Immunoprophylaxis of recombinant Mycobacterium vaccae secreted MPT64 of Mycobacterium tuberculosis

AIM To evaluate immunoprophylaxis of recombinant Mycobacterium vaccae secreted MPT64 of Mycobacterium tuberculosis. METHODS BALB/c mice were immunized with recombinant Mycobacterium vaccae secreted MPT64 of Mycobacterium tuberculosis. ELISA was used to detect the anti-MPT64 antibody titers and subtype in immunized mice sera. Splenocytes of immunized mice were separated and used to detect IFN-gamma and IL-12 levels, splenocytic proliferation, counts of CD4(+) and CD8(+) T cell percentage, cytolytic T lymphocyte specific lysis. The bacteria numbers in vaccination animal's lung and spleen were counted by colony forming units (CFUs) on plate. RESULTS Recombinant Mycobacterium vaccae secreted MPT64 of Mycobacterium tuberculosis could induce high level of specific IgG antibodies, stronger T cell proliferation response, production of IFN-gamma and IL-12, CD4(+) and CD8(+) cell percentages and CTL effect in mice. And an efficacy protection against Mycobacterium tuberculosis was also observed in mice model. CONCLUSION Recombinant Mycobacterium vaccae secreted MPT64 could induce high level humoral and cell mediated immune responses in mice and could be used as a candidate of new vaccine against TB.