IL-3 induces CCR6 and CCR10 expression on purified blood pDCs as well as their migration in response to CCL20, CCL27, and CCL28 in vitro. (A) CCR6 and (B) CCR10 were measured on freshly isolated blood pDCs and cultured in the presence of IFN-α or IL-3 during 72 hours. Shading represents isotype control. Dose-response to (A) CCL20 and (B) CCL27 or CCL28 of freshly isolated and 72-hour IL-3–cultured blood pDCs in transwell assay. Results are expressed as number of migrating cells (mean of duplicate experimental points). (C) Percentages (left panel) and mean fluorescence intensity (right panel) of freshly isolated and IL-3–treated blood pDCs expressing CCR6 and CCR10 at various time points after culture. Data are representative of 3 independent experiments. In the experiment shown, pDC viability in IL-3 was 60%, 60%, 68%, and 57% at 16, 24, 48, and 96 hours, respectively.