IL-7 inhibits drug-induced apoptosis in primary T-ALL cells.

Leukemic cells were treated with doxorubicin (1 μM) or dexamethasone (2 μM) in the presence or absence of IL-7 (25 ng/mL) for 24 hours. Dot plots (A) are examples of inhibition of spontaneous (in medium) and drug-induced apoptosis by IL-7. Percentages of viable cells (PI⁻ and annexin V⁻ cells) are indicated. At day 0, percentage of viable cells was 95% (not shown). Diagrams (B) show inhibition of doxorubicin- and dexamethasone-induced apoptosis by IL-7 investigated in 16 and 46 T-ALL samples, respectively. Each individual leukemic sample is presented as a point, positioned according to the value of drug-specific apoptosis in the absence (x-axis) and presence (y-axis) of IL-7.