title: Strategies for antigen choice and priming of dendritic cells influence the polarization and efficacy of antitumor T-cell responses in dendritic cell-based cancer vaccination.
abstract: Dendritic cells (DCs) primed with tumor antigens (Ags) can stimulate tumor rejection. This study was aimed at evaluating the polarization of T-cell responses using various DC Ag-priming strategies for vaccination purposes. DCs cocultured with irradiated "apoptotic" tumor cells, DC-tumor fusions, and DCs pulsed with freeze-thaw tumor lysate Ags served as Ag-primed DCs, with EG7 tumor cells (class II negative) expressing OVA as the model Ag. DCs loaded with class I- and class II-restricted OVA synthetic peptides served as controls. Primed DCs were assessed by the in vitro activation of B3Z OVA-specific CD8 T cells and the proliferation of OVA-specific CD8 and CD4 T cells from OT-I and OT-II TCR transgenic mice, respectively. In vivo responses were measured by tumor regression following treatment with Ag-primed DCs and by CTL assays. Quantification of IL-2, IL-4, IL-5, IFN-gamma, and TNF-alpha by cytometric bead array (CBA) assay determined the polarization of TH1/TH2 responses, whereas H-2 Kb/SIINFEKL tetramers monitored the expansion of OVA-specific T cells. DC-EG7 hybrids stimulated both efficient class I and class II OVA responses, showing that DC-tumor hybrids are also capable of class II cross-presentation. The hybrids also induced the most potent CTLs, offered the highest protection against established EG7 tumors and also induced the highest stimulation of IFN-gamma and TNF-alpha production. DCs cocultured with irradiated EG7 were also effective at inducing OVA-specific responses, however with slightly reduced potency to those evoked by the hybrids. DCs loaded with lysates Ags were much less efficient at stimulating any of the OVA-specific T-cell responses, showed very little antitumor protection, and stimulated a weak TH1 response, overbalanced by an IL-5 TH2 response. The strategy of Ag-loading clearly influences the ability of DCs to polarize T cells for a TH1/TH2 response and thus determines the outcome of the elicited immune response, during various vaccination protocols.
authors.affiliation: Department of Molecular Medicine, GKT School of Medicine, King's College London, The Rayne Institute, 123 Coldharbour Lane, SE5 9NU, London, UK. joanna.galea-lauri@kcl.ac.uk
authors.forename: Joanna
authors.initials: J
authors.lastname: Galea-Lauri
authors.forename: James W
authors.initials: JW
authors.lastname: Wells
authors.forename: David
authors.initials: D
authors.lastname: Darling
authors.forename: Phillip
authors.initials: P
authors.lastname: Harrison
authors.forename: Farzin
authors.initials: F
authors.lastname: Farzaneh
mesh_terms: D000818:Animals; D000941:Antigens / Q000737:chemistry; D000951:Antigens, Neoplasm / Q000737:chemistry*; D017209:Apoptosis; D016827:CD8 Antigens / Q000096:biosynthesis; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D019496:Cancer Vaccines; D002455:Cell Division; D045744:Cell Line, Tumor; D002469:Cell Separation; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D005434:Flow Cytometry; D007371:Interferon-gamma / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D015848:Interleukin-5 / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D018417:Th1 Cells; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000941:Antigens; D000951:Antigens, Neoplasm; D016827:CD8 Antigens; D019496:Cancer Vaccines; D016207:Cytokines; D007376:Interleukin-2; D015848:Interleukin-5; D010455:Peptides; D011993:Recombinant Fusion Proteins; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D007371:Interferon-gamma; D010047:Ovalbumin