FIG. 3.

Inhibition of T. gondii growth by treatment of macrophages with TgCyp18. (A) Posttreatment experiment. Peritoneal macrophages (1 × 10⁶ macrophages) from B6 mice and CCR5^−/− mice were infected with T. gondii (2 × 10⁵ parasites) for 12 h, and the culture was then incubated with TgCyp18, MTgCyp18, 50 μg/ml GST, or 10 ng/ml LPS. After 24 h, [³H]uracil uptake in tachyzoites was measured. (B) Pretreatment experiment. Peritoneal macrophages (1 × 10⁶ macrophages) from B6 mice and CCR5^−/− mice were incubated with TgCyp18, MTgCyp18, 50 μg/ml GST, and 10 ng/ml LPS for 12 h before the cells were infected with T. gondii (2 × 10⁵ parasites). After incubation for 24 h, the [³H]uracil uptake in tachyzoites was measured. The percentage of growth was calculated by dividing each value (control or tested) by the average means of the control samples (parasite growth in nontreated macrophages) multiplied by 100. Each value represents the mean ± the standard deviation of data from triplicate samples. Statistical significance was calculated between the TgCyp18- or MTgCyp18-pretreated B6 wild-type macrophages and the pretreated CCR5^−/− macrophages or the negative control groups. Moreover, significant differences were calculated between the positive controls for both macrophages and the negative control using ANOVA and a follow-up test (LSD). *, P < 0.001.