Mature CD34⁺ HPC-derived LCs express the highest levels of IL-15R-α among all conventional DC subtypes. (A) Highly purified populations of cytokine-generated, immature and mature moDCs, CD34⁺ HPC-derived LCs, and CD34⁺ HPC-derived DDC-IDCs underwent quantification of IL-15R-α mRNA by real-time RT-PCR. Values were normalized to the housekeeping gene 18S rRNA subunit. Data represent the averages of quadruplicate means ± SEM from 3 independent experiments. *P = .019, immature LCs vs immature moDCs. **P = .0005, immature LCs vs immature DDC-IDCs. ***P = .01, mature LCs vs all other DC subtypes. (B) Cytocentrifuged, fixed, and permeabilized mature moDCs and LCs were stained with polyclonal anti–IL-15R-α followed by rhodamine Red-X–conjugated donkey anti–goat IgG (red). F-actin control was stained by bodipy-conjugated phallacidin (green), and nuclear DNA was stained with 4,6-diamidino-2-phenylindole (DAPI; blue). Cells were examined by immunofluorescent microscopy. Scale bars represent 10 μm. (C) At least 20 cells in randomly selected fields from each experiment were evaluated to calculate the average voxels, which represent digitalized 3-dimensional image data. Shown in the bar graph are the averaged replicate means from 3 independent experiments ± SEM. *P = .0014 for IL-15R-α. P = not significant for F-actin.