FIG 5.

CD4⁺ T cells mediate the early mortality of infected mice in the absence of IL-10 function. (A) Groups of 5 CD4^−/− (triangles) 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 (filled symbols) on days 3 and 5 after infection, respectively. Mice were monitored for parasitemia and survival. (B) Groups of 5 CD4^−/− (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 day 3 or 5 postinfection, 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.