FIG. 8.

Cytotoxic responses induced by vaccination with Ad encoding HBsAg/E7 fusion proteins determined by antigen-specific kill of indicator cell populations. C57BL/6 mice (n = 10 per group) were immunized at 2-week intervals with Ad-HBsAg(S)16EE7Δ49-57, Ad-16E7wt, or recombinant HBsAg(S)16E7Δ49-57 VLPs. Six days after the fourth boost immunization, splenocytes from naïve mice were loaded with either E7(49-57) or HBsAg(S)(208-215) peptides or left unloaded and subsequently labeled with CFSE to low, high, and intermediate concentrations, respectively. Equal amounts of labeled cells were mixed, and 15 × 10⁶ cells of the mixture was injected intravenously into control naïve and vaccinated mice. Lymphocytes from spleens and regional lymph nodes were taken 20 h after injection and analyzed by flow cytometry. Represented are the mean percentages ± standard deviations of specific CTL activities in the different groups of mice calculated as described in Materials and Methods.