SARS-CoV-2 Omicron sub-variants have generated a world-wide health crisis due to resistance to most approved SARS-CoV-2 neutralizing antibodies and evasion of vaccination-induced antibodies. To manage Omicron sub-variants and prepare for potential new variants, additional means of isolating broad and potent humanized SARS-CoV-2-neutralizing antibodies are desirable. Here, we describe a mouse model in which the primary B cell receptor (BCR) repertoire is generated solely through V(D)J recombination of a human V H 1-2 heavy chain (HC) and, substantially, a human Vκ1-33 light chain (LC). Thus, primary humanized BCR repertoire diversity in these mice derives from immensely diverse HC and LC antigen-contact complementarity-region-3 (CDR3) sequences generated by non-templated junctional modifications during V(D)J recombination. Immunizing the human V H 1-2/Vκ1-33-rearranging mouse model with SARS-CoV-2 (Wuhan-Hu-1) spike protein immunogens elicited several V H 1-2/Vκ1-33-based neutralizing antibodies that bound RBD in a different mode from each other and from those of many prior human patient-derived V H 1-2-based neutralizing antibodies. Of these, SP1-77 potently and broadly neutralized all SARS-CoV-2 variants through BA.5. Cryo-EM studies revealed that SP1-77 bound RBD away from the receptor-binding-motif via a CDR3-dominated recognition mode. Lattice-light-sheet-microscopy-based studies showed that SP1-77 did not block ACE2-mediated viral attachment or endocytosis, but rather blocked viral-host membrane fusion. The broad and potent SP1-77 neutralization activity and non-traditonal mechanism of action suggest this antibody might have therapeutic potential. Likewise, the SP1-77 binding epitope may further inform on vacccine strategies. Finally, the general class of humanized mouse models we have described may contribute to identifying therapeutic antibodies against future SARS-CoV-2 variants and other pathogens.

中文翻译：

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来自单个人 VH 重排小鼠的抗体通过抑制膜融合通过 BA.5 中和所有 SARS-CoV-2 变体


由于对大多数批准的 SARS-CoV-2 中和抗体具有抵抗力并逃避疫苗接种诱导的抗体，SARS-CoV-2 Omicron 亚变体已造成世界范围的健康危机。为了管理 Omicron 亚变体并为潜在的新变体做好准备，需要使用其他方法来分离广泛且有效的人源化 SARS-CoV-2 中和抗体。在这里，我们描述了一种小鼠模型，其中初级 B 细胞受体 (BCR) 库仅通过人类 V 的 V(D)J 重组而产生H 1-2 重链 (HC) 和基本上人 Vκ1-33 轻链 (LC)。因此，这些小鼠中的主要人源化 BCR 库多样性源自 V(D)J 重组过程中非模板化连接修饰产生的极其多样化的 HC 和 LC 抗原接触互补区 3 (CDR3) 序列。免疫人类V H 1-2/Vκ1-33-用 SARS-CoV-2 (Wuhan-Hu-1) 刺突蛋白免疫原重排小鼠模型引发了数个 V H基于 1-2/Vκ1-33 的中和抗体，它们以彼此不同的方式结合 RBD，并且与许多先前人类患者衍生的 V 的结合方式不同H 1-2 型中和抗体。其中，SP1-77 通过 BA.5 有效且广泛地中和了所有 SARS-CoV-2 变体。冷冻电镜研究表明，SP1-77 通过 CDR3 主导的识别模式将 RBD 与受体结合基序结合。基于晶格光片显微镜的研究表明，SP1-77 不会阻断 ACE2 介导的病毒附着或内吞作用，而是阻断病毒与宿主膜的融合。广泛而有效的 SP1-77 中和活性和非传统的作用机制表明该抗体可能具有治疗潜力。 同样，SP1-77 结合表位可能进一步为疫苗策略提供信息。最后，我们描述的一般类人源化小鼠模型可能有助于识别针对未来 SARS-CoV-2 变体和其他病原体的治疗性抗体。