Flow-sorted rhesus CD11c⁺ pre-DCs stimulate allogeneic T cells. Five-day MLR cultures were performed with freshly sorted rhesus CD11c⁺ pre-DC or CD123⁺⁺ pre-DC subsets or with CD11c⁺ pre-DCs matured after rhCD40L stimulation. Flow-sorted DC subsets were γ-irradiated before culture with bulk allogeneic rhesus PBMCs at various stimulator-responder ratios (x-axis). T-cell proliferation was measured by thymidine incorporation (y-axis). Data are mean ± SD and are representative of 3 separate experiments. Freshly isolated CD11c⁺ pre-DCs were modestly immunostimulatory in comparison with CD123⁺⁺ pre-DCs that failed to induce proliferation.