Flow cytometric analysis of TRAIL-induced apoptosis and cell-surface expression of DR4 and DR5 in primary Ph1-positive ALL cells.

(A) Leukemic blasts from patients 8 and 9 listed in Table 3 were cultured for 12 hours with or without rhsTRAIL (100 ng/mL) in the presence or absence of neutralizing anti-TRAIL mAb RIK-2 (10 μg/mL), and then stained with FITC-conjugated Annexin-V. The percentages of positive cells are indicated in each panel. (B) Cell-surface staining of Ph1-positive primary leukemia cells with anti-DR4 and DR5 mAbs. Leukemic blasts from Ph1-positive ALL cases (patients 1, 2, 8, and 9 listed in Table 3) and a CML-BC case (patient 12) were stained with control mouse IgG or antihuman DR4 and DR5 mAbs, and analyzed by flow cytometry. Shaded and unshaded peaks correspond to specific and control stainings, respectively. Relative fluorescence intensity (RFI) is indicated in each panel.