Fig. 4

Aged T cells transplanted into young mice recapitulated aged CD8⁺ T cell phenotype. A Syngeneic transplant experimental design. Lethally irradiated CD45.2 aged mice were reconstituted with T lymphocytes from young or aged CD45.1 donors, young B cells, and Rag1^−/− BM. B, C Aged mice that received young T lymphocytes (i.e. Y_T—> A_H) had improved CD8⁺ tetramer⁺ response compared to A_T—> A_H control. A_T—> Y_H had a diminished tetramer response compared to Y_T—> Y_H D Representative flow plots of tetramer staining. E Combinatorial analysis of PD-1, TIM-3, LAG-3, and 2B4 inhibitory receptors revealed that Y_T—> A_H had increased percent of CD8⁺ T cells that expressed 0 inhibitory receptors and decreased percent of CD8⁺ T cells that expressed at least 1 inhibitory receptor compared to A_T—> A_H. F Percentage of CD8⁺ T cells expressing granzyme B. G Percent functional virus-specific CD8⁺ T cells was calculated by dividing the percentage of granzyme B⁺ CD8⁺ T cells by the percentage of tet⁺ cells. H Boolean analysis of polyfunctionality of CD8⁺ T cells. Functional markers measured: granzyme B, IFNγ, TNF, perforin, and CD107a. *P < 0.05, **P < 0.005, ****P < 0.0001, one-way ANOVA