Flow cytometry analysis of pDCs in whole blood. (A) Blood DCs were gated from whole-blood cells by assembling R1 and R2 regions. Plasmacytoid DCs were identified as CD11c^-/HLA-DR⁺ and CD123high. (B) Cord blood and adult blood samples (1 mL) were incubated overnight with or without 50 μg CpG 2006 and analyzed by flow cytometry for surface expression of the indicated molecules on pDCs identified as Lin^-/CD11c^-/HLA-DR⁺ cells. Histograms represent the mean ± SEM of median fluorescence intensities in 10 independent experiments on different donors. ^**P < .01; ^***P < .001.