Figure 2.

DNA vaccine pEKL6 elicits CTL and ADCC responses in HLA-A2 Tg mice. A. HLA-A2 Tg mice (n = 12 per group) were I.M. immunized twice with the indicated DNA vaccines. Spleen cells from DNA-vaccinated mice were stimulated with irradiated EL4-L6-A2 or EL4-L6 cells (2×10⁴) for 2 hours. After stimulation, the percentage of CD107a⁺ CD8⁺ cells was calculated as EL4-L6-A2-stimulated group (%)-EL4-L6-stimulated group (%). B. Spleen cells were harvested from the DNA-immunized mice and stimulated with 10 μg/ml indicated peptides for 48 h. IFN-γ-secreting cells were determined using an IFN-γ ELISPOT assay. Data are presented as the means ± SD. ***P < 0.001. C. CD8⁺ T cells specific to HLA-A2-restricted TAL6 peptide A2-5 were measured using PE-conjugated A2-5 tetramers. D. TAL6-specific ADCC was determined in a ⁵¹Cr release assay. The lysis percentage was calculated as immunized serum (lysis %) - naïve serum (lysis %). The results obtained are expressed as the mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001.