Identification Epitope on VP4 Protein of Senecavirus A Recognized by a Monoclonal Antibody

Senecavirus A (SVA) is a causative agent of vesicular disease in pigs and has gained global attention in recent years. SVA infection leads to vesicular lesions and hoof deformities in pigs, posing a significant threat to the swine industry. The VP4 protein is a crucial component of the SVA capsid, located on the inner surface of the virus particle, and plays a key role in the viral life cycle. However, its exact function and immunological characteristics remain poorly understood. Additionally, the VP4 protein of picornaviruses is known to form antigenic epitopes during viral infection, providing potential targets for antibody development and vaccine design. Nevertheless, due to the unique location of VP4, these epitopes remain largely unexplored. In this study, a monoclonal antibody (mAb) 4E4 was successfully generated by immunizing mice with purified SVA VP4 protein. The mAb 4E4 specifically recognizes recombinant VP4 protein and the SVA‐infected cells. Further epitope mapping using truncated VP4 proteins detected with Western blotting defined a key B‐cell epitope, 7 SKDNFD 12 , which is exposed on the surface of VP4 protein and is highly conserved among different SVA strains. Additionally, mAb 4E4 showed neutralizing activity against SVA. This study provides the first identification of a conserved antigenic epitope on the SVA VP4 protein. This finding provides valuable tools for further investigation of VP4 protein function and lays the foundation for developing novel diagnostic and vaccine strategies.