FIG. 2.
Lipopeptides are presented by human dendritic cells to specific CD8+ T lymphocytes. (A) Flow cytometric analysis of surface CD8 and intracellular IFN-γ expression by Pol476-484-specific CD8+ T lymphocytes. A Pol476-484-specific CD8+ T-cell line was stimulated by HLA-A*0201 dendritic cells previously pulsed overnight with the irrelevant peptide Nef73-82 or with the peptide Pol476-484. Sample acquisition was performed on 10,000 events, gated on a scatter gate (R1) designed to include only viable lymphocytes (a) and a gate (R2) designed to include only CD8+ T cells (b). IFN-γ expression in viable, CD8+ T lymphocytes (R1*R2) is shown in dot plots c (irrelevant Nef peptide) and d (Pol peptide). (B) HLA-A*0201, HLA-A*0301-positive dendritic cells were incubated overnight with lipopeptides, peptides, or recombinant vaccinia viruses and then washed before being incubated with either the anti-Pol476-484 or the anti-Nef73-82CD8+ T-cell line. Expression of surface CD8-peridinin chlorophyll protein and intracellular IFN-γ-fluorescein isothiocyanate was quantified by flow cytometry analysis. The results show the ratio of IFN-γ-expressing cells in viable, CD8+ T cells. This experiment is representative of more than 10 independent experiments.