Fig. 3

Activated T cells promote MDSC apoptosis through the TRAIL–TRAILR pathway. a MDSCs were cocultured with T cells and mAbs against the indicated blocking antibodies and Annexin V expression on MDSCs was determined using FACS. b MDSCs were incubated for 48 h with rhTNF-α, rhINF-γ, rhTRAIL, or Fas agonist antibodies, and Annexin V expression on MDSCs was determined using FACS. c Apoptosis-related receptors were examined in MDSCs using qPCR. d Surface DR5 expression on MDSCs was measured using FACS. The data are representative of three subjects. e TRAIL⁺ T cells were determined 48 h following exposure to 15% ASN and CD3/28 antibodies (2 μg/mL). T cells in the control group were only treated with CD3/28 antibodies. f Type I interferons (10 ng/mL) and TNF-α (10 ng/mL) were added to the activated T-cell culture system and the expression of TRAIL was determined using FACS. g, h T cells were incubated for 48 h with CD3/28 antibodies (5 μg/mL) and mAbs against IFNAR1 (2 μg/mL) or the control Ab (IgG1, 10 μg/mL). The expression of TRAIL was analyzed using FACS (g); T cells were cocultured with MDSCs for 48 h and Annexin V expression was detected on MDSCs (h). i The expression of TRAIL (gray), CD3 (red), and IFNAR1 (green) in CRC tissues was determined using confocal microscopy. DAPI staining appears blue. Scale bar = 50 μm. Images in i are representative of five subjects. The data were generated from three (b–f) or four (a, g, h) independent experiments. The data are shown as the mean ± SEM. *p < 0.05; **p < 0.01; ***p < 0.001