Identification of a linear B-cell epitope on glycoprotein (GP) 2a of porcine reproductive and respiratory syndrome virus (PRRSV).

Abstract

Glycoprotein (GP) 2a was a minor structural protein of porcine reproductive and respiratory syndrome virus (PRRSV) and was one of crucial proteins for PRRSV to bind cell receptor, which indicated that there were neutralizing epitopes on GP2a. In the present work, we used mouse anti-GP2a41-208aa serum and one GP2a41-208aa specific monoclonal antibody (McAb) to identify B-cell epitopes of GP2a by peptide-based ELISA. A liner B-cell epitope F194PTPGSRPKLHDFQQ208 was identified. However, the results of virus neutralization experiment showed that the McAb could not reduce the titers of PRRSV, which indicated that the identified epitope was not the neutralizing epitope of PRRSV. While the amino acid sequence of this epitope was conserved in North American (type 2) PRRSV, which suggested that this epitope might be diagnostic potential for type 2 PRRSV strains. In conclusion, our present work identified a new epitope on GP2a and this epitope might be diagnostic potential for type 2 PRRSV strains.