Figure 6. Characterization of the role of T cell subset in the antitumor immunity generated by pcDNA3-HPV18-E6 DNA vaccine.
To determine the role of T cell subset, specifically the role of CD4+ or CD8+ T cells in the antitumor immunity generated by pcDNA3-HPV18-E6 DNA vaccine, forty 5~8 weeks old female C57BL/6 mice were divided into 4 groups (10 mice/group). Three groups of mice were immunized with 50 μg/mouse of pcDNA3-HPV18-E6 through IM injection followed by electroporation three times with 1-week interval. On the day of the third vaccination, one group of vaccinated mice was injected with anti-CD4 monoclonal antibody, and another group of immunized mice was injected with anti-CD8 monoclonal antibody through intraperitoneal injection for 3 days followed by once a week injection. 7 days after the last vaccination, all the mice were challenged subcutaneously with 1×105/mouse of TC-1/HPV18-E6 tumor cells. Tumor growth was monitored by measurement with a digital caliper twice a week. Survival of the mice was monitored every other day. A. TC-1/HPV18-E6 tumor growth curve. B. Survival curve of TC-1/HPV18-E6 tumor-bearing mice. Data are represented as mean ± SD. p-values were calculated by 2-tailed Student’s t test or log rank test. * = p<0.05; *** = p<0.001.