Figure 2.
DNA vaccine primed T cells are functional. (a) Schematic representation of the vaccine administration, tetramer staining, target cells injection and specific killing analysis schedule in C57BL/6 mice. Mice were vaccinated intradermally with 10 or 100 µg of DNA (or a mix of peptides as positive control). SIINFEKL-specific responses were monitored in blood at different time points. To evaluate the killing capacity of the responses induced after vaccination, mice were injected with CFSE-labeled splenocytes loaded with minimal peptides and specific killing was analyzed two days later. (b) Kinetics of the SIINFEKL-specific CD8+ T cells responses induced by the vaccines, measured by SIINFEKL-H2-Kb tetramersand reported as percentage of total CD8+ T cells. (c). Representative flow cytometry histograms of CFSE-labeled antigen- or control peptide-loaded splenocytes detected in naïve and vaccinated mice. Two days after transfer, these target cells were detected in the spleen and specific killing was calculated. Percentages represent the relative proportions between cells loaded with an irrelevant control peptide (in gray) and target cells (white, orange, green or blue). (d) Specific killing by T cells in naïve mice versus mice vaccinated with DNA (10 or 100 µg) or peptide after transfer of antigen-loaded splenocytes. Error bars indicate mean ± SD.