Mycobacterium indicus pranii protein MIP_05962 induces Th1 cell mediated immune response in mice.

Utility of Mycobacterium indicus pranii (MIP) as a multistage vaccine against mycobacterial infections demands identification of its protective antigens. We explored antigenicity and immunogenicity of a candidate protein MIP_05962 that depicts homology to HSP18 of M. leprae and antigen1 of Mycobacterium tuberculosis. This protein elicited substantial antibody response in immunized mice along with modulation of cellular immune response towards protective Th1 type. Both CD4 and CD8 subsets from immunized mice produced hallmark protective cytokines, IFN-γ, TNF-α and IL-2. This protein also enhanced the CD4 effector memory that could act as first line of defence during infections. These results point to MIP_05962 as a protective antigen that contributes, in conjunction with others, to the protective immunity of this live vaccine candidate.