CD40L/IFN-γ induced production of IL-12 by dendritic cells occurs independently of T cells.

A preparation of DCs was stained with fluorophor-conjugated monoclonal antibodies against CD11c and CD14; unsorted or CD11c⁺/CD14⁻ sorted cells were then plated in AIM V medium alone or with the combination of CD40L (1 μg/mL) and IFN-γ (1000 U/mL). After 24 hours, brefeldin A was added, and after 4 more hours cells were harvested, fixed, permeabilized, and stained with α-CD11c-FITC, α-CD83-PE, α-CD14-PerCP, and α-IL-12-APC. The fluorescence intensity of DCs stained with isotype control antibodies (used to construct regions) is shown in the upper panel. The number in the lower right corner of each panel indicates the percentage of IL-12⁺ DCs. (R3 is the region label generated during data analysis.) Data are representative of 2 experiments with similar results.