Identification of three new type-specific antigen epitopes in the capsid protein of porcine circovirus type 1

Porcine circovirus type 1 (PCV1) has been identified as a contaminant of porcine kidney cell line (PK-15). Serological evidence and genetic studies have suggested that PCV1 is widespread in domestic pigs. In this study, monoclonal antibodies (mAbs) and polyclonal antibodies (pAbs) were generated against a recombinant PCV1 Cap protein (PCV1-Cap), which was expressed using the baculovirus system. PEPSCAN analysis was used to identify epitopes on the PCV1-Cap with mAbs and pAbs. Three linear B-cell epitopes, including residues 85GGTNPLP91, 162FTPKPELDKTIDWFHPNNK180 and 219YVQFREFILKDPLNK233, specific for PCV1-Cap, were finely defined. These results will facilitate future investigations into antigenic differences and differential diagnosis between PCV1 and PCV2.