Two distinct subpopulations of human stem-like memory T cells exhibit complementary roles in self-renewal and clonal longevity
Fig 5
CD95hi cells have a lower TREC content and their frequency increases with age.
(A) TREC (T-cell receptor excision circle) content was quantified by ddPCR for FACS-sorted T cell subpopulations from N = 7 healthy donors, from Cohort 4. Boxplots indicate the number of TREC copies per cell for each subset (bars represents the median, the box the interquartile range (IQR) and whiskers show lower quartile − 1.5 * IQR and upper quartile + 1.5 * IQR; all data points, including outliers, are shown by circles). Graph on right is a zoom in (truncated y axis) to show TREC content of memory populations more clearly. Statistics: Wilcoxon paired test (B) PBMCs isolated from the blood of 21 healthy individuals (23−65 yrs, Cohort 4) were stained to identify CD95hi and CD95int TSCM cells. The percentage of TSCM that were CD95hi (orange circles) and CD95int (blue circles) was quantified. The results are plotted against the age of the donor. We found that the proportion of TSCM that were CD95hi increased significantly with age (Rs = 0.82, P = 6.78 × 10−6 Spearman). The data underlying this figure can be found in S1 Data.