aDC depletion at 48 h p.i. results in increased apoptosis of IAV-specific CD8 T cells in the lungs. Groups of BALB/c mice were infected with a sublethal dose of IAV with or without aDC depletion as in Fig. 1. On days 4 and 5 p.i., mice were sacrificed and their lungs were analyzed by flow cytometry for apoptosis of tetramer⁺ CD8 T cells as measured by the frequency of active caspase 3/7⁺ (A, top; and B), active caspase 8⁺ (A, middle; and C), and annexin V⁺7-AAD^neg and annexin V⁺7-AAD⁺tetramer⁺ CD8 T cells (A, bottom; and D and E). Representative FACS plots from day 4 p.i. are gated on CD3⁺CD8⁺tetramer⁺ CD8 T cells. Data are representative of three to four separate experiments (n = 3–6 mice/group). Means ± SEM are shown.