Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA.
Vitalant Research Institute and Department of Laboratory Medicine, University of California San Francisco, University of California San Francisco, California, USA.
MAbs. 2021 Jan-Dec;13(1):1893426. doi: 10.1080/19420862.2021.1893426.
Numerous neutralizing antibodies that target SARS-CoV-2 have been reported, and most directly block binding of the viral Spike receptor-binding domain (RBD) to angiotensin-converting enzyme II (ACE2). Here, we deliberately exploit non-neutralizing RBD antibodies, showing they can dramatically assist in neutralization when linked to neutralizing binders. We identified antigen-binding fragments (Fabs) by phage display that bind RBD, but do not block ACE2 or neutralize virus as IgGs. When these non-neutralizing Fabs were assembled into bispecific VH/Fab IgGs with a neutralizing VH domain, we observed a ~ 25-fold potency improvement in neutralizing SARS-CoV-2 compared to the mono-specific bi-valent VH-Fc alone or the cocktail of the VH-Fc and IgG. This effect was epitope-dependent, reflecting the unique geometry of the bispecific antibody toward Spike. Our results show that a bispecific antibody that combines both neutralizing and non-neutralizing epitopes on Spike-RBD is a promising and rapid engineering strategy to improve the potency of SARS-CoV-2 antibodies.
已经报道了许多针对 SARS-CoV-2 的中和抗体，其中大多数抗体可直接阻断病毒刺突受体结合域（RBD）与血管紧张素转化酶 II（ACE2）的结合。在这里，我们故意利用非中和性 RBD 抗体，表明当与中和结合物连接时，它们可以显著增强中和作用。我们通过噬菌体展示鉴定了与 RBD 结合但不阻断 ACE2 或中和病毒的抗原结合片段（Fabs）作为 IgG。当这些非中和性 Fab 组装成双特异性 VH/Fab IgG 并与中和性 VH 结构域结合时，与单特异性双价 VH-Fc 相比，我们观察到针对 SARS-CoV-2 的中和效力提高了约 25 倍中和或 IgG 鸡尾酒。这种效应是表位依赖性的，反映了针对 Spike 的双特异性抗体的独特几何形状。我们的研究结果表明，结合 Spike-RBD 上中和和非中和表位的双特异性抗体是一种很有前途和快速的工程策略，可以提高 SARS-CoV-2 抗体的效力。
Zotero 插件
