Down-regulation of ERK1/2 and p38 activation in ILC3s by lethal toxin.

<p>MNK-3 cells were pretreated with lethal toxin (1 μg/ml) for 2 hr followed by IL-23 stimulation as indicated. Cell lysates were harvested and subjected to immunoblot analysis for MEK1, MEK2, MKK3, MKK6, phosphorylated ERK1/2 (p-ERK1/2), total ERK1/2 (t-ERK1/2), phosphorylated p38 (p-p38), total p38 (t-p38) and actin. Shown is a representative blot for n = 2–4 experiments. <b>(B)</b> MNK-3 cells were pretreated with anti-IL-23 p19 antibody (5 or 50 μg/ml) for 1 hr followed by IL-23 stimulation for 15 or 30 min. Cell lysates were subjected to immunoblot analysis for phosphorylated ERK1/2 (p-ERK1/2), total ERK1/2, phosphorylated p38 (p-p38), total p38 and actin. Shown is a representative blot for 2–4 experiments. (<b>C</b>) <i>In vitro</i> expanded human Lin^- CD127⁺ cells or (<b>D</b>) mouse Lin^- CD127⁺ c-Kit⁺ Thy1.2⁺ cells expanded from splenocytes of <i>Rag1</i>^<i>-/-</i> mice were treated with lethal toxin for 2 hr followed by IL-23 stimulation for 30 mins. Cell lysates were analyzed for MEK1, phosphorylated ERK1/2 (p-ERK1/2), total ERK1/2 and actin by immunoblot analysis. Shown are representative blots from 2 independent experiments for both C and D.