Protection of Jurkat J-27 T cells from AICD by vitamin E. (a and b) Vitamin E prevents apoptosis in J-27 T cells. J-27 T cells were induced either with PMA and ionomycin (iono.) or with plate-bound α-CD3 for 24 hours in the presence of vitamin E or equal amounts of the vitamin E solvent ethanol. Apoptotic nuclei were measured by determination of DNA fragmentation. (c) The CD95L blocker CD95Fc and NOK1 blocked AICD. J-27 cells were stimulated as above in the absence or presence of CD95Fc or NOK1 for 24 hours. (d) Vitamin E does not block α–APO-1–induced apoptosis. J-27 cells were treated without or with vitamin E and then treated with α–APO-1 antibody for the indicated times. Results are shown from one of three reproducible experiments done with duplicates. (e) Vitamin E downregulated CD95L mRNA expression in J-27 cells. J-27 T cells were cultured in the absence or presence of vitamin E and then stimulated by PMA and ionomycin for the indicated times. CD95L mRNA expression was analyzed by RT-PCR. IFN-γ and β-actin mRNA expression levels were examined for control. (f) Quantification of the CD95L mRNA expression levels by real-time PCR. RNA at 0, 1, 3, and 6 hours after stimulation was subjected to real-time PCR. The expression value of CD95L at time 0 was set as transcription value 1. The expression value of CD95L at the indicated times is shown as fold difference relative to that at time 0.