Identification of T-cell-activating recombinant antigens shared among three candidate antileprosy vaccines, killed M. leprae, M. bovis BCG, and mycobacterium w.

Antigenic crossreactivity among three candidate antileprosy vaccines, killed Mycobacterium leprae, BCG, and Mycobacterium w, was studied using T-cell lines and clones raised from BCG- and killed-M. leprae-vaccinated subjects. To identify the crossreactive antigens, the T-cell lines and clones were tested against Escherichia coli lysates containing 65-, 36-, 28-, 18-, and 14-kilodalton (kDa) and 13B3 M. leprae antigens and 65-, 19-, and 12-kDa M. tuberculosis antigens. The short-term T-cell lines, which compared to T-cell clones are easy to raise and maintain, were equally effective in identifying the T-cell-activating recombinant antigens. The reactivity pattern of the T-cell lines and the clones suggested that 65-kDa M. leprae and M. tuberculosis antigens are present in M. leprae, BCG, and Mycobacterium w; 18-kDa M. leprae antigen is shared between M. leprae and Mycobacterium w, 13B3 M. leprae antigen is possessed by M. leprae and BCG. These and other unidentified T-cell-activating antigens shared among candidate leprosy vaccines may be the basis for induction of in vivo sensitization to M. leprae antigens after vaccination with BCG or Mycobacterium w.