Differential expression of cell surface markers on responding CD4 T cells that either survive Fas ligation or become apoptotic.

Expression of TCR (Vα2), CD4, CD25, CD44, CD45RB, CD62L, and Fas was detected on responding T cells at day 3. Cells that were surviving Fas ligation (light gray open histograms) or becoming apoptotic (dark gray open histograms) were analyzed separately as explained in “Materials and methods.” Black histograms represent appropriate control stainings.