Vaccination against the self-tumor associated antigen protein D52 (TPD52)

Abstract

Tumor protein 052 (052) is an intracellular tumor-associated self-protein that is frequently over-expressed in human cancers. The unique characteristics and distribution of 052 make it a worthwhile target for cancer vaccine study. To examine the capacity of this protein to function as a cancer vaccine, immunocompetent DBA/2 mice were immunized with the murine orthologue of human 052, mD52, as a plasmid DNA-based vaccine or as a protein vaccine in combination with oligodeoxynucleotide (ODN). The vaccinated mice were challenged with syngeneic P815 tumor cells, a murine mastocytoma that naturally over-expresses mD52 and monitored for subcutaneous tumor growth. We hypothesize that immunization with mD52 will provide a significant delay to onset of tumor growth as compared to control immunizations. The ideal challenge dose of P815 tumor cells was determined empirically and ubcutaneous P815 tumor formation was evaluated following vaccination. Fifty s percent of mice immunized with m052 protein admixed with ODN remained tumor-free 31 days post-challenge (2/4) while only 10 percent of control mice remained tumor-free (1/10). These data suggest that vaccination with mD52- protein-based vaccines prolongs tumor-free survival following challenge with P815 tumor cells.