title: Local tumor irradiation augments the antitumor effect of cytokine-producing autologous cancer cell vaccines in a murine glioma model.
abstract: The combined therapeutic effect of cytokine-producing cancer cell vaccines and local radiotherapy was studied in a mouse glioma 261 (GI261) brain tumor model. Brain tumor-bearing mice were treated with cytokine (IL -4, IL-6, IL-7, GM-CSF, TNF-alpha, LIF, LT) producing vaccines made by in vitro transduction of GI261 cells with the corresponding adenoviral vectors. Vaccines producing either IL-4 or GM-CSF cured 20-40% of mice. The antitumor effect strongly depended on the secreted cytokine level. Vaccination therapy induced specific activation of cytotoxic T lymphocytes measured by cell-mediated cytotoxicity assay. Brain tumors were heavily infiltrated by CD4+ lymphocytes after treatment with IL-4- or GM-CSF-secreting cells. GM-CSF vaccination induced moderate CD8+ infiltration, as well. Depleting either CD4+ or CD8+ lymphocyte subsets abolished the anticancer effect of GM-CSF-expressing cells. Strong synergism was observed by combining cytokine vaccination (GM-CSF, IL-4, IL-12) with local tumor irradiation: about 80-100% of the glioma-bearing mice was cured. The high efficiency of combined treatment was maintained even under suboptimal conditions when neither of the modalities cured any of the mice alone. This suggests that vaccination therapy might open a new potential in the clinical treatment of high-grade gliomas when applied as adjuvant to existing treatment modalities.
authors.affiliation: Department of Molecular and Tumor Radiobiology, National Research Institute for Radiobiology and Radiohygiene, Budapest, Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Lumniczky
authors.forename: Szilvia
authors.initials: S
authors.lastname: Desaknai
authors.forename: Laszlo
authors.initials: L
authors.lastname: Mangel
authors.forename: Bela
authors.initials: B
authors.lastname: Szende
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Hamada
authors.forename: Egon J
authors.initials: EJ
authors.lastname: Hidvegi
authors.forename: Geza
authors.initials: G
authors.lastname: Safrany
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000532:radiotherapy*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D019496:Cancer Vaccines / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D003602:Cytotoxicity, Immunologic; D005822:Genetic Vectors; D005910:Glioma / Q000188:drug therapy* / Q000276:immunology / Q000532:radiotherapy*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014611:Vaccination
chemical_list: D019496:Cancer Vaccines; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor