title: Assessment of a combined, adenovirus-mediated oncolytic and immunostimulatory tumor therapy.
abstract: In this study, we identified murine breast cancer cell lines that support DNA replication of E1-deleted adenovirus vectors and which can be killed by an oncolytic adenovirus expressing adenovirus E1A and tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL) in a replication-dependent manner (Ad.IR-E1A/TRAIL). We showed that systemic or intratumoral (i.t.) injection of adenovirus vectors into mice increases plasma levels of proinflammatory cytokines and chemokines, including TNF-alpha, INF-gamma, and MCP-1, which are potent inducers of dendritic cell maturation. Furthermore, we showed that in vivo expression of Flt3L from an adenovirus vector increases the number of CD11b+ and CD11c+ cells (populations that include dendritic cells) in the blood circulation. Based on these findings, we tested whether Ad.IR-E1A/TRAIL induced killing of tumor cells in combination with dendritic cell mobilization by Ad.Flt3L or, for comparison, Ad.GM-CSF would have an additive antitumor effect. As a model, we used immunocompetent C3H mice with syngeneic s.c. tumors derived from C3L5 cells. We found that vaccination of mice with C3L5 cells that underwent viral oncolysis in combination with Flt3L or granulocyte-macrophage colony-stimulating factor (GM-CSF) expression induces a systemic antitumor immune response. I.t. injection of the oncolytic and Flt3L expressing vectors into established tumors delayed tumor growth but did not cause efficient tumor elimination. This study shows the effectiveness of a combined oncolytic/immunostimulatory tumor therapy approach.
authors.affiliation: Division of Medical Genetics and Department of Pathology, University of Washington, Seattle, Washington, USA.
authors.forename: Kathrin Maria
authors.initials: KM
authors.lastname: Bernt
authors.forename: Shaoheng
authors.initials: S
authors.lastname: Ni
authors.forename: Anh-Thu
authors.initials: AT
authors.lastname: Tieu
authors.forename: André
authors.initials: A
authors.lastname: Lieber
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D017500:Adenovirus E1A Proteins / Q000096:biosynthesis / Q000235:genetics; D000818:Animals; D051017:Apoptosis Regulatory Proteins; D039481:CD11b Antigen / Q000276:immunology / Q000378:metabolism; D039521:CD11c Antigen / Q000276:immunology / Q000378:metabolism; D019496:Cancer Vaccines / Q000235:genetics / Q000276:immunology*; D004261:DNA Replication; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D008325:Mammary Neoplasms, Experimental / Q000276:immunology / Q000628:therapy* / Q000821:virology; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics
chemical_list: D017500:Adenovirus E1A Proteins; D051017:Apoptosis Regulatory Proteins; D039481:CD11b Antigen; D039521:CD11c Antigen; D019496:Cancer Vaccines; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; C505654:Tnfsf10 protein, mouse; D014409:Tumor Necrosis Factor-alpha; C084881:flt3 ligand protein; D016178:Granulocyte-Macrophage Colony-Stimulating Factor