Lack of toxicity of TRAIL on unilineage committed myelomonocytic precursors at intermediate stages of differentiation.

Ten-day unilineage granulocytic (SCF + IL-3 + G-CSF) and monocytic (SCF + IL-3 + M-CSF) cultures were incubated with irrelevant IgM mAb and rHis6-tag peptide (CONT), TRAIL, or anti-CD95 (CH 11) IgM mAb for 20 hours. Apoptotic granulocytic cells were detected by staining with propidium iodide combined to CD15, whereas apoptotic monocytic cells were detected by annexin V staining combined to CD14. Percentages of cells in the respective quadrants are indicated. Quadrants were set based on negative controls treated with isotype-matched irrelevant mAbs (not shown).