Monoclonal antibody preparation and linear epitope identification for the ASFV A151R protein

African Swine fever (ASF) is an acute, hemorrhagic infectious disease caused by the African swine fever virus (ASFV), posing a major threat to the global pig farming industry. ASFV is a complex DNA virus. Its non-structural protein, A151R, is a thioredoxin crucial for the replication and morphogenesis of ASFV. In this study, a monoclonal antibody (mAb) 3E5D6 against pA151R (A151R Protein) was prepared using cell fusion technology to gain deeper insight into the function of A151R during ASFV infection. Immunolabeling of pA151R with 3E5D6 mAb revealed its involvement in viral factory formation and its characteristic early expression during infection. However, the antibody exhibited no detectable neutralizing activity. Subsequently, the antigenic epitope ⁸⁴KIWSGEPR⁹¹ of 3E5D6 was identified using bioinformatic analysis and molecular biology techniques. Homology and structural analyses indicated that this amino acid sequence was highly conserved across pA151R of different strains and was located on the surface of the protein. Furthermore, the 87 S residue is a key site for 3E5D6 recognition of pA151R. This antibody will allow us to better characterize host-virus interactions and further our understanding of the pathophysiology of ASFV infection.