Systemic rGM-CSF/rIL-4 enhanced the response to an adenoviral-based vaccine and led to antigen-specific retardation in tumor growth.
Mice were inoculated subcutaneously in the flank with 1 × 105 E-22 mouse thymoma cells that expressed theLacZ gene. Twenty-four hours later, osmotic pumps were implanted to deliver 7-day administration of either saline, rGM-CSF, or the combination of rGM-CSF/rIL-4 (10 μg each cytokine per day). Fourteen days after tumor inoculation, mice were immunized by intraperitoneal injection with 1 × 108 PFU of an adenoviral vector expressing either the LacZ transgene (ADV/β-gal) (B) or no transgene (AdV/RR5) (A). Tumor sizes (mm3) were measured twice a week, and data were presented as mean tumor size ± SE for 5 mice per group. *P < .05 compared with mice treated with either saline (not shown) or rGM-CSF. Tumor growth in mice treated with saline (not shown) was identical to that in mice receiving rGM-CSF. Representative experiment (n = 2).
