LYMPHOSTIMULATORY AND DELAYED-TYPE HYPERSENSITIVITY RESPONSES TO A CANDIDATE LEPROSY VACCINE STRAIN - MYCOBACTERIUM HABANA

Lymphostimulatory and delayed-type hypersensitivity (DTH) immune respo nses to a candidate antileprosy vaccine Mycobacterium habana have been quantified in inbred AKR mice. M. habana vaccine in three physical st ates, live, heat-killed and gamma-irradiated, was given intradermally to separate groups of mice and after 28 days these mice were given sub cutaneous challenge with heat-killed M. leprae and heat-killed M. haba na in the left hind footpad. Live BCG vaccine alone and in combination with gamma-irradiated M. habana were also compared similarly. A suffi cient degree of DTH response was generated in mice by M. habana vaccin e in all physical forms against two challenge antigens (lepromin and h abanin). The BCG combination with M. habana did not increase the DTH r esponse indicating internal adjuvanticity endowed in M. habana. The ac tive hypersensitivity of immunized mice was transferable to syngeneic mice by the transfer of sensitized cells from the donor to the recipie nt mice intravenously. M. leprae-infected Rhesus monkey PBMC have show n comparable stimulatory response with M. habana (sonicate), and M. le prae (sonicate) antigens. The possibility of developing M. habana as a candidate antileprosy vaccine is discussed.