Fig. 5
Aged CD8+ T cells in Rag1−/− mice recapitulated aged immune response to HMPV. A CD8+ T cell adoptive transfer experimental design. Aged or young CD8+ T lymphocytes were isolated and adoptively transferred along with young CD4+ T and B lymphocytes into young Rag1−/− recipients. B, C Rag1−/− recipients with aged CD8+ T lymphocytes (i.e., ACD8 T—> YH) had a significantly diminished epitope-specific CD8+ T cell response compared to YCD8 T—> YH control. D Representative flow plots of tetramer staining. E–G ACD8 T—> YH produced less granzyme B and had fewer granzyme B functional CD8+ tet+ T cells. H–K ACD8 T—> YH had significantly fewer polyfunctional CD8+ T lymphocytes as measured by combinatorial analysis of cytokines/markers of degranulation and SPICE analysis. The percentage of functional virus-specific CD8+ tetramer+ cells was calculated by dividing the percentage of granzyme B+ CD8+ T cells by the percentage of tet+ cells. Functional markers measured: granzyme B, IFNγ, TNF, perforin, and CD107a. *P < 0.05, **P < 0.01, ***P < 0.005, unpaired t-test or one-way ANOVA