Identification of an immunodominant antigen of mycobacterium leprae and its application for the development of protective measure

Abstract

Host defense against Mycobacterium leprae (M. leprae) is chiefly conducted by cellular immunity. The adaptive immunity plays an important role, and T cells are activated through recognition of some immunodominant antigens of M. leprae. A search for an immunodominant antigen was carried out using human peripheral monocytes-derived dendritic cells and M. leprae-derived cell membrane fraction which is the most antigenic fraction of the bacteria, and Major Membrane Protein (MMP)-II was found as one of the immunodoninant antigens.The MMP-II highly stimulated both dendritic cells and macrophages to produce various cytokines. Further, MMP-II was recognized by T cells in vivo in patients infected with M. leprae. Then, we constructed a recombinant BCG secreting MMP-1I. The recombinant BCG strongly stimulated both naive CD4+and naive CD8+cells, and seemed to be a useful immunostimulatory agent.