Induction of STAT1-regulated genes in <i>T. cruzi</i>-infected cells.

<p>(A) HFF cells were either left untreated, stimulated for 6 h with 5 ng/ml of IFNγ or infected for 18 h with <i>T. cruzi</i> parasites at an MOI of 10 in the absence of cytokine exposure, as determined by real-time PCR assays. Histograms depict expression levels of the <i>mig1</i>, <i>gbp1</i>, <i>irf1</i>, <i>ido</i>, <i>stat1</i>, <i>inos</i>, and <i>nf-kb</i> gene before (white columns) and after 6 h stimulation of cells with IFNγ (grey columns) as well as after parasite infection (black columns). Specific gene induction was normalized to the expression level of the housekeeping gene <i>gapdh</i>. The data are presented as means and standard deviations from at least three independent experiments. (B) U3A cells lacking STAT1 expression showed no induction of these genes under the same experimental conditions as used in (A) (n.d. = not detectable). (C) Infectious dose-dependent increase in STAT1-regulated gene expression in <i>T. cruzi</i>-infected HFF cells. The <i>adam19</i> gene was used as a negative control (n = 3).