A natural mutation between SARS-CoV-2 and SARS-CoV determines neutralization by a cross-reactive antibody.
A natural mutation between SARS-CoV-2 and SARS-CoV determines neutralization by a cross-reactive antibody.
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SARS-COV-2和SARS-COV之间的自然突变决定了交叉反应抗体中和。
DOI：
10.1371/journal.ppat.1009089
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发表时间：
2020-12
期刊：
影响因子：
6.7
通讯作者：
Wilson IA
中科院分区：
文献类型：
--
作者：
Wu NC;Yuan M;Bangaru S;Huang D;Zhu X;Lee CD;Turner HL;Peng L;Yang L;Burton DR;Nemazee D;Ward AB;Wilson IA
在SARS样冠状病毒中保守的表位是设计交叉反应性疫苗和治疗剂的有吸引力的靶标。CR 3022是SARS-CoV中和抗体，针对刺突蛋白上受体结合结构域（RBD）上的高度保守表位，其能够与SARS-CoV-2交叉反应，但亲和力较低。使用X射线晶体学，诱变和结合实验，我们说明了四个氨基酸的差异CR 3022表位之间的SARS-CoV-2和SARS-CoV，一个单一的突变P384 A完全决定了亲和力的差异。CR 3022不能中和SARS-CoV-2，但对SARS-CoV-2 P384 A突变体的亲和力增加，现在能够以与SARS-CoV相似的效力中和。我们进一步研究了CR 3022与SARS-CoV刺突蛋白的相互作用，通过负染EM和冷冻EM。每个三聚体有三个CR 3022 Fab与RBD结合，由于RBD的相当大的灵活性，在不同的向上构象中观察到RBD。在这些构象之一中，四级相互作用由CR 3022与相邻亚基的N-末端结构域（NTD）进行。总的来说，这项研究提供了对SARS样病毒抗原变异和潜在交叉中和表位的见解。持续的COVID-19大流行是由SARS-CoV-2引起的。由于SARS-CoV-2和SARS-CoV的遗传相似性，在2003年引起了流行，现在已经发现一些SARS-CoV抗体也与SARS-CoV-2交叉反应。一种这样的抗体是CR 3022，它是14年前从一名恢复期SARS患者中分离出来的。然而，与SARS-CoV-2相比，与SARS-CoV-2的100倍低的结合不能中和SARS-CoV-2。这项研究表明，SARS-CoV和SARS-COV-2之间CR 3022表位的四个突变差异之一（P384 A）完全解释了CR 3022结合亲和力和中和性的差异。这些发现推进了我们对SARS样冠状病毒之间抗体交叉反应性的理解，并对疫苗和治疗设计产生了影响。
Epitopes that are conserved among SARS-like coronaviruses are attractive targets for design of cross-reactive vaccines and therapeutics. CR3022 is a SARS-CoV neutralizing antibody to a highly conserved epitope on the receptor binding domain (RBD) on the spike protein that is able to cross-react with SARS-CoV-2, but with lower affinity. Using x-ray crystallography, mutagenesis, and binding experiments, we illustrate that of four amino acid differences in the CR3022 epitope between SARS-CoV-2 and SARS-CoV, a single mutation P384A fully determines the affinity difference. CR3022 does not neutralize SARS-CoV-2, but the increased affinity to SARS-CoV-2 P384A mutant now enables neutralization with a similar potency to SARS-CoV. We further investigated CR3022 interaction with the SARS-CoV spike protein by negative-stain EM and cryo-EM. Three CR3022 Fabs bind per trimer with the RBD observed in different up-conformations due to considerable flexibility of the RBD. In one of these conformations, quaternary interactions are made by CR3022 to the N-terminal domain (NTD) of an adjacent subunit. Overall, this study provides insights into antigenic variation and potential cross-neutralizing epitopes on SARS-like viruses. The ongoing COVID-19 pandemic is caused by SARS-CoV-2. Due to the genetic similarity of SARS-CoV-2 and SARS-CoV, which caused an epidemic in 2003, a few of the SARS-CoV antibodies have now been found to also cross-react with SARS-CoV-2. One such antibody is CR3022, which was isolated from a convalescent SARS patient 14 years ago. However, the 100-fold lower binding to SARS-CoV-2 does not enable neutralization of SARS-CoV-2 compared to SARS-CoV. This study shows that one (P384A) of the four mutational differences in the CR3022 epitope between SARS-CoV and SARS-COV-2 fully accounts for the differences in CR3022 binding affinity and neutralization. These findings advance our understanding of antibody cross-reactivity among SARS-like CoVs with implications for vaccine and therapeutic design.