FIG 8.

T_REG cells induce CD39-dependent neutrophil apoptosis. (A) Example of the flow cytometry purification step for obtaining the splenic CD4⁺ CD25⁺ nT_REG cells used in the experiments for which results are shown in panels B to D. (B and C) Apoptotic response (B) and ROS production (C) of neutrophils under the indicated in vitro conditions. ARL, ARL 67156; CD4⁺, CD4⁺ CD25⁻ T cells; CD8⁺, CD8⁺ T cells; Los, losartan; PD, PD123319. Asterisks indicate significant differences (*, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001) from the control or between the indicated experimental groups (n = 4). (D) Effect of T_REG cell-derived culture supernatants on neutrophil chemotaxis (values obtained with medium alone were given an arbitrary value of 1). Asterisks indicate significant differences (*, P ≤ 0.05) from the control; NS, no significant difference (n = 4). (E) Example of the purification step used to obtain the splenic CD39⁺ and CD39⁻ nT_REG cells used in the experiment for which results are shown in panel F. (F to H) Apoptotic responses of neutrophils under the indicated culture conditions. CD39⁺, CD4⁺ CD25⁺ CD39⁺ nT_REG cells; CD39⁻, CD4⁺ CD25⁺ CD39⁻ nT_REG cells; α-CD3 and α-CD28, antibodies to mouse CD3 and CD28, respectively. Asterisks indicate significant differences (**, P ≤ 0.01; ***, P ≤ 0.001) from the control or between the indicated experimental groups (n = 4). (I) AngII-stimulated ROS production by neutrophils under the indicated culture conditions. Asterisks indicate significant differences (**, P ≤ 0.01) from the control (n = 4).