Screening and identification of linear B-cell epitopes on structural proteins of African Swine Fever Virus

This study aims to screen and identify linear B-cell epitopes on the structural proteins of African Swine Fever Virus (ASFV) to assist in the development of peptide-based vaccines. In experiments, 66 peptides of 12 structural proteins of ASFV were predicted as potential linear B-cell epitopes using bioinformatics tools and were designed; the potential epitope proteins carried the GST tag were expressed, purified, and subjected to antigenicity analysis with porcine antiserum against ASFV, and further identified based on their immunogenicity in mice. A total of 22 potential linear B-cell epitopes showed immunoreactivity and immunogenicity. Of these epitopes, 13 epitopes were firstly identified including 4 epitopes located in p72 (352-363, 416-434, 424-439, 496-530 aa), 3 epitopes located in pE248R (121-136, 138-169, 158-185 aa), and only one epitope of each protein of pH108R (33-46 aa), p17 (63-86 aa), pE120R (65-117 aa), pE199L (175-189 aa), p12 (36-56 aa) as well as pB438L (211-230 aa). Notably, the immunoreactivity of the epitopes from the 63-86 aa of p17 and the 65-117 aa of pE120R were the highest amongst identified epitopes, while the immunogenicity of epitopes from the 36-56 aa of p12, the 211-230 aa of pB438L, the 352-363 aa of p72 and the 63-86 aa of p17 were the best strong. The other 9 epitopes are partly overlapped with previous researches. These epitopes identified here will further enrich the database of ASFV epitope, as well as help to develop safe, effective epitope-based ASF vaccines and ASF diagnostic reagents.