Purpose: To investigate the immunomodulatory effects of human corneal stromal cells on the function of Th17 cells, in vitro.
Methods: Th17 cells were co-cultured with corneal stromal cells with or without 1-methyltryptophan, 1400w dihydrochloride, interleukin (IL)-10 inhibitor, or transforming growth factor-beta (TGF-β) inhibitor. The secretion of IL-17A by Th17 cells and the upregulation of T regulatory (Treg) cell frequencies were evaluated. Transwell assays were conducted to evaluate whether the immunomodulatory effects of stromal cells were dependent on cell-to-cell contact.
Results: Corneal stromal cells suppressed the secretive function of Th17 cells and upregulated Treg cell frequencies, enhancing TGF-β. Tranwell assays showed similar immunomodulatory effects of the stromal cells on the function of Th17 cells. TGF-β inhibitors attenuated the suppressive effects of the stromal cells on the function of Th17 cells, whereas other inhibitors didn't.
Conclusion: It which indicates that human corneal stromal cells suppress the function of Th17 cells through a TGF-β-dependent pathway.
Keywords: Cornea; IL-17; T cells; T regulatory cells; TGF-β; Th17 cells; stromal cells.