title: The role of capsid-endothelial interactions in the innate immune response to adenovirus vectors.
abstract: Adenovirus (Ad) vectors can produce inflammatory responses at high doses. Intravenous administration of an Ad vector expressing green fluorescent protein (AdGFP) to naive mice induced a biphasic pattern of liver cytokine/chemokine gene expression over 7 days. Tumor necrosis factor alpha (TNF-alpha), macrophage inflammatory protein 2 (MIP-2), and interferon gamma-inducible protein 10 (IP-10) genes were upregulated, with two distinct peaks of mRNA expression occurring at 6 hr and 5 days. The administration of transcription-defective AdGFP particles induced the early but not the late peak of chemokine/cytokine gene expression, confirming that Ad vector-induced inflammation is capsid dependent in the early phase and transcription dependent in the late phase. To determine the role of adenoviral capsid motifs in the early phase, capsid-modified Ad vectors were employed. The intravenous administration of the RGD-deleted Ad vector AdL.PB*, the fiber mutant AdL.F*, or the double mutant AdL.F*PB* induced similar levels of cytokine/chemokine expression compared with the wild-type vector AdLuc. Kupffer cell blockade significantly reduced liver TNF-alpha, MIP-2, and IP-10 gene expression and liver inflammation after the administration of AdL.PB* or AdL.F*PB*. Fluorescence microscopy of AdLuc- and AdL.PB*-transduced liver at 1 hr revealed localization of Ad vectors to liver sinusoids in Kupffer cell-depleted mice. AdL.PB* induced less E-selectin and VCAM-1 gene expression in liver, confirming reduced endothelial activation in mice receiving RGD-deleted Ad vectors. In vitro studies of endothelial cells demonstrated reduced transduction and endothelial activation by AdL.PB* compared with AdLuc. These results demonstrate that adenovirus capsid RGD motifs are required for efficient transduction and endothelial cell activation. Altering vector tropism represents a feasible strategy to modulate the innate response to Ad vectors in nontargeted tissues.
authors.affiliation: Department of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.forename: Anne K
authors.initials: AK
authors.lastname: Zaiss
authors.forename: Pina
authors.initials: P
authors.lastname: Colarusso
authors.forename: Kamala
authors.initials: K
authors.lastname: Patel
authors.forename: Gregory
authors.initials: G
authors.lastname: Haljan
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Wickham
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Muruve
mesh_terms: D000256:Adenoviridae / Q000235:genetics* / Q000276:immunology*; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D002213:Capsid / Q000276:immunology / Q000378:metabolism; D002465:Cell Movement; D018925:Chemokines / Q000096:biosynthesis; D016207:Cytokines / Q000096:biosynthesis; D003673:Defective Viruses / Q000235:genetics; D004730:Endothelium, Vascular / Q000378:metabolism; D005822:Genetic Vectors / Q000032:analysis / Q000276:immunology* / Q000633:toxicity; D006801:Humans; D007728:Kupffer Cells / Q000276:immunology; D008099:Liver / Q000033:anatomy & histology / Q000276:immunology* / Q000821:virology; D051379:Mice; D008811:Mice, Inbred DBA; D009504:Neutrophils / Q000276:immunology; D009842:Oligopeptides / Q000235:genetics; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014158:Transcription, Genetic; D014161:Transduction, Genetic
chemical_list: D018925:Chemokines; D016207:Cytokines; D009842:Oligopeptides; C047981:arginyl-glycyl-aspartic acid; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase