Single immunization with a recombinant multiple-epitope protein induced protection against FMDV type Asia 1 in cattle.

To develop recombinant epitope vaccines against the foot-and-mouth disease virus (FMDV) serotype Asia 1, genes encoding six recombinant proteins (A1-A6) consisting of different combinations of B-cell and T-cell epitopes from VP1 capsid protein (VP1) of FMDV were constructed. These proteins were expressed in Escherichia coli and used to immunize animals. Our results showed that A6 elicited higher titers of neutralizing antibodies after single inoculation in guinea pigs than did the other five recombinant proteins, as determined by micro-neutralization tests. In addition, a strong lymphocyte proliferation response and Th1 type immunity were observed in splenocytes from the mice immunized with A6. Further tests carried out in cattle demonstrated that a single inoculation with A6 generated comparable levels of neutralizing antibodies as inactivated vaccine and protected 4 of 5 cattle against challenge with FMDV type Asia 1. Our results suggest that A6 might be a promising recombinant vaccine against FMDV type Asia 1 in cattle.