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

(A) Localization of ectopically expressed GFP-Gbp2 was monitored in C. trachomatis infected MEFs at 20 hpi. Arrows point at Hoechst-stained inclusions (B). Wildtype and Irgm1/m3−/− MEFs were infected with C. trachomatis, left untreated or treated with IFNγ at 3 hpi. Cells were fixed at 20 hpi and stained with anti-C. trachomatis, anti-Gbp2 and Hoechst. (C) Co-localization of Gbp2 with inclusions in wildtype and Irgm1/m3−/− MEFs was quantified as described in Materials and Methods. Error bars represent standard deviations of three independent experiments. Statistical significance of group values relative to wildtype and between marked groups is shown (*, pD) MEFs were transfected with FLAG-Gbp1, infected with C. trachomatis and activated with IFNγ at 3 hpi. Cells were fixed at 20 hpi and stained with anti-FLAG and anti-C. trachomatis. Representative images are shown. (E) MEFs were treated overnight with 200 U/ml of IFNγ prior to infections. Localization of endogenous Irgb10 to T. gondii PVs was monitored at 0.5 hpi. Data are representative of three independent experiments (*, pF) Localization of endogenous Gbp2 to T. gondii was monitored at 0.5 hpi. Data are representative of three independent experiments (*, pT. gondii-infected wildtype and Irgm1/m3−/− MEFs are shown.