Displaying epitope B and epitope 7 of porcine reproductive and respiratory syndrome virus on virus like particles of porcine circovirus type 2 provides partial protection to pigs

The Cap of porcine circovirus type 2 (PCV2) can be assembled into virus like particles (VLPs) in vitro that have multiple loops located on the particle surface. This would make it a good vehicle for displaying exogenous proteins or epitopes. We derived two epitopes, epitope B (EpB, S37HIQLIYNL45) and 7 (Ep7, Q196WGRL200) from Gp5 highly pathogenic reproductive respiratory syndrome (HP-PRRSV). replaced core region Loop CD (L75PPGGGSN82) carboxyl terminus (K222DPPL226) PCV2 Cap, respectively, to construct bi-epitope chimeric Cap. Its immunogenicity protective effects were evaluated as one PRRSV subunit vaccine. was soluble, efficiently expressed an Escherichia coli expression system, could self-assembled (cVLPs) with diameter 12–15 nm. Western blotting confirmed cVLPs specifically recognized by anti-PCV2, anti-EpB anti-Ep7 antibodies. vaccine alleviate clinical symptoms reduce viral loads after HP-PRRSV challenge 100–120 days old pigs. These data suggest provide pigs partial protection against homologous strains, provides new design additional vaccines.