Figure 6

Cross-presentation of naturally processed apoptotic epitopes to the related CD8 ⁺ T _EM cells by dendritic cells. (A) One representative of five experiments in which peripheral blood mononuclear cells from one MS patient were double-stained with mAb to CD8 and dextramers complexed with the indicated apoptotic epitope. These cells were then cultured with autologous dendritic cells (DCs) that had been pulsed or not with the relevant soluble peptide, apoptotic cloned T cells (ACs = apoptotic cells), ACs previously treated with a negative caspase control (Ctr = Z-FA-FMK), or ACs previously treated with the caspase 3 inhibitor (C3I = Z-DEVD-FMK). After 18 h, CD8⁺dextramer⁺ cells were tested for their capacity to produce the different cytokines indicated by the intracellular staining assay. Dot plots are gated on CD8⁺dextramer⁺ cells and show percentages of the different cytokine-producing cells in each quadrant. (B) Cumulative experiments in five independent patients, performed as described in (A), showing the mean percentages of cells producing IL-17 (solid bars) and IFN-γ (open bars) in CD8⁺dextramer⁺ cells in response to the indicated stimuli: autologous DCs alone; DCs pulsed with the vimentin (VIME)_78-87 peptide; DCs pulsed with ACs, which had been previously treated with a negative caspase control (Z-FA-FMK); or DCs pulsed with ACs, which had been previously treated with the C3I (Z-DEVD-FMK).