Rhesus DC subsets display functional characteristics of CD11c⁺ pre-DCs and CD123⁺⁺ pre-DCs. (A) Freshly sorted rhesus CD11c⁺ pre-DCs show significantly augmented secretion of IL-12 p40 after 24-hour stimulation with rhCD40L (3 μg/mL) in comparison with nonstimulated CD11c⁺ pre-DC cells. Data are mean ± SD and are representative of 2 independent experiments. (B) Production of IFN-α by flow-sorted rhesus CD123⁺⁺ pre-DCs but not CD11c⁺ pre-DCs after stimulation with HSV (Kos strain). Freshly isolated pre-DCs were stimulated with 10 pfu/cell for 24 hours in complete medium. In contrast to freshly sorted, noninfected CD123⁺⁺ pre-DCs or to HSV-stimulated CD11c⁺ pre-DCs exposed to an equivalent viral concentration, only the HSV-activated CD123⁺⁺ pre-DCs secreted detectable IFN-α (see also Figure 8B inset, which demonstrates IFN-α production by intracellular cytokine staining under the same conditions). Data are representative of 3 separate experiments; error bars represent SD.