Involvement of Indoleamine 2,3-Dioxygenase in Impairing Tumor-Infiltrating CD8+ T-Cell Functions in Esophageal Squamous Cell Carcinoma
Figure 6
Cytolytic activity of CD8+ T cells from both PBMCs and TILs was impaired by incubation with media created by IDO-positive Eca109 cells. Activated CD8+ T cells from both PBMCs (a) and TILs (b) were cultured with CM from Eca109 cells treated with or without 50-U/mL IFNγ and/or 100-M 1 MT for 24 hr, and cytolytic activity against Eca109 cells was evaluated using a standard LDH release assay. The E/T ratios are indicated. (c) Eca109 cells were treated with or without 50-U/mL IFNγ and/or 100-μM 1 MT for 24 hr. The Eca109 cell supernatants were analyzed for Kyn/Try production by HPLC. Columns, mean of three independent experiments. Bars, SD. *P < 0.05 compared with CD8+ T cells cultured in conditioned media derived from non-IFNγ-treated Eca109 cells.
