mDC2 secrete high amounts of IFN-λ. (A) IFN-λ production by peripheral blood DC subsets after a 24-hour culture in medium alone (−) or in the presence of the indicated stimuli. (B) IFN-λ production by mDC1 (left column) and mDC2 (right column) in response to polyI:C, R848, and IFN-γ. (C) IFN-λ production by DC subsets in tonsils. Values represent the mean of 16 PBMC donors in 8 different experiments and 7 TMC donors in 5 experiments. *P < .05.