To investigate the immunomodulatory effects of human corneal stromal cells on the function of Th17 cells, in vitro.,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.,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.,It which indicates that human corneal stromal cells suppress the function of Th17 cells through a TGF-β-dependent pathway.