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

Abstract

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.