Poly I:C treatment does not induce phosphorylation of p38, JNK, and ERK in human dendritic cells but does so in RA synovial fibroblasts. (A) Human DCs and (B) synovial fibroblasts from RA tissue were either left untreated (Un) or stimulated with LPS (100 ng/mL) or poly I:C (20μg/mL). The cell lysates were examined for phospho-p38, phospho-JNK, phospho-ERK, or β-actin by Western blotting. Representatives of 3 independent experiments are shown.