Figure 5.

Protective efficacy in the absence of circulating T cells. BALB/c mice were vaccinated i.n. or i.m. with Ad4T1 (10⁷ IU) + AdIL1β (2.5×10⁶ IU) and challenged with 4T1-luc cells intravenously 35 days later. The animals received FTY720-supplemented drinking water (2 µg/mL) 3 days before the tumor challenge to inhibit T cell circulation and the treatment was continued throughout the experiment (A). Number of CD8⁺ T cells in the blood of FTY720-treated animals compared with untreated animals was determined by flow cytometry analysis (B). Survival analysis over an 8-week period (C). Corresponding bioimaging (D) with quantification of luciferase signal at the 2-week time point (E). The background signal is shown as a dashed line. Statistical significances were determined using Mann-Whitney test (B, E) and Gehan-Breslow-Wilcoxon-test (C). All groups n=6 (total 12 animals). P values indicate significant differences (*p<0.05; **p<0.005; only statistically significant comparisons shown). i.m., intramuscular; i.n., intranasal; IU, infectious units; iv, intravenous.