(A) Splenic CD4+ T cells were stimulated with plate-bound anti-CD3 and anti-CD28 mAbs under Treg polarizing conditions for 4 d in the presence of 1.5 μM Gal-8. TDG and α2,3-sialyllactose were used as galectin inhibitors. (B) CD4+ T cells were isolated from OT-II mice and cultured under Treg polarizing conditions with irradiated congenic splenocytes in the presence of OVA323–339 and Gal-8, as indicated. Relative represents percentage of marker positive cells in gated population as compared to control, and % of max represents the total number of cells at a given fluorescence intensity compared to the maximum number of cells at any intensity for a given sample. Error bars represent mean ± SEM of three independent experiments. P values were determined by ANOVA with Tukey’s multiple comparison test. *, p < 0.05;**, p < 0.01. Significance in panel A is compared to Treg cell polarization in the presence of Gal-8.