Objective:The eukaryotic expression plasmid pVAXⅠ-P1-2A containing capsid protein precursor P1-2A gene of Asia-ⅠFMDV was constructed. Cellular and humoral immunity level of the mice immunized against pVAXⅠ-P1-2A was evaluated. Methods:The gene of FMDV P1-2A was amplified by RT-PCR, inserted into vector pMD18-T, then subcloned to eukaryotic expression vector pVAXⅠ. The eukaryotic expression plasmid pVAXⅠ-P1-2A transfected into the Hela cell, and detected by IFA. The mice were immunized against pVAXⅠ-P1-2A, the FMDV specific antibody was detected by ELISA, T lymphocyte proliferation analyzed by MTT, IFN-γ was detected by ELISPOT method. Results:The result of restriction endonuclease digestion was accordance with the anticipated objective strap size. IFA showed that there are flavovirens fluorescence in cells transfected with pVAXⅠ-P1-2A, and confirmed the expression of P1-2A gene in HeLa cell. The indirect ELISA test manifested that the antibody level was higher remarkably than the control groups (P0.05) in the 14th day after immunity, and more T lymphocyte and the cells that produce IFN-γ in immunized mice than the control groups (P0.05).The result showed that there are significant cellular and humoral immunity response in the mice immunized with pVAXⅠ-P1-2A. Conclusion: Eukaryotic expression plasmid pVAXⅠ-P1-2A was successfully constructed, and pVAXⅠ-P1-2A could induce specific humoral and cellullar immunity response in mice.

Objective: To construct polyvalent foot-and-mouth disease virus (FMDV) DNA vaccine and determine its immunogenicity. Methods: Polyvalent FMDV DNA vaccine pIRES-OAAT-PI-2A-3C was constructed based on complex poly-epitope expression cassette OAAT and P1-2A-3C gene of FMDV type Asia I and transfected to HeLa cells. Identify the expressed target protein by IFA. Immunize mice with pIRES-OAAT-P1-2A-3C, and determine the serum antibody by ELISA, the secretion of IFN-γ by splenic lymphocytes by ELISPOST, the number of splenic T lymphocyte subgroups by flow cytometry, and the proliferation level of specific lymphocytes by lymphocyte transformation test. Results: The constructed polyvalent FMDV DNA vaccine was correctly expressed in HeLa cells. The serum specific antibody level, secretion level of IFN-γ by splenic lymphocytes, the number of splenic T lymphocyte subgroups and the proliferation level of specific lymphocytes of mice after immunization with the DNA vaccine increased significantly. Conclusion: Polyvalent FMDV DNA vaccine was successfully constructed and induced specific cellular and humoral immune responses in mice.