Relative contribution of interferon-γ and interleukin-10 to resistance to murine African trypanosomosis

Abstract

Resistance to Trypanosoma brucei brucei has been correlated with the ability of infected animals to produce interferon (IFN)-γ and tumor necrosis factor (TNF) in an early phase of infection, followed by interleukin (IL)-4 and IL-10 in late and chronic stages of the disease. Contributions of IFN-γ and IL-10 in the control of parasitemia and survival of mice infected with T. brucei brucei were investigated by using IFN-γ-/-and IL-10-/-mice. Results suggest that IFN-γ, mainly secreted by CD8+T cells, is essential for parasite control via macrophage activation, which results in TNF and nitric oxide secretions. IL-10, partially secreted by CD4+T cells, seems to be important for the survival of infected mice. Its absence resulted in the sustained secretion of inflammatory mediators, which indicated the role of IL-10 in maintaining the balance between pathogenic and protective immune responses during African trypanosomosis.