Fig. 7: Memory T cell receptor diversity of antigen-specific T cells is maintained with aging.

A TCR diversity and clonality are shown as Shannon, Inverse Simpson, and Gini indices in antigen-specific CD8⁺ T cells mapping to the stem-like clusters (see Supplementary Fig. 6A). Only cells with TCRα and TCRβ sequences in single-cell sequencing data were used for the calculation. Due to low cell numbers, indices were calculated on the combined populations of all antigen-specific T cells with a stem-like phenotype (n = 7 Y and n = 7 O). B T cell diversity indices as in (A) but calculated on antigen-specific T cells with a memory phenotype. Data from older (O) individuals were contrasted to younger (Y) adults’ data described in Fig. 4F and Supplementary Fig. 6H. 7 Y and 7 O adults were assessed, but only samples with ≥20 cells were considered for this analysis. C Gini index as in (A) to estimate T cell clonality in antigen-specific T cells with a memory phenotype. Data from O individuals were contrasted to Y data described in Fig. 4F. 7 Y and 7 O adults were assessed, but only samples with ≥ 20 cells were considered for this analysis. D Clonal size distributions for each antigen specificity are shown as stacked bars for Y and O adults. E Numbers of distinct antigen-specific TCR chains ordered by decreasing clonal sizes plotted against the cumulative space they occupy. The number of distinct antigen-specific TCR chains from Y adults are as shown in Fig. 4G and are contrasted to results from O adults (dotted lines). All datapoints represent distinct biological replicates. Data show the mean ± SEM (A–C). Data were compared by two-tailed, unpaired ttests (A), or two-way ANOVA with Šídák’s multiple comparisons test (B, C). Source data are provided as a Source Data file.