Enhanced immunogenicity of multiple-epitopes of foot-and-mouth disease virus fused with porcine interferon alpha in mice and protective efficacy in guinea pigs and swine.

Foot-and-mouth disease (FMD) is a highly contagious and economically devastating vesicular disease of cloven-hoofed animals. In this study, three amino acid residues 21-60, 141-160 and 200-213 from VP1 protein of FMDV were selected as multiple-epitopes (VPe), and a recombinant adenovirus expressing the multiple-epitopes fused with porcine interferon alpha (rAd-pIFN alpha-VPe) was constructed. Six groups of female BALB/c mice (18 mice per group) were inoculated subcutaneously (s.c.) twice at 2-week intervals with the recombinant adenoviruses and the immune responses were examined. Following this the protective efficacy of rAd-pIFN alpha-VPe was examined in guinea pigs and swine. The results showed that both FMDV-specific humoral and cell-mediated immune responses could be induced by rAd-VPe and increased when rAd-pIFN alpha is included in this regime in mice model. Moreover, the levels of the immune responses in the group inoculated with rAd-pIFN alpha-VPe were significantly higher than the group inoculated with rAd-VPe plus rAd-pIFN alpha. All guinea pigs and swine vaccinated with rAd-pIFN alpha-VPe were completely protected from viral challenge. It demonstrated that recombinant adenovirus rAd-pIFN alpha-VPe might be an attractive candidate vaccine for preventing FMDV infection.