Fig. 7
Single cycle replication of MCMV based vector vaccine is sufficient to induce anti-tumor effects in prophylactic and therapeutic settings. a. Mice were vaccinated IP with 1 × 106 PFU MCMV-M79-FKBP-E7 or control virus (MCMV-M79-FKBP-gB). Splenocytes were harvested 4, 21 weeks and 13 months after vaccination and stimulated with dominant peptide of E7 or pooled E7 peptides for 36 h (a). IFN-γ production was measured by ELISPOT assay. Shown is the number of spots per 5 × 105 cells ± SEM. b Frequency of E749–57-specific CD8+ T cells within total CD8+ T cell population at 4, 21 weeks and 13 months post vaccination. Data represents mean values ± SEM (n = 5 mice per group). c KLRG1 and CD127 marker expression on E7-specific CD8+ T cells at day 7 and 60 post vaccination with MCMV-M79-FKBP-E7. d TC-1 tumor outgrowth of the mice that were vaccinated with 1 × 106 PFU MCMV-M79-FKBP-E7 or control virus MCMV-M79-FKBP-gB at 4, 21 weeks and 13 months before tumor challenge. Tumor out growth was followed for 23 or 40 days. e and f C3 tumor outgrowth of the mice were infected with 1 × 105 PFU MCMV-IE2-OVA via IN route or kept uninfected. After 35 days, the mice were vaccinated with 1 × 106 PFU MCMV-M79-FKBP IP or kept unvaccinated. Mice were challenged with C3 tumor cells after 35 days. Tumor outgrowth was followed for 60 days (e). The number of tumor-free mice from the total mice is indicated above each tumor out growth graph. f The percentage of E7-specific CD8+ T cells within the total CD8+ T cell population in the blood (y-axis) plotted against the E7-specific CD8+ T cell response ranked from low to high (x-axis) of the mice that were either tumor-free (tumor-) or tumor positive (tumor+) (f). g Mice were challenged with TC-1 tumor cells, and after 8 days when tumors were palpable mice were treated with 1 × 106 PFU MCMV-m79-FKBP-E7 or control virus MCMV-m79-FKBP-gB via IP, 1 × 105 PFU MCMV-IE2-E7 via IP or 5 × 105 PFU MCMV-IE2-E7 via SC or kept unvaccinated. Tumor out growth was followed for 40 days. The number of tumor-free mice from the total mice is indicated. Data are representative of two independent experiments with similar results