Contribution of CD95⁺CD28⁺, CD95⁺CD28⁻, and CD95⁻CD28⁺ to CD4⁺ or CD8⁺ T-cell subsets in young subjects compared with centenarians.

Data from 15 young subjects and 15 centenarians represent the means of different cell subpopulations in the 2 groups and were tested by analysis of variance (ANOVA). (A) In both CD4⁺and CD8⁺ subsets of centenarians, the percentage reduction of CD95⁻CD28⁺ (□) (P = .0001) was mirrored by an increase of CD95⁺CD28⁺ (▪) and CD95⁺CD28⁻ (▨) cells (P < .05 for both). (B) Considering absolute numbers among either CD4 or CD8 T cells, the counts of CD95⁺CD28⁺ did not change significantly. Thus, the loss of CD95⁻CD28⁺ cells was only associated with an increase of CD95⁺CD28⁻cells (P = .05 among CD4⁺ T cells, andP = .02 among CD8⁺ T cells).