Preparation and preliminary application of a monoclonal antibody against the African swine fever virus D205R protein

Abstract Background African swine fever (ASF) is a lethal infectious disease that causes significant economic losses to the pig industry worldwide. However, few vaccines or drugs were available to prevent or control ASF to date. The D205R protein (pD205R) is a non-structural protein of the African swine fever virus (ASFV) that is abundantly expressed in virus-infected macrophages. However, the antigenic epitopes of pD205R remain unclear. Results The main aim of this study was to investigate the new antigenic epitope of pD205R, providing a new tool for the prevention and diagnosis of ASF. Recombinant pD205R was firstly expressed with prokaryotic system and purified with Ni affinity chromatography. Hybridoma cell fusion, clone purification, and immunological assays were then used to develop a monoclonal antibody (mAb) against pD205R. Alanine scanning indicated that S167, W173, L174, G175, P178, and D180 were important for binding to mAb 19A5, and homologous and structural analysis revealed that these residues were highly conserved across all assessed ASFV strains and located on the protein surface. Conclusion The results of this study are expected to provide new insights into the development of vaccines and the establishment of serological diagnostic methods for ASF.