CT-2S 
(Sxl^dulkaje) 
CMW BENCA 
(2x10* chillexjc) (kl0‘dxlltasO 
WP-4 
CLdfl r cKiIkosc) 
Figure 3. Immunogenicity of irradiated, non-transduced murine tumor cells. 
Animals were vaccinated with irradiated, wild-type tumor as indicated. Three 
weeks later they were challenged by the subcutaneous injection of live, wild- 
type tumor cells, o animals displaying growth of tumor challenge. • animals 
protected against challenge. 
Since irradiated wild-type tumor cells possessed significant immunogenic 
activities, it was not a simple matter to examine the added effects of GM-CSF 
or other cytokines. However, a lengthy exploration of vaccine cell dose and 
tumor cell challenge size in each tumor system resulted in defining 
experimental conditions which permitted valid comparisons of the immunogenic 
potency of irradiated, non-transduced tumor cells with similarly prepared 
cells secreting GM-CSF. Although the relative efficacy of GM-CSF secreting 
cells varied somewhat, in all models examined they were more potent 
stimulators of a systemic immune response than their counterpart, non- 
transduced cells (Figure 4). 
Recombinant DNA Research, Volume 17 
[297] 
