文献类型： 外文期刊

第一作者： Li, Kun

作者： Li, Kun;Wang, Li;Li, Pinghua;Wang, Sheng;Sun, Pu;Bao, Huifang;Cao, Yimei;Zhu, Guoqiang;Song, Yali;Bai, Xingwen;Ma, Xueqing;Fu, Yuanfang;Yuan, Hong;Zhang, Jing;Wang, Jian;Chen, Yingli;Li, Dong;Liu, Zaixin;Lu, Zengjun;He, Yong;He, Yong;He, Yong;Lou, Zhiyong;He, Yong;Lou, Zhiyong;Liu, Xuerong

作者机构：

关键词： cross-protective antigen sites; foot-and-mouth disease virus; neutralizing antibody; bovine; neutralizing mechanism

期刊名称：JOURNAL OF VIROLOGY （ 影响因子：5.103； 五年影响因子：5.078 ）

ISSN： 0022-538X

年卷期： 2021 年 95 卷 21 期

页码：

收录情况： SCI

摘要： Foot-and-mouth disease virus (FMDV) is a highly contagious virus that infects cloven-hoofed animals. Neutralizing antibodies play critical roles in antiviral infection. Although five known antigen sites that induce neutralizing antibodies have been defined, studies on cross-protective antigen sites are still scarce. We mapped two cross-protective antigen sites using 13 bovine-derived broadly neutralizing monoclonal antibodies (bnAbs) capable of neutralizing 4 lineages within 3 topotypes of FMDV serotype O. One antigen site was formed by a novel cluster of VP3-focused epitopes recognized by bnAb C4 and C4-like antibodies. The cryo-electron microscopy (cryo-EM) structure of the FMDV-OTi (O/Tibet/99)-C4 complex showed close contact with VP3 and a novel interprotomer antigen epitope around the icosahedral 3-fold axis of the FMDV particle, which is far beyond the known antigen site 4. The key determinants of the neutralizing function of C4 and C4-like antibodies on the capsid were beta B (T65), the B-C loop (T68), the E-F loop (E131 and K134), and the H-I loop (G196), revealing a novel antigen site on VP3. The other antigen site comprised two group epitopes on VP2 recognized by 9 bnAbs (B57, B73, B77, B82, F28, F145, F150, E46, and E54), which belong to the known antigen site 2 of FMDV sero-type O. Notably, bnAb C4 potently promoted FMDV RNA release in response to dam-age to viral particles, suggesting that the targeted epitope contains a trigger mechanism for particle disassembly. This study revealed two cross-protective antigen sites that can elicit cross-reactive neutralizing antibodies in cattle and provided new structural information for the design of a broad-spectrum molecular vaccine against FMDV serotype O. IMPORTANCE FMDV is the causative agent of foot-and-mouth disease (FMD), which is one of the most contagious and economically devastating diseases of domestic animals. The antigenic structure of FMDV serotype O is rather complicated, especially for those sites that can elicit a cross-protective neutralizing antibody response. Monoclonal neutralization antibodies provide both crucial defense components against FMDV infection and valuable tools for fine analysis of the antigenic structure. In this study, we found a cluster of novel VP3-focused epitopes using 13 bnAbs against FMDV serotype O from natural host cattle, which revealed two cross-protective antigen sites on VP2 and VP3. Antibody C4 targeting this novel epitope potently promoted viral particle disassembly and RNA release before infection, which may indicate a vulnerable region of FMDV. This study reveals new structural information about cross-protective antigen sites of FMDV serotype O, providing valuable and strong support for future research on broad-spectrum vaccines against FMD.

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