FIG 1 .

IFN-γ priming promotes ubiquitin deposition on inclusions in human cells. (A) A549 epithelial cells were infected with either C. muridarum (C.m.) or C. trachomatis (C.t.) and primed with IFN-γ (+IFNγ) (100 U/ml) at 3 hpi or left unprimed (−IFNγ). At 20 hpi, cells were stained for ubiquitin (Ub) with antibody FK2 (red), rabbit anti-Slc1 (green), and DNA (blue). Representative images of Ub-positive inclusions are shown. Bars = 10 μm. (B) Colocalization of ubiquitin (FK2) with inclusions (incl) in A549 cells and HeLa cells was quantified as described in Materials and Methods. At least 100 inclusions were counted for each condition. Data are representative of three independent experiments. Values are means ± standard deviations (SD) (error bars). Values that are statistically significantly different by two-tailed unpaired Student’s t test are indicated by a bar and asterisks as follows: *, P < 0.05; ***, P < 0.005; ****, P < 0.001.