Escape from the interferon response associated with RNA interference using vectors that encode long modified hairpin-RNA.
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.
Akashi
Hideo
H
Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo, Japan.
Miyagishi
Makoto
M
Yokota
Takanori
T
Watanabe
Tsunamasa
T
Hino
Taro
T
Nishina
Kazutaka
K
Kohara
Michinori
M
Taira
Kazunari
K
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
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