Figure 2. H2^d-antigens stimulate LCMV-specific memory CD8 T cells to proliferate in vitro.

CFSE-labeled splenocytes from LCMV-immune B6 mice were cultured in vitro for 6 days with P815 cells (H2^d) as described in Materials and Methods. (A) After the in vitro culture, CD8 T cells were evaluated for division by dilution of CFSE, and the values shown represent the percentage of CD8 T cells that are CFSE^lo. (B) Cultured cells were incubated with either syngeneic (H2^b) or allogeneic (H2^d) splenocytes or with a mAb specific for CD3 for 5 hr and then evaluated for the production of IFN–γ̃ (C) Alternatively, cultured cells were incubated with the indicated peptides for 5 hr and then evaluated for the production of IFN–γ. For the intracellular cytokine assays, samples were gated on CD8⁺ cells, and the values shown represent the percentage of either CFSE^lo or CFSE^hi CD8 T cells staining positive for IFN–γ. The data are representative of 5 experiments.