title: A high throughput in vivo model for testing delivery and antiviral effects of siRNAs in vertebrates.
abstract: Despite the promise of small interfering RNAs (siRNAs) in antiviral therapy, few in vivostudies of them as inhibitors of viral replication and disease have been published, a lack that is most probably due to problems with obtaining successful delivery. Here we introduce a novel in vivomodel composed of small juvenile rainbow trout and a fish pathogenic virus to analyze the delivery and antiviral effects of formulated siRNAs. Intraperitoneally (IP) injected siRNAs formulated in polycationic liposomes, and to a lesser degree naked siRNAs, primarily entered free IP cells, including macrophage-like cells. Uptake in these cells correlated with antiviral activity, seen as reduced mortality of virus-challenged fish. However, protection at the disease level was not dependent upon which of three tested siRNAs was used, and protection correlated with up-regulation of an interferon (IFN)-related gene in the liver, indicating a systemic IFN response. The results emphasize the compromise in using transfection reagents for improved uptake of siRNAs, where these reagents also increase the risk of the siRNAs ending up in a cellular compartment in which stimulation of non-specific anti-viral defence mechanisms will be initiated.
authors.affiliation: National Veterinary Institute, Technical University of Denmark, Arhus N., Denmark. bds@vet.dtu.dk
authors.forename: Brian Dall
authors.initials: BD
authors.lastname: Schyth
authors.forename: Niels
authors.initials: N
authors.lastname: Lorenzen
authors.forename: Finn Skou
authors.initials: FS
authors.lastname: Pedersen
mesh_terms: D000818:Animals; D005229:Fatty Acids, Monounsaturated; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D007372:Interferons / Q000494:pharmacology; D007668:Kidney / Q000196:embryology / Q000378:metabolism; D008957:Models, Genetic; D017686:Oncorhynchus mykiss / Q000235:genetics / Q000378:metabolism; D011070:Poly I-C / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds; D034741:RNA, Small Interfering / Q000235:genetics*; D019076:Transgenes / Q000235:genetics*
chemical_list: D005229:Fatty Acids, Monounsaturated; D000644:Quaternary Ammonium Compounds; D034741:RNA, Small Interfering; D007372:Interferons; C070046:1,2-dioleoyloxy-3-(trimethylammonium)propane; D011070:Poly I-C