Fig. 7

Influenza infected aged mice had impaired and terminally exhausted CD8⁺ T cells. A Aged infected mice tended to lose more weight by day 9 p.i. B Aged mice produced fewer tet⁺ CD8⁺ T cells at day 7 p.i. C Representative flow plots of NP366 flu tetramer staining at day 7 p.i. D Aged CD8⁺ T cells failed to produce granzyme B. E Aged CD8⁺ T cells had no granzyme B functional tet⁺ T cells. F Representative granzyme B staining at day 7 p.i. G Aged mice accumulated more TCF⁻ TOX⁺ EOMES⁺ CD8⁺ T cells compared to young infected mice at day 7 p.i. H Representative staining of TOX⁺ EOMES⁺ CD8⁺ T cells. I Representative images of ELISpot. J Aged mice had minimal IFN production, *P < 0.05, **P < 0.01, ***P < 0.005, unpaired t-test