Fig 6.

Elimination of the WHcAg epitope-loaded cells from the spleen after DNA prime-AdV boost immunization. (A) The kinetics of WHcAg-specific CTL-mediated elimination of the WHcAg-derived peptide c13-21-loaded target cells at various time points after DNA immunization. (B and C) Comparison of the elimination of the target cells in mice immunized with DNA-AdV or only DNA. Mice were immunized two times with pCGWHc and boosted with Ad5WHc or pCGWHc. Mice immunized with empty pCG and Ad5GFP served as controls. At day 8 after the last immunization, mice were intravenously injected with the same number of target cells loaded with the CD8⁺ T-cell epitope c13-21 (black peak) and nonloaded cells (white peak) for the reference. After 8 h the mice were sacrificed, and the percentage of target cell killing was investigated in the spleen. Histograms of representative mouse from each immunization group exhibiting the highest killing activity are shown in panel B. In panel C the bars represent the mean values and standard errors of the means obtained from groups of six mice immunized with WHcAg-expressing vaccines and four control mice immunized with empty pCG plasmid in combination with Ad5GFP. The asterisks mark the statistically significant difference: *, <0.05; **, <0.005).