FIG 5.

Characterization of HPV antigen-specific CD8⁺ T cell-mediated immune responses and therapeutic antitumor effects of the various DNA vaccines in mice injected with HPV16 E6/E7-expressing tumors, model TC-1. Six- to eight-week-old female C57BL/6 mice (5 mice/group) were injected with 2 × 10⁵ of TC-1 cells subcutaneously on day 0. On day 3, the mice were vaccinated with either pBI-10.1, pBI-11, or pBI-12 DNA (25 μg/50 μl/mouse) through i.m. injection and boosted twice as indicated or left untreated as control. (A) Schema of the experiment. (B) Detection of HPV16 E7-specific CD8⁺ T cells in peripheral blood using HPV16 E7 (aa 49 to 57) peptide-loaded tetramer staining. (C) Detection of HPV18 E6-specific CD8⁺ T cells in peripheral blood using HPV18 E6 (aa 67 to 75) peptide-loaded tetramer staining. (D) Summary of the TC-1 tumor volumes of the mice. (E) Kaplan-Meier analysis of the survival of TC-1 tumor-bearing mice.