RBCs reduce the percentage of apoptotic T cells after mitogenic activation.

PBLs were stimulated with PHA and cultured in the absence or presence of RBCs for 1 to 3 days. Cell surface expression of externalized phosphatidylserine by activated T cells was determined by Annexin V-FITC binding. Histograms show Annexin V⁺ cells gated among PI⁻ cells at days 1, 2, and 3 after activation of PBLs in the absence or presence of RBCs. Annexin V labeling of resting PBL was less than 2%. Data from 1 of 4 separate experiments with similar results are shown.