Immunology of leishmaniasis.
Resolution of leishmanial infections requires the expansion of specific type 1 T helper cells that secrete or express on their membrane lymphokines capable of activating macrophages that contain these parasites to a microbicidal state. Specific CD8+ T cells, which are triggered during infection, also appear to play a role in protective immunity, possibly through their ability to secrete interferon-gamma. In the mouse model of infection with Leishmania major, the expansion of specific type 2 T helper cells exacerbates disease, an effect that appears to result from the properties of type 2 T helper derived lymphokines to deactivate macrophages and inhibit release of activating cytokines by type 1 T helper cells. In the mouse, destruction of intracellular Leishmania by activated macrophages depends upon the L-arginine-dependent production of nitrogen oxides. Molecules from the parasite that can induce, and are the target of, the protective T-cell response are being characterized.
Department of Medicine and Microbiology, University of California, San Francisco Medical Centre 94143-0654.
R M
RM
Locksley
J A
JA
Louis
D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D004195:Disease Models, Animal; D007111:Immunity, Cellular; D007895:Leishmania tropica / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology*; D008262:Macrophage Activation / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains
D000953:Antigens, Protozoan; D016207:Cytokines