Effect of vitamin E on AICD of peripheral blood lymphocytes of HIV-positive individuals. (a) AICD is increased in HIV-infected individuals. Peripheral blood T lymphocytes from 33 HIV-positive individuals and 11 uninfected donors were stimulated with plate-bound α-CD3 for 48 hours. Apoptosis was assessed by FSC/SSC analysis. The mean difference between patients and uninfected individuals is –7.23. The 95% confidence interval is –13.7 to –2.12. (b and c) Vitamin E prevents AICD of T lymphocytes of HIV-positive individuals. Freshly isolated blood T lymphocytes from 31 HIV-positive individuals were individually stimulated with plate-bound α-CD3 in the absence (x axis) or presence (y axis) of either CD95Fc (b, 27 patients) or vitamin E (c, 24 patients) as indicated. IgG1 was used as control. Cell death was assessed after 48 hours’ stimulation and subjected to statistical analysis. (d) Comparison of CD95Fc- and vitamin E–mediated inhibition of α-CD3–induced specific cell death of HIV-positive individuals. AICD from 22 of 31 HIV-positive individuals tested was downregulated in the presence of either CD95Fc or vitamin E. Results are presented as percent inhibition of α-CD3–induced specific cell death by CD95Fc or by vitamin E.