MDSCs are suppressive of T-cell activation and proliferation. Healthy PBMCs and AML cells were cocultured for 5 days, and MDSCs were isolated by using flow cytometric sorting. T cells autologous to the MDSCs were isolated and stimulated with anti-CD3/CD28 ligation. MDSCs were added at a 2:1 ratio (Tc:MDSCs). (A) After 3 days of culture, T cells were analyzed for proliferation using CellTitreGlo cell luminescence assay (n = 3). After 3 days of culture cells were analyzed for (B) the expression of intracellular IFN-γ by flow cytometry as presented in a representative experiment (left) and summary of three independent experiments (right) and (C) markers of T-cell activation CD4⁺/CD25⁺/CD69⁺ (n = 3) and (D) the expression of intracellular IL-10 by flow cytometry, presented as a summary of three independent experiments. *P < .05. IgG, immunoglobin G.