title: Immunosuppression associated with visceral leishmaniasis of hamsters.
abstract: Immunosuppression was demonstrated during the course of Leishmania donovani infection of outbred and inbred hamsters. Proliferative responses of splenic lymphocytes to the mitogen concanavalin A (Con A) and to promastigote antigens were used as indicators of immune responsiveness. Although splenic lymphocyte proliferative responses to parasite antigens were demonstrable 3 weeks after challenge, antigen specific lymphocyte responses diminished as the infection progressed. Two types of immunosuppression were demonstrable. The first was a non-specific anergy of splenic lymphocytes to Con A stimulation. Thus, spleen cells from infected animals did not actively suppress the Con A responses of normal lymphocytes in mixed cultures A second immunosuppression mechanism, specific for leishmania antigens was mediated by a nylon wool non-adherent cell population. The suppressor, tentatively identified as a T cell population, inhibited the proliferation of parasite antigen sensitized responder lymphocytes in mixed culture. Elimination of the parasite burden by glucantime therapy restored responsiveness of lymphocytes to parasite antigens. Con A responses, however, remained suppressed 1 week after drug cure.
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D000965:Antimony / Q000627:therapeutic use; D006224:Cricetinae; D007108:Immune Tolerance; D007891:Leishmania / Q000276:immunology; D007898:Leishmaniasis, Visceral / Q000188:drug therapy / Q000276:immunology*; D008213:Lymphocyte Activation; D008536:Meglumine; D000077485:Meglumine Antimoniate; D008647:Mesocricetus; D009942:Organometallic Compounds; D013997:Time Factors
chemical_list: D000953:Antigens, Protozoan; D009942:Organometallic Compounds; D008536:Meglumine; D000077485:Meglumine Antimoniate; D000965:Antimony