CCR7 expression and responsiveness to CCL19 are acquired before CCR6 expression and responsiveness to CCL20 on cultured blood pDCs. (A) Representative staining (left) and the percentages of CCR7⁺ cells (right) among CD123⁺ BDCA2⁺ pDCs in blood and tonsil are shown. Each point represents an independent donor (n = 8-10); and horizontal bars, means. The P value was obtained by a nonparametric Wilcoxon test. (B) CCR7 and CCR6 expression and (C) migratory capacities to CCL19 and CCL20 (1 μg/mL) were measured on freshly isolated, IL-3, and IL-3 + CpG-B-treated blood pDCs at various times after culture by flow cytometry and transwell assay, respectively. Percentages of positive cells are indicated in each dot plot (data are representative of 3 independent experiments), and pDC migration is shown as migration index (mean ± SD for 6 independent experiments).