PDCs and CD11c⁺ DCs induce different cytokine profiles in CD4⁺ T cells as early as 12 hours after SEB stimulation. Cocultures of CFSE-labeled CD4⁺ T cells and PDCs or CD11c⁺ DCs were stimulated with SEB. (A) At 12, 24, and 48 hours the secretion of IL-10 and IFN-γ was measured in CD3⁺CD123⁻ (PDC cultures) or CD3⁺CD11c⁻ (CD11c⁺ DC cultures) cells with the cytokine secretion assay. One experiment representative of 3 is shown. (B) IL-10 and IFN-γ were measured with CBA in supernatants harvested at 48 hours from the cocultures described in panel A. Levels of IL-10 were 14.2 ± 6.7-fold higher in cultures with PDCs than with CD11c⁺ DCs (n = 7, *P = .001), whereas the amounts of IFN-γ were 2.0 ± 0.2-fold higher in the cultures containing CD11c⁺ DCs as opposed to PDCs (n = 7, *P = .007). Means and SEM are indicated in panel B.