Poly I:C stimulation induces degradation of IκBα in fibroblasts but not in dendritic cells. (A) DCs and (B) RA-SFs were either left untreated (Un) or stimulated with poly I:C (20μg/mL) or LPS (100 ng/mL). The cell lysates were examined for the level of IκBα, β-actin, or α-tubulin by Western blotting. Representatives of 3 independent experiments per cell type are shown.