Figure 3.

IDO1 expression induced T_regs. Expression of Foxp3 on (a) allogeneic and (b) autologous CD4⁺CD25⁺ T after 5-day culture with or without high IDO-expressing DCs that is matured with IL-1β/IL-6/TNF-α/PGE₂ (complete cocktail), in presence or in absence of the IDO1-specific inhibitor 1-MT-L. The results showed in (a)-(b) are expressed as the mean ± SEM of 5 different experiments. ^** P < 0.01. (c) CD3⁺ T cells were stimulated by allogeneic immature DCs in the presence and absence of CD4⁺CD25⁺ T cells. CD4⁺CD25⁺ T cells were purified after 5 days of culture in presence of high IDO-expressing DCs (i.e., matured with PGE₂). The results are expressed as percentage of CD3⁺ T cell proliferation with the proliferation observed in absence of CD4⁺CD25⁺ T cells (w/o T_regs) as 100%. The results are expressed as the mean ± SEM of 3 different experiments. ^** P < 0.01 versus w/o T_regs.