Differential effect of acadesine on B and T cells.

(A) Dose-response of the cytotoxic effect of acadesine on B and T cells from B-CLL patients. Cells were incubated with a range of doses of acadesine (up to 4 mM) for 24 hours. Viability was measured as nonapoptotic CD3⁺/CD19⁻ T cells (○,⋄) or CD3⁻/CD19⁺ B cells (●,♦) as described in “Patients, materials, and methods.” Two representative patients of 4 analyzed are shown. Viability is expressed as the percentage of the viability of nontreated cells. (B) Comparison between the induction of apoptosis in B and T cells (black bars and white bars, respectively) from B-CLL patients and healthy donors. Cells from 18 patients and 4 healthy donors were incubated with 0.5 mM acadesine for 24 hours. Viability is expressed as the mean value ± SD. (C) T cells from healthy donors were cultured with or without 0.5 mM acadesine for 3 hours and whole cell extracts were analyzed by Western blot with an antibody against phospho-AMPK (Thr172). As a control for AMPK activation, cells were incubated with 10 μM oligomycin for 3 hours in glucose-free medium. (D) Cells were cultured with or without 0.5 mM acadesine for 3 hours and intracellular levels of ZMP were measured by HPLC, as described in “Patients, materials, and methods.” Mean values ± SD from 5 B-CLL samples and 3 T-cell samples are shown.