Mycobacterium leprae-specific Lyt-2+ T lymphocytes with cytolytic activity.
Mice were immunized intradermally with 10(7) irradiated Mycobacterium leprae organisms, and draining lymph nodes were collected after 4 weeks. Lymph node cells were restimulated in vitro with soluble M. leprae antigen and accessory cells. The resulting T-cell line was propagated in vitro in the presence of M. leprae antigen, accessory cells, and interleukin-2-containing supernatants from concanavalin A-stimulated rat spleen cells. Long-term cultured T cells were Thy-1+ L3T4- Lyt-2+ as revealed by analysis with the fluorescence-activated cell sorter. From this line, T-cell clones with the same phenotype were established. The T-cell clone A4 failed to secret interleukin-2 after stimulation with antigen and accessory cells, and its growth depended on exogeneous interleukin-2. A4 T cells produced gamma interferon in an antigen-specific, H-2-restricted, and interleukin-2-dependent way. Importantly, this T-cell clone was capable of lysing bone marrow macrophages presenting M. leprae antigen. Other T-cell clones as well as native Lyt-2+ T cells from M. leprae-immunized mice were also capable of lysing bone marrow macrophages expressing M. leprae antigens. These findings suggest that specific Lyt-2+ T cells participate in the immune response to M. leprae. It is postulated that cytolysis of M. leprae-infected macrophages or Schwann cells contributes to protection against and pathogenesis of leprosy.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly / Q000276:immunology*; D000954:Antigens, Surface / Q000032:analysis; D001854:Bone Marrow Cells; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D006183:H-2 Antigens / Q000276:immunology; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000096:biosynthesis; D008198:Lymph Nodes / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D009166:Mycobacterium leprae / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000942:Antigens, Bacterial; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D000954:Antigens, Surface; D006183:H-2 Antigens; D007371:Interferon-gamma