针对关注的 SARS-CoV-2 变体的中和抗体的表位分类和 RBD 结合特性。
Epitope Classification and RBD Binding Properties of Neutralizing Antibodies Against SARS-CoV-2 Variants of Concern.
机构信息
Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, United States.
Disease Intervention & Prevention Program, Texas Biomedical Research Institute, San Antonio, TX, United States.
出版信息
Front Immunol. 2021 Jun 4;12:691715. doi: 10.3389/fimmu.2021.691715. eCollection 2021.
Severe acute respiratory syndrome coronavirus-2 (SAR-CoV-2) causes coronavirus disease 2019 (COVID19) that is responsible for short and long-term disease, as well as death, in susceptible hosts. The receptor binding domain (RBD) of the SARS-CoV-2 Spike (S) protein binds to cell surface angiotensin converting enzyme type-II (ACE2) to initiate viral attachment and ultimately viral pathogenesis. The SARS-CoV-2 S RBD is a major target of neutralizing antibodies (NAbs) that block RBD - ACE2 interactions. In this report, NAb-RBD binding epitopes in the protein databank were classified as C1, C1D, C2, C3, or C4, using a RBD binding profile (BP), based on NAb-specific RBD buried surface area and used to predict the binding epitopes of a series of uncharacterized NAbs. Naturally occurring SARS-CoV-2 RBD sequence variation was also quantified to predict NAb binding sensitivities to the RBD-variants. NAb and ACE2 binding studies confirmed the NAb classifications and determined whether the RBD variants enhanced ACE2 binding to promote viral infectivity, and/or disrupted NAb binding to evade the host immune response. Of 9 single RBD mutants evaluated, K417T, E484K, and N501Y disrupted binding of 65% of the NAbs evaluated, consistent with the assignment of the SARS-CoV-2 P.1 Japan/Brazil strain as a variant of concern (VoC). RBD variants E484K and N501Y exhibited ACE2 binding equivalent to a Wuhan-1 reference SARS-CoV-2 RBD. While slightly less disruptive to NAb binding, L452R enhanced ACE2 binding affinity. Thus, the L452R mutant, associated with the SARS-CoV-2 California VoC (B.1.427/B.1.429-California), has evolved to enhance ACE2 binding, while simultaneously disrupting C1 and C2 NAb classes. The analysis also identified a non-overlapping antibody pair (1213H7 and 1215D1) that bound to all SARS-CoV-2 RBD variants evaluated, representing an excellent therapeutic option for treatment of SARS-CoV-2 WT and VoC strains.
严重急性呼吸综合征冠状病毒 2(SARS-CoV-2)引起 2019 年冠状病毒病(COVID19),可导致易感宿主出现短期和长期疾病,甚至死亡。SARS-CoV-2 刺突(S)蛋白的受体结合域(RBD)与细胞表面血管紧张素转换酶 2(ACE2)结合,启动病毒附着并最终导致病毒发病机制。SARS-CoV-2 S RBD 是中和抗体(NAb)的主要靶标,可阻断 RBD-ACE2 相互作用。在本报告中,根据 NAb 特异性 RBD 埋藏表面积,使用 RBD 结合谱(BP)将蛋白质数据库中的 NAb-RBD 结合表位分类为 C1、C1D、C2、C3 或 C4,用于预测一系列未表征的 NAb 的结合表位。还对天然发生的 SARS-CoV-2 RBD 序列变异进行了量化,以预测 NAb 对 RBD 变异的结合敏感性。NAb 和 ACE2 结合研究证实了 NAb 分类,并确定了 RBD 变异是否增强了 ACE2 结合以促进病毒感染性,和/或破坏了 NAb 结合以逃避宿主免疫反应。在评估的 9 个单一 RBD 突变体中,K417T、E484K 和 N501Y 破坏了 65%评估的 NAb 的结合,与将 SARS-CoV-2 P.1 日本/巴西株归类为关注变异株(VOC)一致。RBD 变异体 E484K 和 N501Y 表现出与武汉-1 参考 SARS-CoV-2 RBD 相当的 ACE2 结合。虽然对 NAb 结合的破坏略小,但 L452R 增强了 ACE2 结合亲和力。因此,与 SARS-CoV-2 加利福尼亚 VOC(B.1.427/B.1.429-加利福尼亚)相关的 L452R 突变体已进化为增强 ACE2 结合,同时破坏 C1 和 C2 NAb 类。该分析还鉴定了一对非重叠的抗体(1213H7 和 1215D1),可与评估的所有 SARS-CoV-2 RBD 变异体结合,为治疗 SARS-CoV-2 WT 和 VOC 株提供了极好的治疗选择。