Leishmania: naive human T cells sensitized with promastigote antigen and IL-12 develop into potent Th1 and CD8(+) cytotoxic effectors.
Russo, D. M., Chakrabarti, P., and Higgins, A. Y. 1999. Leishmania: Naive human T cells sensitized with promastigote antigen and IL-12 develop into potent Th1 and CD8(+) cytotoxic effectors. Experimental Parasitology 93, 161-170. The differentiation of naive human T cells into Leishmania-specific Th1 or cytotoxic effector cells was examined by sensitizing T cells in vitro with dead Leishmania antigen in the presence or absence of IFN-gamma or IL-12. These Leishmania-specific T cell lines proliferated and produced cytokines in response to challenge with autologous Leishmania-infected macrophages. Sensitization in the presence of IL-12 or IFN-gamma induced Leishmania-specific human Th1 responses, with IL-12 inducing more potent Th1 responses. However, IL-12-induced Th1 responses were IFN-gamma dependent. T cell lines exhibited Th2 or Th0 phenotypes when primed in the absence of cytokines. Only T cell lines primed in the presence of IL-12 contained high percentages of CD8(+) cells. These cells lysed autologous Leishmania-infected but not uninfected macrophages in an MHC-dependent manner. Thus, this in vitro sensitization system can be used to delineate the conditions for optimally priming human Leishmania-specific effector cells.
Russo
D M
DM
Department of Microbiology, Meharry Medical College, Nashville, Tennessee 37208, USA.
Chakrabarti
P
P
Higgins
A Y
AY
D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology*; D015847:Interleukin-4 / Q000096:biosynthesis; D007891:Leishmania / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation; D008264:Macrophages / Q000469:parasitology; D018417:Th1 Cells / Q000276:immunology*
D000953:Antigens, Protozoan; D018664:Interleukin-12; D015847:Interleukin-4; D007371:Interferon-gamma