Figure 4. IL-17 upregulates pIgR in epithelial cells through activation of PI3K and NF-κB pathway.
(A) HT-29 cells were treated with human TNF (10ng/ml), IL-17A (20ng/ml), or TNF and IL-17A for the hours indicated. PIGR mRNA expression was analyzed by RT-PCR, and normalized to GAPDH mRNA. Significant differences are compared to non-treated controls. *p<0.05 compared to non-treated cells. Data reflects three independent experiments. (B) HT-29 cells were treated with TNF, IL-17A, or TNF and IL-17A for 48 hours. PIgR expression was detected by Western blot, with Actin as a loading control. One of two experiments with similar results was shown. (C, D) HT-29 cells were treated with TNF, IL-17A, or TNF and IL-17A for the time indicated. Phosphorylated NF-κB p65 was detected by western blot (C), with total NF-κB p65 as a loading control. (D) Relative increase of phosphorylated p65 over non-treated cells, as a percentage of total NF-κB p65. One of two experiments with similar results was shown. *p<0.05 of IL-17 treated cells compared to non-treated cells. (E) HT-29 cells were treated with PI3K inhibitor LY249002 (10uM) or NF-κB inhibitor Bay11-7082 (10uM) for one hour, then treated with TNF, IL-17A, or TNF and IL-17A for four hours. PIGR mRNA expression was analyzed by RT-PCR, and normalized to GAPDH mRNA. Significant differences are compared to nontreated controls. *p<0.05 compared to non-treated cells. Data reflects five independent experiments.