M-pDCs are activated and produce IFN-α in response to TLR9 stimulation and other cytokines in response to TLR7 stimulation. Highly purified, sorted M-pDCs or FL-pDCs were incubated for 18 hours with the TLR ligands shown. The surface phenotype of the pDCs were analyzed (A,B); gray histograms indicate surface expression levels of cells cultured in media only, and black histograms indicate the expression levels of cells cultured in the stimuli indicated. Supernatants were assayed by ELISA for the presence of IFN-α (C) or by cytometric bead assay (CBA) for the production of IL-6 and TNF-α (D). No IFN-γ, IL-10, IL-12p70, or MCP-1 was detected by CBA in the M-pDCs supernatants. The data shown are from one experiment representative of 3 experiments (A,B), 5 experiments (C), and 3 experiments (D). Error bars represent the range of duplicate samples.