Fig. 6.

In vivo cytotoxicity after vaccination with pCMV ECDTM plasmid in young and old mice. Plasmid-immunized mice were injected i.v with 5 × 10⁶ splenocytes (target cells) from naïve transgenic mice pulsed with either HER-2 immunodominant or irrelevant peptides and stained with CFSE as detailed in M&M. Sixteen hours later, the splenocytes of immunized mice were analyzed by flow cytometry. The value in each panel represents the percentage of CFSE high and CFSE low target cells remaining in the spleen in a representative sample. The histogram shows the mean ± SD of two independent experiments