Murine spleen and lymph node cellular composition and function during cyclophosphamide and splenectomy induced resistance to Toxoplasma gondii.
Murine toxoplasmosis caused by a low virulence, cyst-forming strain of Toxcoplasma gondii (Pe strain) is characterized by splenomegaly, lymphadenopathy, decreased delayed-type hypersensitivity (DTH), and the presence of toxoplasma cysts in brain tissue. Cyclophosphamide (CY) in a single dose of 100 mg/kg injected 3 days before infection, or splenectomy 3 weeks before infection, augmented DTH and decreased the number of toxoplasma brain cysts. CY-induced augmentation of resistance during the first 3 weeks of murine toxoplasmosis was associated with: (1) an increase in mononuclear phagocytes and a decrease in T lymphocytes (including Lyt2+ cells) in spleens and lymph nodes; (2) suppressed toxoplasma antigen induced proliferation of cultured spleen cells: (3) augmentation of antigen induced proliferation of cultured lymph node cells; and (4) low levels of interferon-gamma production in both spleen and lymph node cultures. The best correlate of the enhanced in-vivo effects of CY was proliferation of nylon wool-purified lymph node cells to toxoplasma antigen. The presence of Lyt2+ cells in lymph nodes of toxoplasma infected mice inhibited maximal proliferation.
D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D001921:Brain / Q000469:parasitology; D003520:Cyclophosphamide / Q000494:pharmacology*; D006968:Hypersensitivity, Delayed; D007371:Interferon-gamma / Q000096:biosynthesis; D008198:Lymph Nodes / Q000276:immunology* / Q000473:pathology; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008808:Mice, Inbred CBA; D009929:Organ Size; D013154:Spleen / Q000276:immunology* / Q000473:pathology; D013156:Splenectomy; D014122:Toxoplasma / Q000276:immunology / Q000502:physiology; D014124:Toxoplasmosis, Animal / Q000276:immunology* / Q000469:parasitology / Q000473:pathology
D000953:Antigens, Protozoan; D007371:Interferon-gamma; D003520:Cyclophosphamide