title: Synergism between GM-CSF and IFNgamma: enhanced immunotherapy in mice with glioma.
abstract: Glioblastoma multiforme is the most common malignant primary brain tumor and also one of the most therapy-resistant tumors. Because of the dismal prognosis, various therapies modulating the immune system have been developed in experimental models. Previously, we have shown a 37-70% cure in a rat glioma model where rats were peripherally immunized with tumor cells producing IFNgamma. On the basis of these results, we wanted to investigate whether a combination of GM-CSF and IFNgamma could improve the therapeutic effect in a mouse glioma model, GL261 (GL-wt). Three biweekly intraperitoneal (i.p.) immunizations with irradiated GM-CSF-transduced GL261 cells (GL-GM) induced a 44% survival in mice with intracranial glioma. While treatment of GL-wt and GL-GM with IFNgamma in vitro induced upregulation of MHC I and MHC II on the tumor cells, it could not enhance survival after immunization. However, immunizations with GL-GM combined with recombinant IFNgamma at the immunization site synergistically enhanced survival with a cure rate of 88%. Tumors from mice receiving only 1 immunization on Day 10 after tumor inoculation were sectioned on Day 20 for analysis of leukocyte infiltration. Tumor volume was reduced and the infiltration of macrophages was denser in mice immunized with GL-GM combined with IFNgamma compared with that of both wildtype and nonimmunized mice. To our knowledge, this is the first study to demonstrate a synergy between GM-CSF and IFNgamma in experimental immunotherapy of tumors, by substantially increasing survival as well as inducing a potent anti-tumor response after only 1 postponed immunization.
authors.affiliation: Glioma Immunotherapy Group, Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, University of Lund, Sweden. karin.enell@med.lu.se
authors.forename: Karin E
authors.initials: KE
authors.lastname: Smith
authors.forename: Shorena
authors.initials: S
authors.lastname: Janelidze
authors.forename: Edward
authors.initials: E
authors.lastname: Visse
authors.forename: Wiaam
authors.initials: W
authors.lastname: Badn
authors.forename: Leif
authors.initials: L
authors.lastname: Salford
authors.forename: Peter
authors.initials: P
authors.lastname: Siesjö
authors.forename: Anna
authors.initials: A
authors.lastname: Darabi
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005805:Genes, MHC Class I / Q000502:physiology; D005802:Genes, MHC Class II / Q000502:physiology; D015316:Genetic Therapy; D005822:Genetic Vectors; D005910:Glioma / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000627:therapeutic use*; D007114:Immunization; D007124:Immunoenzyme Techniques; D007167:Immunotherapy; D007371:Interferon-gamma / Q000627:therapeutic use*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins; D015996:Survival Rate; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured / Q000528:radiation effects
chemical_list: D000998:Antiviral Agents; D011994:Recombinant Proteins; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor