title: Escape from the interferon response associated with RNA interference using vectors that encode long modified hairpin-RNA.
abstract: In mammalian cells, siRNAs have been used to induce RNA interference (RNAi) in an attempt to prevent nonspecific effects (including the interferon (IFN) response) which are caused by long double-stranded RNAs (dsRNAs) of more than 30 bp. In this report, we describe a novel and simple strategy for avoiding activation of the IFN response by dsRNA. We show that modified hairpin-RNAs (mhRNAs) of more than 100 bp, with multiple specific point-mutations within the sense strand and transcribed from the U6 or tRNA(Val) promoters, can cause RNAi without inducing the IFN pathway genes. Moreover, we demonstrate that the 50-bp mhRNA vector could effectively suppress the replication of multiple hepatitis C viruses (the genomes of which differ slightly, thus the 21-bp siRNA vector failed to suppress one of them). Our findings should enhance the exploitation of RNAi in mammalian cells, especially in the field of RNAi therapy against pathogenic viruses.
authors.affiliation: Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Akashi
authors.forename: Makoto
authors.initials: M
authors.lastname: Miyagishi
authors.forename: Takanori
authors.initials: T
authors.lastname: Yokota
authors.forename: Tsunamasa
authors.initials: T
authors.lastname: Watanabe
authors.forename: Taro
authors.initials: T
authors.lastname: Hino
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Nishina
authors.forename: Michinori
authors.initials: M
authors.lastname: Kohara
authors.forename: Kazunari
authors.initials: K
authors.lastname: Taira
mesh_terms: D001483:Base Sequence; D005822:Genetic Vectors; D006367:HeLa Cells; D016174:Hepacivirus / Q000235:genetics / Q000502:physiology*; D006801:Humans; D007372:Interferons / Q000378:metabolism*; D008969:Molecular Sequence Data; D012313:RNA; D034622:RNA Interference; D012319:RNA Polymerase II; D034741:RNA, Small Interfering; D012342:RNA, Small Nuclear; D012343:RNA, Transfer; D014162:Transfection; D014779:Virus Replication
chemical_list: D034741:RNA, Small Interfering; D012342:RNA, Small Nuclear; C405486:U6 small nuclear RNA; D012313:RNA; D007372:Interferons; D012343:RNA, Transfer; D012319:RNA Polymerase II; C410949:RNA polymerase II largest subunit