Effects Of Several Adjuvants On The Immunogenicity Of Recombinant Multi Epitope Antigen Of Foot-and-mouth Disease Virus Type O In Pig

Foot-and-mouth disease is a strong infectious disease caused by foot-and-mouth disease virus, it has a lot of rapid routes for disseminate infection, and has been popular in many countries and regions. Foot-and-mouth disease have posed great threat to the improvement of citizen life conditions and the stockbreeding development. Vaccines have been decisive in the prevention of foot-and-mouth disease, when it occursthe infected animals will be burned or buried directly rather than treatment. From the development of traditional inertial vaccine to new-type vaccines. By untiring efforts of the researchers from generation to generation, its aim is to make vaccines safer and efficient. Epitope-based vaccines provide a new strategy that is widely used for prophylactic and therapeutic application of foot-and-mouth disease.Serotype O is the most important serum type of foot-and-mouth disease virus, which is renowned for three representative strains are called O/HN/CHA/93, O/Mya/98 and O/Tibet/CHA/99, they seriously affected the development of pig industry. In order todevelop the broad-spectrum multi epitope vaccine to FMDV type O in pig, we designed and synthesized a tandem-repeated multiple-epitopes gene named RE, which based on residues 135-160 and 200-213 of VP1 of above three strains. At the same time, the swine immunoglobin G heavy constant region gene was cloned. By using the Bam H I, Eco R I, Hind III, Xho I sites, both genes were cloned into p ET-30a(+) vector in turn to form a recombinant plasmid p E-Ig G. The recombinant plasmid was transformed into Escherichia coli BL21(DE3) cells, a chimeric protein,named p E-Ig G-672, was induced by IPTG, what follows was Purification, identification and bioactivity characterization of the recombinant protein by SDS-PAGE electrophoresis and Western blotting. According to the results of identification, the recombinant gene was expressed correctly. Later, Immunizing mice with five different multiple-epitopes vaccines to FMDV type O in pig adjuvanted with ISA206, ISA201, IMS1313, 603, ISA61, each mice contain 50μg recombinant antigen. The specific antibody levels in mice were determined by ELISA, and using flow cytometry to measure the proliferation ability of lymphocytes, so as to compare the differences from five adjuvants in terms of facilitate the immune response.The results showed that the recombinant p E-Ig G-672 protein was expressed as a formation of inclusion body, and it can specially react with FMDV type O positive serum. The ISA201 adjuvant and 603 adjuvant has stronger immunologic adjuvant effect than other adjuvants because it could promote the proliferation of mouse lymphocyte and could generate high level specific antibody when it mixed with recombinant antigen to prepare FMDV type O multi-epitope vaccine. Accordingly, we can conclude from the results that ISA201 may be the optimal adjuvant of FMDV type O multi-epitope vaccine.