Reduced melanoma tumor formation in mice immunized with DNA expressing themelanoma-specific antigen gp100/pmel17

Plasmid DNA encoding gene products of viruses or other pathogens has recent ly been applied by intramuscular injection as a novel type of vaccine. It c an induce cytotoxic T cell response in small animals and protect against ch allenge with influenza a viruses. Combinations with cytokines or DNA-encodi ng cytokines have been applied in order to increase the efficiency of prote ction. A DNA vaccine has been analyzed here against malignant melanoma enco ding gp100/pmeI17, a melanoma-associated antigen. A small animal model was used by injection of B16 melanoma cells to syngeneic C57BI/6 mice. DNA vacc ination before tumor cell challenge leads to about 50% reduction of tumor s ize. The cytokine gene coding for GMCSF did not increase the efficiency but also led to tumor size reduction when applied alone.