title: Induction of cytotoxic T lymphocytes against human cancer cell lines using dendritic cell-tumor cell hybrids generated by a newly developed electrofusion technique.
abstract: Recently, dendritic cells (DCs) and DC-tumor cell hybrids (DC-tumor hybrids) have been used for cancer vaccine therapy in a clinical trial. DC-tumor hybrids combine the potent antigen-presenting capacity of DCs with the ability to present all tumor antigens expressed on tumor cells to T cells. We used DC-tumor hybrids as stimulator cells to induce tumor-specific cytotoxic T lymphocytes (CTLs) in vitro. DC-tumor hybrids were generated from human monocyte-derived DCs and human cancer-cell lines (GT3TKB, lung cancer; GCIY, gastric cancer) by our newly developed electrofusion technique, established and refined with the use of mouse cells. To evaluate the capacity of DC-tumor hybrids generated by our method to induce tumor antigen-specific CTLs, we performed a cytotoxic assay and an interferon-gamma release assay using CD8-dominant effector lymphocytes induced by them. DC-tumor hybrids more effectively induced tumor-specific primary T-cell response than did stimulation with DCs co-cultured with irradiated tumor cells overnight, irradiated tumor cells alone, or a mixture of DCs and irradiated tumor cells. DC-tumor hybrids were generated at a high fusion rate by our electrofusion technique. When CTLs were induced by DC-tumor hybrids in vitro, the high fusion rate did not contribute to the induction of CTLs with increased tumor-specific cytotoxicity. The addition of interleukin-12 to the culture medium did not augment the cytotoxicity of CTLs. Overall, our results suggest that DC-tumor hybrids effectively induce human tumor-specific CTLs and may thus be applicable for clinical trials of adoptive immunotherapy.
authors.affiliation: Department of Surgery, Division of Digestive Surgery, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kyoto 602-8566, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Imura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ueda
authors.forename: Takashi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Itoh
authors.forename: Keiji
authors.initials: K
authors.lastname: Shimizu
authors.forename: Hidemasa
authors.initials: H
authors.lastname: Tamai
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Yano
authors.forename: Kei
authors.initials: K
authors.lastname: Naito
authors.forename: Junji
authors.initials: J
authors.lastname: Kohara
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nakane
authors.forename: Yuko
authors.initials: Y
authors.lastname: Matsuura
authors.forename: Atsuko
authors.initials: A
authors.lastname: Takeda
authors.forename: Takahisa
authors.initials: T
authors.lastname: Takeda
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kawai
authors.forename: Hisakazu
authors.initials: H
authors.lastname: Yamagishi
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology / Q000473:pathology; D000328:Adult; D000951:Antigens, Neoplasm / Q000276:immunology / Q000378:metabolism / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000494:pharmacology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002294:Carcinoma, Squamous Cell / Q000276:immunology / Q000473:pathology; D002459:Cell Fusion; D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D006822:Hybrid Cells / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D018664:Interleukin-12 / Q000494:pharmacology; D008175:Lung Neoplasms / Q000276:immunology* / Q000473:pathology; D008297:Male; D013274:Stomach Neoplasms / Q000276:immunology* / Q000473:pathology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014407:Tumor Cells, Cultured
chemical_list: D000951:Antigens, Neoplasm; D000970:Antineoplastic Agents; D018664:Interleukin-12; D007371:Interferon-gamma