STAT1 phosphorylation and expression of IFN-inducible genes after TLR7 triggering depends on the PI3K-p38MAPK pathway. GEN2.2 cells were untreated or stimulated with Flu, CL097, or IFN-α for 30 minutes or 3 hours. (A) Phospho-p38MAPK (pT180/pY182) was quantified on whole-cell lysates by CBA. Data shown are representative of 2 independent experiments. (B) GEN2.2 cells were untreated or stimulated with Flu, CL097, or IFN-α for 30 minutes in the absence or presence of the PI3K inhibitor LY. Cells were fixed and permeabilized for phospho-p38MAPK (pT180/pY182) analysis by flow cytometry. The mean percentages and SDs from duplicate values of 2 independent experiments are shown. (C) Phospho-STAT1 (pY701) and (D) TRAIL expression were analyzed by flow cytometry after 2 hours or 4 hours of stimulation of GEN2.2 cells with Flu, CL097, or IFN-α in the absence or presence of LY and the specific p38MAPK inhibitor SB203580 (SB). The mean percentages and SDs from duplicate values of 3 independent experiments are shown. Blood-isolated pDCs were unstimulated or stimulated with Flu or CL097 for 4 hours in the absence or presence of LY and SB. (E) Expression of TRAIL was evaluated by flow cytometry. Dot plots representative of 2 experiments are shown. The percentage of TRAIL-positive cells is indicated on each plot. (F) CXCL10 production was measured in cell culture supernatants by CBA. The mean and SD from duplicate values of 2 experiments performed with 2 different donors are shown.