Figure 4.

IDO1 expression inhibited leukemia-specific IFN-γ production. AML cells were lysed and used for the pulsing of immature Mo-DCs. Mo-DCs were subsequently matured with the cytokine cocktail containing PGE₂. Autologous CD3⁺ T cells were cocultured with the preloaded and matured DCs for an overnight, in the presence or absence of the IDO1-specific inhibitor 1-MT-L. As control samples, unloaded Mo-DCs were used (data not shown). (a) CD3⁺ T cells, (b) CD4⁺ T cells, and (c) CD8⁺ T cells were tested for leukemia-specific intracellular IFN-γ production. Results are expressed as the mean ± SEM of 3 independent experiments. ^* P < 0.05, ^** P < 0.01 versus w/o DCs or versus medium alone.