Fig. 3.

Overexpression of GBP1 or GBP2 can rescue pyroptosis and bacterial restriction in GBP1^KO cells. A549 cells were stably transduced to express mCherry or mCherry-GBPs. Cells were then infected with bioluminescent S. flexneri and cell death was measured over time using sytox green fluorescence in cells primed with 100 U/mL IFNγ overnight before infection (A). The sytox green signal at 4 h was used to determine statistical significance (B). Bacterial luminescence was measured over time (C). Luminescence measurements from the 6 h timepoint were used to calculate the growth of each strain in primed cells relative to unprimed cells (D). Data are averages from three independent experiments and are represented by mean ± SD. Two-way ANOVA with Tukey’s multiple comparisons test was used. Statistical comparisons are shown by letters, with bars sharing no matching letters being significantly different. Purple letters correspond to statistical comparisons for wild-type S. flexneri, and orange letters correspond to S. flexneri ΔipaH9.8ΔospC3.