title: Murine dendritic cells transfected with human GP100 elicit both antigen-specific CD8(+) and CD4(+) T-cell responses and are more effective than DNA vaccines at generating anti-tumor immunity.
abstract: Dendritic cells (DCs) are potent inducers of cytotoxic T lymphocytes (CTLs) when pulsed with an antigenic peptide or tumor lysate. In this report, we have used liposome-mediated gene transfer to examine the ability of plasmid DNA encoding the human melanoma-associated antigen gp100 to elicit CD8(+) and CD4(+) T-cell responses. We also compared the efficacy between gp100 gene-modified DCs and naked DNA (pCDNA3/gp100)-based vaccines at inducing anti-tumor immunity. DCs were generated from murine bone marrow and transfected in vitro with plasmid DNA containing the gp100 gene. These gp100-modified DCs (DC/gps) were used to stimulate syngeneic naive spleen T cells in vitro or to immunize mice in vivo. Antigen-specific, MHC-restricted CTLs were generated when DC/gps were used to prime T cells both in vitro and in vivo. Thus, these CTLs were cytolytic for gp100-transfected syngeneic (H-2(b)) tumor MCA106 (MCA/gp) and vaccinia-pMel17/gp100-infected syngeneic B16 and MCA106, but not parental tumor MCA106 and B16, or gp100-transfected allogeneic tumor P815 (H-2(d)). Immunization with DC/gp protected mice from subsequent challenge with MCA/gp but not parental MCA106. Antibody-mediated T-cell subset depletion experiments demonstrate that induction of CTLs in vivo is dependent on both CD4(+) and CD8(+) T cells. Furthermore, DC/gp immunization elicits an antigen-specific CD4(+) T-cell response, suggesting that DC/gps present MHC class II epitopes to CD4(+) T cells. In addition, our data show that gene-modified, DC-based vaccines are more effective than the naked DNA-based vaccines at eliciting anti-tumor immunity in both prophylactic and therapeutic models. These results suggest that the use of DCs transfected with plasmid DNA containing a gene for TAA may be superior to peptide-pulsed DCs and naked DNA-based vaccines for immunotherapy and could provide an alternative strategy for tumor vaccine design.
authors.affiliation: Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yang
authors.forename: C E
authors.initials: CE
authors.lastname: Vervaert
authors.forename: J
authors.initials: J
authors.lastname: Burch
authors.forename: J
authors.initials: J
authors.lastname: Grichnik
authors.forename: H F
authors.initials: HF
authors.lastname: Seigler
authors.forename: T L
authors.initials: TL
authors.lastname: Darrow
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D005260:Female; D007114:Immunization; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D009368:Neoplasm Transplantation / Q000276:immunology; D009374:Neoplasms, Experimental / Q000276:immunology* / Q000473:pathology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014162:Transfection; D019444:Vaccines, DNA / Q000276:immunology*; D058951:gp100 Melanoma Antigen
chemical_list: D000951:Antigens, Neoplasm; D000939:Epitopes; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; C548637:PMEL protein, human; C548642:Pmel protein, mouse; D019444:Vaccines, DNA; D058951:gp100 Melanoma Antigen