RBCs reduce oxidative stress in activated human T cells.

(A) Resting human PBLs were activated with PHA for 3 days in the absence or presence of RBCs, as indicated. Cells were collected and stained with 5F6 mAb followed by rabbit-antimouse RPE immunoglobulins, and cells were acquired in a FACSort. Histograms show acrolein staining in resting (day 0, no PHA) and 3-day activated PBLs in the absence (PHA) or presence (PHA+RBC) of RBC. The percentage of acrolein-positive cells is indicated. (B) Resting human PBLs were activated with PHA-P (5 μg/mL) in CM in the absence or presence of RBCs for the times indicated. Activated T cells were harvested and stained with 5F6 mAb plus rabbit-antimouse RPE immunoglobulins and with Annexin V–FITC. Cells were immediately acquired in a FACSort. Dot blots show Annexin V versus acrolein fluorescence in activated T cells 1, 2, 4, and 24 hours after activation in the absence (PHA) or presence (PHA+RBC) of RBCs. One representative of at least 3 separate experiments is shown.