Figure 7. Absence of STING promotes Th17 polarization and IL-17A promotes fibrosis gene expression in vitro.

(A, B) Naive CD4⁺ T cells from spleen of WT and STING KO mice were differentiated into Th17 cells or Th1 cells. On day 3, the cells were collected and stimulated with PMA, ionomycin and Brefeldin A for 5 h. The frequencies of IL-17A⁺ (Th17) and IFNγ⁺ (Th1) cells were examined by flow cytometry. (C) 24h after the naive CD4⁺ T cells from spleen of WT mice were cultured for differentiation into Th17 cells, VE control or 50ug/ml DMXAA was added to the cell culture supernatant. On day 3, the cells were collected and stimulated with PMA, ionomycin, Brefeldin A for 5 h. The frequencies of IL-17A⁺ cells were examined by flow cytometry. Error bars show mean ± SD, n = 5 in each group. Data representative from three experiments are shown. (D) Primary mouse pancreatic stellate cells (mPSCs) isolated from WT CP mice were treated with mouse IL-17A (100 ng/mL) for indicated times and then lysed for western blot with p-ERK1/2, ERK1/2, IL-17RA, and αSMA. Data shown is from a representative of 3 independent experiments. Relative p-ERK1/2 expression (p-ERK1/2 / ERK1/2) is shown as bar graph (mean ± SD, one-way ANOVA). (E) mPSCs were treated with VE or mouse IL-17A (100 ng/mL) for 24 hours. mRNA expression of αSMA (αSMA), Fn1 (fibronectin), collagen1A1 and TGFβ (TGFb) were detected by qPCR. Bar graph represents mean ± SD (n=3 independent experiments). (F) Schematic presentation of Th17 and pancreatic stellate cell (PSC) interaction during CP.