IL-22 reduces TNFα/IL-13 induced production of CCL17 in murine Clara cells.

<p><i>Panel A:</i> C22 cells were stimulated with recombinant IL-22, for the indicated time points. Protein lysates were subjected to SDS page gel electrophoresis and Western blot analysis performed with a pSTAT-3 specific antibody. Detection of total STAT-3 as loading control. Data are representative of 2 independent experiments. <i>Panel B and C:</i> C22 cells were stimulated with recombinant IL-13, TNFα, or a combination of both, for 5 hours or left untreated (US). To assess the effect of IL-22 on TNFα and TNFα/IL-13 induced TARC expression, cells were preincubated with recombinant IL-22 for 4 hours and stimulated with the indicated cytokines for an additional 5 hours in the continued presence of IL-22 (IL-22 +). Controls were incubated with IL-22 only for a total of 9 hours. Relative TARC mRNA expression (panel B) was measured in triplicates by quantitative PCR and normalized to GAPDH expression levels. Results are shown as means±SEM of 5 replicates per treatment pooled from 4 independent experiments. TARC levels in cell culture supernatants (panel C) were assessed by ELISA after 48 hours. Results are shown as mean±SEM of triplicates and of 3 independent experiments. *p<0.01 vs. US, **p<0.001 vs. TNFα alone, ***p<0.05 vs. respective controls stimulated in the absence of IL-22.