FIG. 7.

Antitumor activities of armed MAV-1 vectors in the weakly immunogenic Pan02 xenograft tumor model. The DLFM vector was injected into Pan02 tumor-bearing animals, and tumor progression (A) and overall survival (B) were determined. Female C57BL/6 mice bearing Pan02 tumors (∼80 mm³) were injected weekly i.t. with the vehicle (PBS-10% [vol/vol] glycerol, n = 10), dlE102 (1 × 10⁷ PFU in a 50-μl volume, n = 9), or DLFM (1 × 10⁷ PFU in a 50-μl volume, n = 7). Tumor volume (A) was determined by caliper measurement and expressed as the mean tumor volume (cubic millimeters plus the standard error of the mean). In a separate study, Pan02 tumor-bearing mice were injected with two doses a week apart and 10 days later the mice were euthanized. The spleens were harvested, and the splenocytes were phenotyped by direct antibody staining and FACS analysis (C and D). The levels of activated T cells (CD44^hi/CD62L^low) in both the CD4⁺ (C) and CD8⁺ (D) subpopulations were determined. Differences between groups were analyzed by a one-way ANOVA with a Bonferroni correction (*, P < 0.5; **, P < 0.01; ***, P < 0.001).