title: Tumor mRNA-loaded dendritic cells elicit tumor-specific CD8(+) cytotoxic T cells in patients with malignant glioma.
abstract: In this study, we demonstrate that tumor mRNA-loaded dendritic cells can elicit a specific CD8(+) cytotoxic T-lymphocyte (CTL) response against autologous tumor cells in patients with malignant glioma. CTLs from three patients expressed strong cytolytic activity against autologous glioma cells, did not lyse autologous lymphoblasts or EBV-transformed cell lines, and were variably cytotoxic against the NK-sensitive cell line K-562. Also, DCs-pulsed normal brain mRNA failed to induce cytolytic activity against autologous glioma cells, suggesting the lack of autoimmune response. Two patients' CD8(+) T cells expressed a modest cytotoxicity against autologous glioma cells. CD8(+) T cells isolated during these ineffective primings secreted large amounts of IL-10 and smaller amounts of IFN-gamma as detected by ELISA. Type 2 bias in the CD8(+) T-cell response accounts for the lack of cytotoxic effector function from these patients. Cytotoxicity against autologous glioma cells could be significantly inhibited by anti-HLA class I antibody. These data demonstrate that tumor mRNA-loaded DC can be an effective tool in inducing glioma-specific CD8(+) CTLs able to kill autologous glioma cells in vitro. However, high levels of tumor-specific tolerance in some patients may account for a significant barrier to therapeutic vaccination. These results may have important implications for the treatment of malignant glioma patients with immunotherapy. DCs transfected with total tumor RNA may represent a method for inducing immune responses against the entire repertoire of glioma antigens.
authors.affiliation: Department of Neurosurgery, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata City 951-8585, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Ryuya
authors.initials: R
authors.lastname: Yamanaka
authors.forename: Junpei
authors.initials: J
authors.lastname: Homma
authors.forename: Naoto
authors.initials: N
authors.lastname: Tsuchiya
authors.forename: Naoki
authors.initials: N
authors.lastname: Yajima
authors.forename: Seiichi
authors.initials: S
authors.lastname: Yoshida
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000235:genetics / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002461:Cell Line, Transformed; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005910:Glioma / Q000235:genetics / Q000276:immunology*; D049452:Green Fluorescent Proteins; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D016130:Immunophenotyping; D008164:Luminescent Proteins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014407:Tumor Cells, Cultured
chemical_list: D016207:Cytokines; D015395:Histocompatibility Antigens Class I; D008164:Luminescent Proteins; D012333:RNA, Messenger; D049452:Green Fluorescent Proteins