An immunodominant 30-kDa antigen of a candidate anti-leprosy vaccine,Mycobacterium w, shares T and B cell determinants withM. leprae andM. tuberculosis

Earlier we reported that vaccination of leprosy patients withMycobacterium w induces an immune response directed predominantly against low molecular weight antigens. One of these antigens, with a molecular mass of 30-kDa, was recognized by a majority of the vaccinated subjects as well as the tuberculoid leprosy patients and healthy contacts. In the present communication we report further characterization of this antigen. Immunofluorescence and Western blot studies with antibodies raised against this antigen demonstrate that it is associated with the cell surface and has homologues present inM. leprae andM. tuberculosis. Delayed-type hypersensitivity studies carried out in guinea pigs immunized with the 30-kDa antigen show that in addition to sharing B cell determinants, this immunodominant antigen ofM. w also shares T cell determinants withM. leprae andM. tuberculosis.