MDCs acquire resistance to UVB irradiation.

(A) Surface phenotype of IDCs and MDCs used in this study. Cells were studied for the expression of the indicated surface markers and analyzed by FACS. Relative fluorescence intensity, x-axis; relative cell number, y-axis. Dotted lines, IDCs; solid lines, MDCs. Control mAb staining histograms were confined within the first decade on the x-axis (not shown). (B) IDCs and MDCs from the same donor were exposed to UVB (1 J/cm²), and the percentage of hypodiploid nuclei was evaluated by propidium iodide staining and FACS analysis at the indicated time points. ○ and ▵, untreated cells; ▪ and ▴, UVB-treated cells; ▴ and ▵, MDCs; ● and ○, IDCs. Means ± SD from 5 experiments are shown.