FIG 2.

Toxoplasma can inhibit IFN-γ-responsive gene expression in the presence of both cycloheximide and MG132. (A and B) HFFs were pretreated with 50 μg of CHX/ml for 40 min, infected with an RH strain for 1 h, and stimulated with 100 U of IFN-γ/ml for 1 h. CHX was left on the treated cells for the entire experiment. Cells were also left untreated (UT) and/or uninfected (UI). Induction of IRF1 mRNA was determined by RT-qPCR analysis and normalized to ACTB transcript levels. (A) The averages of two experiments are shown; error bars represent the SEM. (B) The fold inhibition by RH infection in each of the conditions was calculated for each experiment, and averages of two experiments are shown. Error bars represent the SEM. (C) HEK293 GAS or STAT1 reporter cell lines were pretreated with MG132 or left untreated for 40 min. Cells were then infected with RH parasites for 3 to 5 h, subsequently stimulated with 100 U of IFN-γ/ml for 15 h, and lysed, and the luciferase activity was measured. MG132 was left on the treated cells for the entire experiment. The data were normalized within each experiment to the uninfected, unstimulated (US) sample, and the data shown are the average fold induction and the SEM from three independent experiments. Asterisks (*) indicate P < 0.05.