CD8 T-cell memory is maintained by DCs. (A) Cell-cycle analysis of intermediate-density CD8 T cells from unmanipulated mice before and after incubation under the indicated conditions for 48 hours. The numbers represent the percentage of cells in the different regions. (B) Cell-cycle analysis of intermediate-density CD8 T cells from unmanipulated mice before and after incubation under the indicated conditions for 48 hours. (C-D) RNA levels of high-density (blue line) and intermediate-density (red line) gp33-41 tetramer-positive CD8 T cells from mice previously infected with LCMV, before and after incubation under the indicated conditions for 48 hours. The dashed blue line in the 48-hour panels represents the solid blue line for high-density T cells shown at time 0, and is shown to facilitate comparison with intermediate-density RNA levels. (E) IFN-γ production by high-density or intermediate-density tetramer-positive or CD8 T cells from mice previously infected with LCMV in response to PMA/Iono before and after 48 hours of incubation under the indicated conditions. Shaded histograms represent IFN-γ production by unstimulated cells.