Fig. 6.
Flagellin and IL-1β stimulate phosphorylation of p38. Calu-3 cells were grown to confluence, rinsed, and S. typhimurium flagellin (10−7 g/ml) or IL-1β (10 ng/ml) was added. Flagellin- (A) and IL-1β-treated (B) cells were analyzed for phosphorylation of p38 (p-p38) after times of treatment shown using specific antibodies. Typical Western blots of p-p38 and total p38 (of 3–5 similar experiments each) are shown. -Fold activation refers to increase above control level as determined from densitometric analysis of the Western blots. On average, flagellin caused a 2.3 ± 0.3-fold (n = 4) increase in phosphorylation after 20 min and a 2.5 ± 0.8-fold (n = 5) increase in phosphorylation after 30 min. IL-1β caused an 8.5 ± 3.7-fold (n = 3) increase in phosphorylation after 30 min.