FIG 3.
Identification of H2d-specific CTL epitopes in PA. (A) BALB/c mice were immunized with Ad5-PAopt twice, at an interval of 4 weeks. Splenocytes were harvested 10 days after the second immunization and restimulated in vitro with the predicted peptides from PA for use in a cytokine staining assay. Cells restimulated with purified rPA and a negative control without peptide were included. (B and C) To further confirm that the peptide identified in the cytokine staining assay was PA specific, splenocytes from BALB/c mice immunized with Ad5-PAopt or Ad5-EGFP (as a control) twice were restimulated in vitro with NA-9 or without peptides, and the responding CD8+ T cells were visualized by intracellular IFN-γ staining. The data are presented as the means ± SEM (n = 6 per group).