Fig. 3.

Effects of alemtuzumab on growth and survival of neoplastic cells

A: NALM-1 cells (CD52⁺), BL-41 cells (CD52⁺), RAJI cells (CD52⁺) and REH cells (CD52⁺) and B: BV-173 cells (CD52⁻) TOM-1 cells (CD52⁻), Z-119 cells (CD52⁻) and RAMOS cells (CD52⁻) were incubated in various concentration of alemtuzumab (10–300 μg/mL) in RPMI-1640 medium with either 30% serum (black bars), or 30% heat-inactivated serum (open bars) at 37 °C for 1 hour. Thereafter, cells were stained with propidium iodide (PI) and analyzed for cell viability on a FACSCalibur. Results represent the mean ± SD from 3 independent experiments. Asterisk (*): P < .05. C: Primary cells from patients with ALL with CD52⁺ LSCs (#18, #19 and #20; upper panel) or patients with ALL with CD52⁻ LSCs (#44, #46 and #48; lower panel) were incubated in alemtuzumab (10–300 μg/mL) in the presence of 30% human serum at 37 °C (5% CO₂) for 1 hour. Then 10 μL calibration beads were added. Cells were washed and then stained with antibodies against CD34, CD45, and CD38 for 15 minutes. Cells were then subjected to DAPI staining to count viable cells on a FACSCanto II. The left panels (black bars) show the effects of alemtuzumab on CD34⁺/CD38⁻ cells and the right panels (open bars) show the effects of alemtuzumab on CD34⁺/CD38⁺ cells. Results represent the mean ± SD from 3 independent experiments. Asterisk (*): P < .05.