Effect of TRAIL on normal PBMCs or BMMCs.

PBMCs and BMMCs of healthy donors were treated with TRAIL (at concentrations up to 1000 ng/mL) for 24 hours. A dose-response analysis (by PI staining) of the normal B cells (A) indicates no shift of cells in the sub-G₁ region, consistent with lack of TRAIL-induced cell death at concentrations up to 1000 ng/mL. Panels B and C demonstrate that healthy donor's BMMCs are resistant to even 1000 ng/mL TRAIL. Dual-color flow cytometry, for CD38⁺-FITC and Apo2.7-PE revealed that apoptotic cells (Apo2.7-PE⁺) are not detected in either the CD38⁺ or CD38⁻populations of BMMCs. (Quadrants were set based on negative controls stained with MsIgG1-FITC and MsIgG1-PE.)