title: Therapeutic effect of dendritic cells loaded with a fusion mRNA encoding tyrosinase-related protein 2 and enhanced green fluorescence protein on B16 melanoma.
abstract: Dendritic cells (DCs) loaded with messenger RNA (mRNA) have been proposed to be useful for inducing specific cytotoxic T lymphocytes against tumor antigens. It is now also apparent that tumor antigen-specific T cell tolerance limits the efficacy of active immunotherapy. To improve the efficacy of mRNA-loaded DCs, we constructed a fusion mRNA encoding tyrosinase-related protein 2 (TRP2), which has a late endosomal/lysosomal sorting signal and enhanced green fluorescence protein (EGFP), and evaluated its effect in a murine melanoma model. C57BL/6 mice were challenged subcutaneously (s.c.) with 3 x 10(5) B16 tumor cells, and 3 and 10 days later, 3 x 10(5) DCs loaded with mRNA (DC/mRNA) were injected s.c. in the vicinity of the tumor site. Treatment with DC/TRP2 mRNA or DC/TRP2-EGFP mRNA significantly inhibited tumor growth compared to DC/PBS on day 17 after B16 challenge (DC/PBS vs. DC/TRP2 mRNA, p = 0.0411; DC/PBS vs.DC/TRP2-EGFP mRNA, p = 0.0253), whereas no antitumor effect was observed in mice treated with DC/EGFP mRNA or DC/TRP2 peptide. Moreover, the survival rate in mice immunized with DC/TRP2 mRNA or DC/TRP2-EGFP mRNA was significantly improved as compared with that in mice receiving DC/PBS (DC/PBS vs. DC/TRP2 mRNA, p = 0.0228; DC/PBS vs. DC/TRP2-EGFP mRNA, p = 0.0049). Depletion of CD4+ T cells or CD8+ T cells with antibody administration completely abrogated the therapeutic effectiveness of DC/TRP2-EGFP mRNA, suggesting the induction of a T cell immune response against the B16 tumor.
authors.affiliation: Department of Clinical Laboratory Science, Yamaguchi University School of Medicine, 1-1-1, Minami Kogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Mikiko
authors.initials: M
authors.lastname: Fukui
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nakano-Hashimoto
authors.forename: Kozue
authors.initials: K
authors.lastname: Okano
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Maruta
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Suehiro
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Hamanaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamashita
authors.forename: Kohzoh
authors.initials: K
authors.lastname: Imai
authors.forename: Michio M
authors.initials: MM
authors.lastname: Kawano
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hinoda
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000951:Antigens, Neoplasm; D019677:Artificial Gene Fusion; D003713:Dendritic Cells; D004195:Disease Models, Animal; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics*; D007167:Immunotherapy / Q000379:methods; D019746:Intramolecular Oxidoreductases / Q000235:genetics* / Q000494:pharmacology; D008545:Melanoma / Q000276:immunology* / Q000473:pathology / Q000628:therapy* / Q000662:veterinary; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction; D012878:Skin Neoplasms / Q000276:immunology* / Q000473:pathology / Q000628:therapy* / Q000662:veterinary; D016019:Survival Analysis; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014162:Transfection
chemical_list: D000951:Antigens, Neoplasm; D012333:RNA, Messenger; D049452:Green Fluorescent Proteins; D019746:Intramolecular Oxidoreductases; C042501:dopachrome isomerase