title: A TLR and non-TLR mediated innate response to lentiviruses restricts hepatocyte entry and can be ameliorated by pharmacological blockade.
abstract: Lentiviral vector (LV)-mediated gene transfer is a promising method of gene therapy. We previously reported that systemic injection of HIV-based LV triggers a transient inflammatory response. Here, we carried out studies to better characterize this response, and to develop a strategy to overcome the adverse effects of interferon (IFN) on LV-mediated gene transfer. We profiled gene expression in the liver after LV administration using deep-sequencing (RNA-seq), and identified several innate response pathways. We examined the response to LV in MyD88-TRIF knockout mice, which are incapable of toll-like receptor (TLR) signaling. Unexpectedly, the IFN response to LV was not reduced in the liver indicating that a non-TLR pathway can recognize LV in this organ. Indeed, blocking reverse transcription with azidothymidine (AZT) reduced the IFN response only in the liver, suggesting that proviral DNA can be a trigger. To block the inflammatory response, we pretreated mice with a short course of dexamethasone (Dex). At 4 hours post-treatment, all the IFN-induced genes were normalized. By blocking the inflammatory response, hepatocyte transduction was dramatically increased, which in turn doubled the level of human factor IX (FIX) produced by a hepatocyte-specific LV. Our studies uncover new insights into LV-induced immune responses in the liver, and provide a means to increase the safety and efficiency of LV-mediated gene transfer.
authors.affiliation: Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York City, NY 10028, USA.
authors.forename: Judith
authors.initials: J
authors.lastname: Agudo
authors.forename: Albert
authors.initials: A
authors.lastname: Ruzo
authors.forename: Kipyegon
authors.initials: K
authors.lastname: Kitur
authors.forename: Ravi
authors.initials: R
authors.lastname: Sachidanandam
authors.forename: J Magarian
authors.initials: JM
authors.lastname: Blander
authors.forename: Brian D
authors.initials: BD
authors.lastname: Brown
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D005434:Flow Cytometry; D022781:Hepatocytes / Q000378:metabolism*; D007113:Immunity, Innate / Q000235:genetics / Q000502:physiology; D007150:Immunohistochemistry; D016086:Lentivirus / Q000235:genetics / Q000276:immunology*; D008099:Liver / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics / Q000378:metabolism; D051193:Toll-Like Receptors / Q000235:genetics / Q000378:metabolism*
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D053594:Myeloid Differentiation Factor 88; D051193:Toll-Like Receptors; C476286:Ticam1 protein, mouse