Fig. 5.

Immunization with E7 peptide formulated in DOTAP adjuvant elicits functional CD8⁺ T cells. a C57BL/6 mice were immunized sc with 10 μg E7 peptide formulated in DOTAP at low, optimal, overdose or in LPD on day 0 and day 10. Seven days after the last immunization, representative mice were injected iv with an equivalent amount of E7-pulsed (labeled with 4 μM CFSE) and non-pulsed (labeled with 0.4 μM CFSE) spleen cells from a syngenic donor. The spleen cells were harvested from the recipient mice 16 h later and the proportion of the CFSE^high and CFSE^low cells were analyzed by flow cytometry. b Percentage of specific anti-E7 killing was compared to that of the untreated control (n = 4) and was statistically analyzed by t-test (P < 0.01). c IFN-γ production by CD8⁺ cells after in vitro stimulation with E7 peptide. Seven days after the last immunization, the mice were killed and spleen cells were isolated. The total spleen cells were stimulated with 5 μg/ml E7 peptide for 6 h, followed by subsequent staining with surface CD8 marker and intracellular IFN-γ prior to FACS analysis. The numbers shown on contour plots represent the percentage of CD8⁺IFN-γ⁺ T cells gated on total CD8⁺ cells. Representative figures in the four experiments performed. d The numbers of CD8⁺IFN-γ⁺ cells per 10⁴ CD8⁺ T cells were shown as mean ± SD and were compared to that of the untreated control (n = 4, **P < 0.01)