Spontaneous T-cell apoptosis and IL-15 rescue of cord-blood CD8 T cells.

(A) Mean percentage ± SEM of spontaneous T-cell death defined by annexin-V–FITC staining within the CD4⁺ and CD8⁺ subsets in uninfected (■, n = 17) and congenitally infected (▪, n = 12) newborns. **P < .01 vs uninfected newborns (Student test). (B) Mean percentage ± SEM of spontaneous T-cell death following cell culture for one day in the presence or absence of IL-15. (C, D) Two representative experiments, in one uninfected (C) and one congenitally infected neonate (D) of the TUNEL assay analysis of spontaneous T-cell death are shown. Percentages of cellular spontaneous apoptosis are indicated in bold. #P < .05 vs unstimulated CBMCs (Student test).