Figure 3.

IL-12 treatment rescues PD-1^−/− mice during T. gondii infection. WT and PD-1^−/− mice were treated with 200 ng of recombinant IL-12 (rIL-12) 48 and 24 h prior to T. gondii infection. (A) WT and PD-1^−/− were infected with 50 cysts and monitored daily for survival. (B) Cyst counts from T. gondii-infected mice treated or untreated with IL-12 are shown. (C) Serum levels of IFN-γ were determined in samples harvested 7 days after infection. (D) Total DNA was extracted and PCR performed for T. gondii B1 gene at day 15 after infection. Data are shown as mean + SEM of n = 8 mice/group and are from a single experiment representative of three independent experiments. ***p < 0.001, one–way ANOVA.