title: Therapeutic tumor immunity induced by polyimmunization with melanoma antigens gp100 and TRP-2.
abstract: To improve the immunogenicity of melanoma self-antigens, we used a novel strategy of nonviral genetic vaccination coupled with muscle electroporation. Electroporation-enhanced immunization with plasmids encoding either human gp100 or mouse TRP-2 antigens induced only partial rejection of B16 melanoma challenge. However, immunization with a combination of these two antigens caused tumor rejection in 100% of the immunized mice. Splenocytes from combination-immunized animals killed syngeneic targets loaded with peptides derived from both gp100 and TRP-2. Immune cell depletion experiments identified CD8+ T lymphocytes as the primary effectors of antitumor immunity. Most importantly, polyimmunization led to the generation of a therapeutic immune response that significantly improved the mean survival time of mice bearing established lung metastases. These results validated the usefulness of electroporation-enhanced, nonviral genetic immunization for the active immunotherapy of cancer and indicated that using a combination of different tumor antigens may be a decisive strategy for a successful therapeutic vaccination.
authors.affiliation: Valentis, Inc, The Woodlands, Texas 77381-4248, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Mendiratta
authors.forename: G
authors.initials: G
authors.lastname: Thai
authors.forename: N K
authors.initials: NK
authors.lastname: Eslahi
authors.forename: N M
authors.initials: NM
authors.lastname: Thull
authors.forename: M
authors.initials: M
authors.lastname: Matar
authors.forename: V
authors.initials: V
authors.lastname: Bronte
authors.forename: F
authors.initials: F
authors.lastname: Pericle
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000235:genetics / Q000276:immunology*; D019496:Cancer Vaccines / Q000235:genetics / Q000276:immunology* / Q000627:therapeutic use; D018274:Electroporation; D005260:Female; D019746:Intramolecular Oxidoreductases / Q000235:genetics / Q000276:immunology*; D008175:Lung Neoplasms / Q000276:immunology / Q000556:secondary / Q000628:therapy; D008546:Melanoma, Experimental / Q000276:immunology* / Q000517:prevention & control / Q000556:secondary / Q000628:therapy*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009363:Neoplasm Proteins / Q000235:genetics / Q000276:immunology*; D009368:Neoplasm Transplantation; D010957:Plasmids / Q000008:administration & dosage / Q000235:genetics; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014407:Tumor Cells, Cultured; D017778:Vaccines, Combined / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use; D058951:gp100 Melanoma Antigen
chemical_list: D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; C548637:PMEL protein, human; C548642:Pmel protein, mouse; D017778:Vaccines, Combined; D058951:gp100 Melanoma Antigen; D019746:Intramolecular Oxidoreductases; C042501:dopachrome isomerase