Zou Wanying, Li Qingmei, Li Chunzhen, Meng Zekun, Sun Yaning, Yang Suzhen, Guo Junqing, Zhang Gaiping
International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China; Institute for Animal Health (Key Laboratory of Animal Immunology), Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China.
Institute for Animal Health (Key Laboratory of Animal Immunology), Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China.
Virology. 2025 May;606:110501. doi: 10.1016/j.virol.2025.110501. Epub 2025 Mar 13.
Senecavirus A (SVA) is an emerging swine virus with global prevalence that causes vesicular disease (VD), clinically similar to foot-and-mouth disease (FMD), posing a significant concern for the swine industry. The capsid protein VP2 is a structural protein of SVA, playing a critical role in mediating viral entry into host cells and inducing the production of neutralizing antibodies. In this study, the SVA VP2 protein was expressed using the Bac-to-Bac baculovirus expression system. Six monoclonal antibodies (mAbs) targeting SVA VP2 protein were then produced by immunizing mice with the recombinant VP2 protein, named as 1A1F6, 3D5F9, 3E2C3, 5A6F5, 5F12D10 and 7H10C3, respectively. Among these, mAbs 1A1F6 and 7H10C3 exhibited neutralizing activity against SVA in vitro with IC values of 0.64 μg/mL and 1.21 μg/mL, respectively. Finally, a linear B-cell neutralizing epitope of SLQELN on the SVA VP2 protein was identified by determining the reactivity of the neutralizing mAbs with the truncated VP2 protein followed by peptide scanning. Peptide mutation analysis showed that the residues Ser, Leu, Leu, and Asn within the epitope were essential for antibody binding. Multiple sequence alignment indicated that this epitope is highly conserved across various SVA strains. These findings provide a foundation for further studies on SVA and offer valuable support for the design of SVA vaccines.
A组马兜铃病毒（SVA）是一种在全球流行的新兴猪病毒，可引起水疱病（VD），临床上类似于口蹄疫（FMD），给养猪业带来了重大担忧。衣壳蛋白VP2是SVA的一种结构蛋白，在介导病毒进入宿主细胞和诱导中和抗体产生方面起着关键作用。在本研究中，使用杆状病毒表达系统表达了SVA VP2蛋白。然后用重组VP2蛋白免疫小鼠，产生了六种靶向SVA VP2蛋白的单克隆抗体（mAb），分别命名为1A1F6、3D5F9、3E2C3、5A6F5、5F12D10和7H10C3。其中，mAb 1A1F6和7H10C3在体外对SVA表现出中和活性，IC值分别为0.64μg/mL和1.21μg/mL。最后，通过测定中和单克隆抗体与截短的VP2蛋白的反应性，然后进行肽扫描，确定了SVA VP2蛋白上SLQELN的线性B细胞中和表位。肽突变分析表明，表位内的丝氨酸、亮氨酸、亮氨酸和天冬酰胺残基对于抗体结合至关重要。多序列比对表明，该表位在各种SVA毒株中高度保守。这些发现为进一步研究SVA提供了基础，并为SVA疫苗的设计提供了有价值的支持。
