口蹄疫多表位重组蛋白在大肠杆菌中的可溶性表达及其免疫效果评价OA

Foot-and-mouth disease(FMD),caused by the Foot-and-mouth disease virus(FMDV),is a highly contagious disease among cloven-hoofed animals,posing a serious threat to the development of the livestock industry.In order to develop a novel epitope vaccine for FMD,this study,based on the gene sequence of the prevalent swine(Sus scrofa)O-type FMDV strain(O/MYA98/BY/2010),constructed a recombinant expression plasmid pColdⅡ-7B2T containing 7 B-cell epitopes and 2 T-cell epitopes.The recombinant plasmid was co-expressed with the molecular chaperone TF16 in Escherichia coli,followed by a series of analytical procedures including affinity purification,SDS-PAGE,and Western blot analysis.The recombinant protein was then used to immunise BALB/c mice(Mus musculus),after which its humoral and cellular immune responses were evaluated.The results demonstrated that the 7B2T recombinant protein,prepared using the molecular chaperone TF16,was expressed in a soluble form with a molecular weight of approximately 26 kD and could induce a specific immune response with FMDV-positive serum.Furthermore,the 7B2T protein was found to induce significant specific IgG production in the host,with an average neutralising antibody titer of 1∶96.In addition,the 7B2T protein had been observed to induce robust cellular immune responses in murine models,promoting the differentiation of CD4+and CD8+T lymphocyte subsets within the spleen.Lymphocyte proliferation assays and enzyme-linked immunospot assays(ELISPOTS)revealed that the splenic lymphocyte proliferation levels and interferon-γ(IFN-γ)spot counts in the 7B2T protein-treated group were extremely significantly higher than those in the inactivated vaccine(IV)group and PBS group(P＜0.01),while the IL-4 spot counts were comparable to those of the IV group.In summary,the present study demonstrated that the soluble multi-epitope 7B2T recombinant protein,prepared using the molecular chaperone TF16,was capable of inducing both humoral and cellular immune responses in mice.This study provides experimental ideas and data references for the preparation of FMD multi-epitope recombinant proteins and the development of multi-epitope vaccines.