IL-6 and IL-12, but not IFN-α, production by pDCs is regulated by NF-κB1 and c-Rel. Wild-type, C-Rel^–/–, Nfkb1^–/–, and Nfkb1^–/–C-Rel^–/– splenic cDCs and pDCs were stimulated in culture for approximately 18 hours in a cytokine cocktail in the absence (–, closed bars) or presence (+, open bars) of CpG1668-ODN. Culture supernatants were harvested and examined for cytokine expression by ELISA. Data are representative of 3 independent experiments. Error bars represent the variation among replicate samples within an experiment. (A) IFN-α production by pDCs. (B) IL-6 production by wt and Nfkb1^–/–C-Rel^–/– cDCs. (C) IL-12p70, RANTES, and IL-6 production by pDCs.