Irgm1 and Irgm3 are critical co-factors for the targeting of GBP proteins to <i>C.</i> <i>trachomatis</i> inclusions and <i>T. gondii</i> PVs.

<p>(<b>A</b>) Localization of ectopically expressed GFP-Gbp2 was monitored in <i>C. trachomatis</i> infected MEFs at 20 hpi. Arrows point at Hoechst-stained inclusions (<b>B</b>). Wildtype and <i>Irgm1/m3^−/−</i> MEFs were infected with <i>C. trachomatis</i>, left untreated or treated with IFNγ at 3 hpi. Cells were fixed at 20 hpi and stained with anti-<i>C. trachomatis</i>, anti-Gbp2 and Hoechst. (<b>C</b>) Co-localization of Gbp2 with inclusions in wildtype and <i>Irgm1/m3^−/−</i> MEFs was quantified as described in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003414#s4" target="_blank">Materials and Methods</a>. Error bars represent standard deviations of three independent experiments. Statistical significance of group values relative to wildtype and between marked groups is shown (*, p<0.05; **, p<0.01; and ***, p<0.005). (<b>D</b>) MEFs were transfected with FLAG-Gbp1, infected with <i>C. trachomatis</i> and activated with IFNγ at 3 hpi. Cells were fixed at 20 hpi and stained with anti-FLAG and anti-<i>C. trachomatis</i>. Representative images are shown. (<b>E</b>) MEFs were treated overnight with 200 U/ml of IFNγ prior to infections. Localization of endogenous Irgb10 to <i>T. gondii</i> PVs was monitored at 0.5 hpi. Data are representative of three independent experiments (*, p<0.05 relative to wildtype). (<b>F</b>) Localization of endogenous Gbp2 to <i>T. gondii</i> was monitored at 0.5 hpi. Data are representative of three independent experiments (*, p<0.05 relative to wildtype). Representative epifluorescent images of <i>T. gondii</i>-infected wildtype and <i>Irgm1/m3^−/−</i> MEFs are shown.