Figure 3.

at-RA inhibits TGF-β–mediated induction of IL-10 in CD4 T cells. (A) Analysis of gut-homing receptor expression on CD4 T cells activated on CpG-BMDC in the presence of TGF-β. Shaded histograms, isotype control; open histograms, antibody to indicated marker. (B) Naive CD4 T cells were stimulated with CpG-BMDC and TGF-β only or TGF-β plus 100 nM at-RA for 3 d before being analyzed for expression of GFP and Thy1.1. (C) Naive CD4 T cells were stimulated on unactivated or preactivated BMDC alone or in the presence of TGF-β only, TGF-β plus 100 nM at-RA, or TGF-β plus 1 µM LE540. On day 5, cells were restimulated for 5 h with D10 BMDC and 1 µg/ml OVA peptide in the presence of brefeldin A and analyzed for expression of Thy1.1, GFP, and IL-17A. All FACS plots are gated on CD4 T cells and numbers represent the percentages of cells in the respective quadrants. (D) The polarized T cell populations were restimulated on day 5 with anti-CD3 and anti-CD28 antibodies for 24 h before the IL-10 content of culture supernatants was determined by cytometric bead array. Mean cytokine concentrations ± SEM are shown. *, P < 0.05. All data are representative of at least three experiments.