Figure 7. WT, Irf3^−/−×Irf7^−/− DKO, and Irf3^−/−×Irf5^−/−×Irf7^−/− TKO immortalized MEFs were transfected with plasmids expressing myc-tagged IRF-5 or residues 1–229 of RIG-I (N-RIG) and analyzed at 24 hours after transfection by western blot (A) or qRT-PCR (B–D).

A. Transfected cell lysates were separated by SDS-PAGE and N-RIG or IRF-5 were detected with an anti-myc-tag antibody. Un: no transfection. Expression of N-RIG and IRF-5 was decreased slightly upon co-transfection, likely secondary to promoter competition. B–D. Expression of the indicated ISGs was measured from total RNA by qRT-PCR. Gene expression was normalized to Gapdh and is displayed as the fold increase compared to untransfected cells on a log₂ scale. Data represent the average of four samples from two independent experiments and are expressed as the mean ± SEM. The co-transfection group was compared to transfection with the individual plasmids by two-way ANOVA for DKO and TKO groups; asterisks indicate differences that are statistically significant (****, P<0.0001; ***, P<0.001; **, P<0.01; *, P<0.05).