In vitro proliferation of lymphocytes from human volunteers vaccinated with armadillo-derived, killed M. leprae.
A killed, armadillo-derived Mycobacterium leprae vaccine was examined for its ability to induce cell-mediated responsiveness in purified protein derivative (PPD)-positive volunteers residing in a nonendemic country using the lymphocyte transformation test (LTT). A marked increase in the proliferative responses to a M. leprae-soluble antigen preparation was observed in the two groups which were vaccinated with the highest doses of the vaccine, i.e., 1.5 X 10(8) and 5 X 10(8) bacilli. This increase was observed in both groups 3 months after vaccination, and persisted for the study period of 1 year. The in vitro proliferative responses to whole bacilli, of both armadillo and human origin, showed a similar but smaller increase 3 months after vaccination. Some enhancement of responses to cross-reactive antigens, such as PPD, and to unrelated antigens such as streptokinase-streptodornase, tetanus toxoid and diphtheria toxoid, was also observed. Thus, the LTT revealed that while the killed M. leprae vaccine induced a specific cell-mediated response to M. leprae, it was also responsible for a nonspecific immune-enhancement effect in healthy volunteers.
D000328:Adult; D000818:Animals; D001135:Armadillos; D001428:Bacterial Vaccines / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007918:Leprosy / Q000517:prevention & control*; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D009166:Mycobacterium leprae / Q000276:immunology*; D014611:Vaccination
D001428:Bacterial Vaccines