Studies on the antigenic specificity of Mycobacterium leprae. II. Immunological characterization.

Antigens from untreated and autoclaved Mycobacterium leprae obtained through chromatofocusing were tested for their ability to both induce as well as elicit skin reactivity in guinea pigs sensitized either with homologous and heterologous mycobacteria or with the fractions derived from autoclaved M. leprae. In former studies, of the several antigen-positive fractions, one showed specific activity and the remaining others cross-reactivity, as indicated by studies of hypersensitivity. The fraction exhibiting specificity contained only one antigen, whereas the other fractions contained more than one antigen. Because of the technique employed, all the fractions contained antigens that were proteinic in nature. In the latter studies, the antigens obtained from autoclaved M. leprae were shown to possess sensitizing capabilities, in addition to induction properties. Two fractions from untreated M. leprae had antigens that were heat-labile, whereas the remaining fractions contained heat-stable antigens.