Nitric oxide‐mediated suppression of T cell responses during Trypanosoma brucei infection: soluble trypanosome products and interferon‐γ are synergistic inducers of nitric oxide synthase

摘要: African trypanosome infections result in lymphocyte unresponsiveness and anemia the mammalian host. In murine infections, these effects are mediated by suppressor macrophages releasing nitric oxide (NO). We investigated mechanism of activation to produce NO during trypanosomiasis vitro. A soluble component lysates induced synthesis peritoneal macrophage cultures only when were co-stimulated with interferon-gamma (IFN-γ). The macrophage-activating factor was also released a form live bloodstream-form trypanosomes, but not procyclic trypanosomes. When splenocyte exposed IFN-γ an NO-dependent suppression T cell proliferation occurred. This is similar observed spleens trypanosome-infected mice, suggesting that combination trypanosome-released factors trigger immune dysfunction trypanosomiasis.