TRIP inhibits IRF3 activation. (A) Mouse peritoneal macrophages were transfected with IRF3 reporter plasmid together with TRIP expression plasmid or control plasmid, and luciferase activity was analyzed after treatment with LPS or poly(I:C) for 6 h. (B) HEK293 cells were transfected with IRF3 reporter plasmid together with control plasmid (Ctrl), TRIP WT plasmid, or TRIP point mutant plasmid (CA), and luciferase activity was analyzed after transfection with poly(I:C) for 6 h. (C) HEK293 cells were transfected with RIG-I, MAVS, and TBK1, along with IRF3 reporter plasmid and TRIP plasmid, and luciferase activity was analyzed. (D) Western blot analysis of phosphorylated IRF3 and total IRF3 in HEK293 cells transfected with TRIP expression plasmid or control empty vector followed by transfected with poly(I:C). (E) Western blot analysis of phosphorylated IRF3 and total IRF3 in mouse peritoneal macrophages transfected with control siRNA (Ctrl) or TRIP siRNA (siRNA) and stimulated with poly(I:C). **, P < 0.01. Data are representative of three experiments (mean and SD of six samples in A, B, and C). Similar results were obtained in at least three independent experiments in D and E.