Monocyte-derived dendritic cells (DC) express CD95 but resist CD95-mediated apoptosis.

(A) Flow cytometry analysis of CD95 membrane expression on DC generated from plastic-adherent peripheral blood mononuclear cells cultured for 6 days in granulocyte-macrophage colony-stimulating factor and interleukin 4. (B) DC were incubated in medium alone (open columns) or in the presence of agonistic anti-CD95 monoclonal antibody (mAb; 1 μg/mL) (solid columns) with or without cycloheximide (CHX; 10 μg/mL). After 18 hours, the percentages of apoptotic or nonviable cells were assessed with use of flow cytometry after staining with fluorescein isothiocyanate–conjugated annexin V and propidium iodide (PI). Data are shown as the mean (± SEM) of the sums of annexin V–single-positive cells, annexin V– and PI–double-positive cells, and PI–single-positive cells in 9 experiments on samples from 9 different donors. * P = .0005 compared with DC incubated with CHX in medium alone (Wilcoxon 2-tailed test).