The cellular immune response and protective efficacy against tuberculosis infection of a novel mycobacterium tuberculosis DNA vaccine p846 / 实用医学杂志

ABSTRACT

Objective To construct a novel M.tb DNA vaccine (p846) co-expressing mycobacterial triple antigens including Rv3615c, Mtb10.4 and Rv2660c, and evaluate its cellular immune response and protective efficacy against tuberculosis infection in BALB/c mice. Methods We constructed the p846 by using the cloning technology. The 6- to -8-week old female BALB/c mice were randomly divided into 4 groups p846, pcDNA3.1, PBS and the BCG group. All mice were administrated intramuscularly with 50 μg recombinant plasmids at 0, 2, 4, 6 week. A single dose of BCG was injected subcutaneously in the BCG group. Two weeks after the final immunization, 10 mice in each group were used for cell proliferation, ELISPOT and FCM assay, BCG challenge experiment and HE staining of lung were performed at 4, 6 weeks later, respectively. Results The p846 vaccine could effectively induce the specific T cell proliferation(P < 0.001) and increase the numbers of IFN-γ+T cells(P <0.001), compared with those in the PBS group and the vector conreol group. The mouse lung tissue presented very mild lung inflammation in the p846 group, compared with other groups. Conclusion Vaccine p846 could not only induce strong cellular immune response, but also efficiently protect BALB/c mice against M.tb infection.