Effect of TRAIL on committed myelocytic–monocytic precursors.

At days 4 to 8, serum-free liquid cultures of CB CD34⁺hemopoietic progenitors supplemented with SCF + GM-CSF were left untreated or were incubated with TRAIL for 3 additional days. (A) Phenotypical characterization of untreated and TRAIL-treated cultures by staining with anti-CD14 and anti-CD11b mAbs. Shadowed histograms represent cells stained with mAbs specific for the indicated antigens, whereas unshadowed histograms represent control cells, stained with control mAbs. Percentages of positive cells are indicated in each panel. Data shown are from a single experiment representative of 6 independent experiments with similar results. (B) Morphologic features of untreated and TRAIL-treated cultures revealed by staining with May-Grünwald-Giemsa solution. Different cell types are indicated. Mo indicates monocyte; Ma, macrophage; Gp, granulocyte precursor; Mn, monoblast. Representative fields of 6 separate experiments are shown. Original magnification, × 400.