A bicistronic DNA vaccine containing gene of FMDV and bovine IFN- alpha can prime humoral and cellular immune responses of guinea pigs.

摘要

This study was conducted to evaluate the immunogenicity and protective efficacy of a DNA vaccine against foot-and-mouth disease virus (FMDV). Genes encoding the P1, 2A, 3C of FMDV 0/China99 and bovine IFN- alpha were cloned into pcDNA3.1 (+) expression vector under CMV promoter and FMDV IRES control, respectively. The recombinant plasmids were administered to guineapigs by intramuscular injection with mono- or bicistronic expression plasmids and aurintricarboxylic acid (ATA). After 2 sequential vaccinations with plasmid DNA, all of guineapigs were challenged with 100 ID50 FMDV 0/China99. Anti-FMDV antibodies were detected by ELISA and neutralization assay, and the phenotyping of T-cell subpopulation in the peripheral blood were performed by flow cytometry. Vaccination of guinea pigs with mono- or bicistronic expression plasmids induced humoral and cellular immune responses to FMDV antigens. In the challenge test, some of the animals were protected against the challenge of a virulent virus. This study demonstrates that the delivery of FMDV antigens via bicistronic vectors is feasible. Further experimentation with bicistronic delivery systems is required for the optimization and refinement of DNA vaccines to effectively prime protective immune responses against foot-and-mouth disease (FMD).