相关病毒。通过快速亲和力成熟策略，我们对中和 SARS-CoV-1 的抗体 CR3022 进行了工程改造，使其与 SARS-CoV-2 的受体结合域结合的亲和力增加了 1000 多倍。该工程化的 CR3022 中和了 SARS-CoV-2，并在 SARS-CoV-2 感染的小动物模型中提供了预防病毒攻击的保护。在整个工程过程中进行的深度测序，并结合对工程化的 CR3022 的晶体学分析，阐明了该抗体如何适应 SARS-CoV-1 和 SARS-CoV-2 之间表位的序列差异的分子机制。该工作流程为快速扩大一种抗体对一种病毒的中和作用提供了蓝图，使其能够对密切相关但具有抗性的病毒进行中和。
