title: Interleukin 2 deficiency in murine Leishmaniasis donovani and its relationship to depressed spleen cell responses to phytohemagglutinin.
abstract: This study examined the kinetics and mechanisms of depressed spleen cell responses to phytohemagglutinin (PHA) that occur during Leishmania donovani infection of BALB/c mice. In co-culture experiments, neither spleen cells from infected animals nor parasite-infected macrophages suppressed PHA responses of normal spleen cells. In addition, parasite-mediated suppression of PHA-stimulated spleen cell proliferation could not be demonstrated. Mice with 2 wk of infection did manifest an impairment in spleen cell production of interleukin 2 (IL 2) and by 8 wk IL 2 activity in supernatants from these cells was reduced by approximately 95%. This finding was not explained by an alteration in the kinetics of IL 2 production. Furthermore, diminished IL 2 activity in supernatants of PHA-activated spleen cells from infected animals was not caused by suppressive factors in these fluids as shown by their inability to suppress IL 2 stimulation of IL 2-dependent T cells. When spleen cells from mice with 8 wk of infection were cultured with PHA and supplemented with exogenous IL 2, there was an approximately 48% increase in mitogenesis. These data indicate that abnormal PHA-induced spleen cell activation in BALB/c mice with L. donovani infection is associated with impaired production of IL 2. In addition, the observation that supplementation of spleen cells from infected mice with IL 2 resulted in partial reconstitution of the PHA response is consistent with a defect in IL 2 responsiveness.
mesh_terms: D000818:Animals; D006224:Cricetinae; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D007376:Interleukin-2 / Q000096:biosynthesis* / Q000502:physiology; D007700:Kinetics; D007898:Leishmaniasis, Visceral / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D008647:Mesocricetus; D051379:Mice; D008807:Mice, Inbred BALB C; D010835:Phytohemagglutinins / Q000494:pharmacology; D013154:Spleen / Q000166:cytology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D007376:Interleukin-2; D010835:Phytohemagglutinins