Lymphocytes from evolutive B-CLL express a high level of P2X₇R and are inhibited by ATP.

(A) RT-PCR amplification and detection were performed as described in “Study design”; 10 μL PCR product was loaded in each lane. Amplification products from 2 evolutive (E1 and E2) or indolent (I1 and I2) B-CLL patients are shown; human macrophages are shown as a control (Cont). In these same lymphocyte populations, increases in [Ca⁺⁺]_i ([Ca⁺⁺]_i) caused by stimulation with 1 mM ATP were also measured and reported below each lane. [Ca⁺⁺]_i increases are expressed as means ± SD of triplicate determinations. (B) β-actin amplification fragments. (C) Western blot with a specific anti-P2X₇ serum (see “Study design”). (D) Lymphocytes, 10⁶ per well, from 8 patients (4 B-CLL indolent and 4 B-CLL evolutive) were incubated as described in “Study design” for 24 hours in the presence or absence of 2.5 mM ATP. Data (cpm) are the means ± SD of quadruplicate determinations from a single experiment representative of 4 others. Statistical significance (P) between evolutive B-CLL incubated without or with ATP is reported above bars.