FIG 3.

The increased survival of CD8^−/− mice infected with T. brucei is abolished by anti-IL-10R treatment. (A) Groups of 5 CD4^−/− (open bars), CD8^−/− (hatched bars), or wild-type (filled bars) BALB/c mice were either infected with 10³ T. brucei VAT 10-26 parasites or left uninfected. Mice were killed on day 6 after infection, and plasma samples were collected. Spleen cells were collected and were cultured for 48 h. The amounts of IL-10 in plasma or supernatant fluids of spleen cultures were determined by ELISA. (B) Groups of 5 CD8^−/− (squares) or wild-type (circles) BALB/c mice were infected with 10³ T. brucei VAT 10-26 parasites and were treated with 200 μg of an anti-IL-10R MAb (open symbols) or rat IgG as a control (filled symbols) on days 3 and 5 after infection, respectively. Mice were monitored for parasitemia and survival. (C) Groups of 5 CD8^−/− (open bars) or wild-type (filled bars) BALB/c mice were infected with 10³ T. brucei VAT 10-26 parasites and were treated with 200 μg of an anti-IL-10R MAb or rat IgG as a control on days 3 and 5 after infection, respectively. Plasma samples were collected from the mice on day 6 after infection. Levels of IFN-γ and IL-10 in plasma were determined by ELISA. Data are presented as means ± SEM and are representative of results from two separate experiments.