Fig. 2.

Effect of TBK1 and IKKε deficiency on IRF expression and activation. (A) WT and IKKε^−/− FLS transfected with TBK1 siRNA were stimulated with 20 µg/ml poly(I:C) for 24 h and total RNA was isolated. IRF3 and IRF7 gene expression was determined by qPCR and normalized to HPRT. IRF7 expression was significantly decreased in TBK1-deficient FLS, regardless of IKKε deficiency (*P < 0.04, n = 3 lines/group). IRF3 expression was not altered by the lack of TBK1 or IKKε. (B) TBK1-deficient WT and IKKε^−/− FLS were treated for 2 h with poly(I:C) (20 µg/ml) and nuclear extracts were prepared. Native PAGE and western blot analysis were performed using anti-IRF3 antibody. IRF3 monomeric and dimeric forms (←). IRF3 dimerization was inhibited in TBK1-deficient WT and IKKε^−/− cells, indicating that both kinases regulate IRF3 activation in FLS. The figure is representative of three separate experiments.