biostudies-literatureUnknown7Pangrazzi LNaïve CD8⁺ T cells are key players of adaptive immunity, but their heterogeneity and age-related changes are not fully understood. This study aimed to compare naïve CD8⁺ T cell subsets defined by different combinations of markers, namely, N_CCR7 (CD45RA⁺CCR7⁺), N_CD28 (CD45RA⁺CD28⁺), N_CD27 (CD45RA⁺CD27⁺), and phenotypically most "true-naïve"-like, N_TN (CD45RA⁺CCR7⁺CD28⁺CD27⁺CD57^-). Peripheral blood was harvested from donors of various ages and the phenotype of the four subsets of naïve CD8⁺ T cells was analyzed. N_CD27 and N_TN cells showed similar phenotypes with low expressioFrontiers in aging1765665https://www.ebi.ac.uk/biostudies/studies/S-EPMC12907349biostudies-literaturePhenotypic and functional heterogeneity of naive CD8<sup>+</sup> T cells in human peripheral blood during aging.PMC12907349Chelini GBachmann MPangrazzi LHoffmann LJenewein BWeinberger BPehl PKeller MCavinato MfalsePhenotypic and functional heterogeneity of naive CD8<sup>+</sup> T cells in human peripheral blood during aging.Naïve CD8⁺ T cells are key players of adaptive immunity, but their heterogeneity and age-related changes are not fully understood. This study aimed to compare naïve CD8⁺ T cell subsets defined by different combinations of markers, namely, N_CCR7 (CD45RA⁺CCR7⁺), N_CD28 (CD45RA⁺CD28⁺), N_CD27 (CD45RA⁺CD27⁺), and phenotypically most "true-naïve"-like, N_TN (CD45RA⁺CCR7⁺CD28⁺CD27⁺CD57^-). Peripheral blood was harvested from donors of various ages and the phenotype of the four subsets of naïve CD8⁺ T cells was analyzed. N_CD27 and N_TN cells showed similar phenotypes with low expressio2026-01-01T00:00:00Z20262026-07-10T03:11:51.422Z2026-07-10T03:08:43.715ZS-EPMC129073494170467910.3389/fragi.2026.1765665