pDCs from DKO-hu mice are functional. (A) pDCs (CD45⁺CD3⁻CD4⁺CD123⁺) were purified as described in “pDC purification,” and the purity was monitored by CD4 and CD123 staining (> 95% pure). (B) Purified pDCs (10 000) were cultured in the presence of influenza virus or HSV for 16 ours. Supernatants were collected and IFNα, IL-6, MIP1β, and IP10 were measured with the Human Cytokine Luminex kit. Error bars are SDs from triplicate samples. (C) Purified pDCs were stimulated with influenza virus or HSV for 48 hours, and then stained with anti–human CD80, CD83, CD86, and HLA-DR monoclonal antibodies. The number in each plot is the mean fluorescence intensity of total pDCs after culture. Flu indicates influenza virus.