Phenotypic dissection of peripheral-blood DCs. (A) Sequential analysis to identify blood DC populations as indicated by the arrows. Live PBMCs were gated on lineage negative/HLA-DR⁺ cells and divided into BDCA-2 positive (pDCs) and negative populations. BDCA-2 negative were further divided into 4 subsets characterized by CD34, BDCA-3, CD1c, and CD16 surface expression. SSC and FSC highlight the typical lymphomonocytic morphology of these cells. (B) Each of the 4 surface antigens identifies a single, nonoverlapping population of cells as exemplified by the dot plots of CD16 versus CD34, CD1c, and BDCA-3 reported here. (C) Histogram of the lineage-negative/HLA-DR⁺ cell population stained with a mixture of antibodies against the indicated cell subset markers. (D) All CD34⁺ cells are lineage-negative/HLA-DR⁺ as shown in these fluorescent dot plots. Data reported in A, B, C, and D are representative of one donor out of 10. (E) The same sequential analysis of bone marrow cells as shown in A and B for PBMCs. Representative data from one donor out of 10.