Expressions of Bovine IFN-gamma and foot-and-mouth disease VP1 antigen in P. pastoris and their effects on mouse immune response to FMD antigens.

As a highly contagious disease in cloven-hoofed animals, foot-and-mouth disease virus (FMDV) may cause a considerable social-economic loss in those countries affected. IFN-gamma has a wide range of antiviral and immune modulating functions. Thus, to study the immune enhancing effects of recombinant Bovine IFN-gamma (rBoIFN-gamma) on a recombinant FMDV vaccine, BoIFN-gamma, FMDV VP1 and BoIFN-gamma/VP fusion genes were cloned, expressed, co-expressed in pichia pastoris (P. pastoris) respectively, and subsequent immune effects have been evaluated in this study. The results showed that the genes encoding for BoIFN-gamma, VP1 and BoIFN-gamma/VP1 are successfully expressed in P. pastoris and their products are directly secreted into the cultural supernatant at a high level of 1.0 g/L analyzed by thin-layer scanning. In addition, rVP1 alone could induce both humoral and marginal cell-mediated immune responses in mice, while the group with co-inoculations of rBoIFN-gamma could markedly enhance both humoral and cell-mediated immune responses; even more dramatic immune responses were observed with the group inoculated with the fusion product, rBoIFN-gamma/VP1. The fusion product could be further investigated for its utility of FMDV vaccine development.