结核分枝杆菌Rv1626的原核表达及其免疫功能研究

结核分枝杆菌；Rv1626；原核表达；免疫原性；结核病

Prokaryotic Expression and Immune Function of Mycobacterium Tuberculosis Rv1626

Objective To target the secretory antigen Rv1626 after Mycobacterium tuberculosis (M.tb) infection, construct its prokaryotic expression plasmid pPROEX-Rv1626 and express it for purification. The immunogenicity was evaluated by human and animal experiments. Methods The recombinant vector pPROEX-Rv1626 was constructed and tested by whole blood interferon release assay (WBIA) to detect T cells specifically recognized by M.tb infected patients in Changzhi City, Shanxi Province. Simultaneous immunization of mice was used to detect their specific induction. The levels of IFN-γ, TNF-α and IL-2 secreted by spleen cells and antibody levels. Results ①The recombinant vector pPROEX-Rv1626 was successfully constructed and successfully expressed, purified and identified. ②rRv1626 protein induced IFN-γ levels in peripheral blood of M.tb infected patients was significantly higher than healthy controls (P<0.0001). At the same time, the level of IFN-γ secreted by lymphocytes in peripheral blood of ATB patients was significantly higher than that of LTBI (P<0.0005);③The specific antibody titers produced by BCG+Rv1626/DMT group were significantly higher than those of Rv1626/DMT group and BCG group (P<0.01).The ratio of IgG2a/IgG1 in Rv1626/DMT group and BCG+Rv1626/DMT group was significantly higher than that in DMT group and BCG group (F=33.69), and the former two groups of IgG2a/IgG1>1 tended to Th1 type cellular immune response; ④Different The mice in the immunized group were stimulated with PPD or rRv1626 protein, and the highest levels of IL-2, IFN-γ and TNF-α were secreted in the BCG+Rv1626/DMT group, followed by the BCG group and the Rv1626/DMT group, and the PBS group was the lowest. At the same time, the Rv1626/DMT group was significantly higher than the DMT group (P<0.005). Conclusion rRv1626 can be recognized by T cells infected by M.tb. Immunized mice can induce antigen-specific Th1-type cellular immune responses, which may be closely related to the immune protection provided by them.