Identification of a linear B-cell epitope on the "puff" loop of the Senecavirus A VP2 protein involved in receptor binding

Hanrong Zhou; Mingxia Sun; Shibo Su; Liang Meng; Wei Yang; Lan Yang; Xinqi Shi; Xin Li; Haiwei Wang; Hongwei Ma; Xuehui Cai; Yan-Dong Tang; Tongqing An; Fandan Meng

doi:10.3389/fmicb.2024.1387309

Identification of a linear B-cell epitope on the "puff" loop of the Senecavirus A VP2 protein involved in receptor binding

Front Microbiol. 2024 Apr 23:15:1387309. doi: 10.3389/fmicb.2024.1387309. eCollection 2024.

Authors

Hanrong Zhou^#¹, Mingxia Sun^#¹, Shibo Su^#¹, Liang Meng¹, Wei Yang², Lan Yang³, Xinqi Shi¹, Xin Li¹, Haiwei Wang¹, Hongwei Ma^{1

3}, Xuehui Cai^{1

4}, Yan-Dong Tang¹, Tongqing An^{1

5}, Fandan Meng¹

Affiliations

¹ State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, Heilongjiang, China.
² College of Veterinary Medicine, Northeast Agricultural University, Harbin, China.
³ Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.
⁴ Heilongjiang Research Center for Veterinary Biopharmaceutical Technology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.
⁵ Heilongjiang Provincial Key Laboratory of Veterinary Immunology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.

^# Contributed equally.

Abstract

Senecavirus A (SVA) is an important emerging swine pathogen that causes vesicular lesions in swine and acute death in newborn piglets. VP2 plays a significant role in the production of antibodies, which can be used in development of diagnostic tools and vaccines. Herein, the aim of the current study was to identify B-cell epitopes (BCEs) of SVA for generation of epitope-based SVA marker vaccine. Three monoclonal antibodies (mAbs), named 2E4, 1B8, and 2C7, against the SVA VP2 protein were obtained, and two novel linear BCEs, ¹⁷⁷SLGTYYR¹⁸³ and ²⁶⁶SPYFNGL²⁷², were identified by peptide scanning. The epitope ¹⁷⁷SLGTYYR¹⁸³ was recognized by the mAb 1B8 and was fully exposed on the VP2 surface, and alanine scanning analysis revealed that it contained a high continuity of key amino acids. Importantly, we confirmed that ¹⁷⁷SLGTYYR¹⁸³ locates on "the puff" region within the VP2 EF loop, and contains three key amino acid residues involved in receptor binding. Moreover, a single mutation, Y182A, blocked the interaction of the mutant virus with the mAb 1B8, indicating that this mutation is the pivotal point for antibody recognition. In summary, the BCEs that identified in this study could be used to develop diagnostic tools and an epitope-based SVA marker vaccine.

Keywords: B-cell epitopes (BCEs); Senecavirus A (SVA); VP2 protein; monoclonal antibodies (mAbs); receptor binding.

Grants and funding

The author (s) declare that financial support was received for the research, authorship, and/or publication of this article. This study was supported by grants from the National Science Foundation of China (grant number 32002249 to FM), the Heilongjiang Provincial Natural Science Foundation of China (No. LH2023C023 to WY), the National Key Research and Development Program of China (No. 2022YFD1800300 to TA), the Foundation of the National Research Center of Engineering and Technology for Veterinary Biologicals [No. GTKF (23)008 to FM], the Natural Science Foundation of Heilongjiang Province (No. ZD2023C005 to TA), the Key Research and Development Foundation of Heilongjiang Province (No. JD22A023 to TA), and the Innovation Program of the Chinese Academy of Agricultural Sciences (CAAS-CSLPDCP-202301 to TA).