title: RNA interference functions as an antiviral immunity mechanism in mammals.
abstract: Diverse eukaryotic hosts produce virus-derived small interfering RNAs (siRNAs) to direct antiviral immunity by RNA interference (RNAi). However, it remains unknown whether the mammalian RNAi pathway has a natural antiviral function. Here, we show that infection of hamster cells and suckling mice by Nodamura virus (NoV), a mosquito-transmissible RNA virus, requires RNAi suppression by its B2 protein. Loss of B2 expression or its suppressor activity leads to abundant production of viral siRNAs and rapid clearance of the mutant viruses in mice. However, viral small RNAs detected during virulent infection by NoV do not have the properties of canonical siRNAs. These findings have parallels with the induction and suppression of antiviral RNAi by the related Flock house virus in fruit flies and nematodes and reveal a mammalian antiviral immunity mechanism mediated by RNAi.
authors.affiliation: Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Lu
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Han
authors.forename: Xiaoxu
authors.initials: X
authors.lastname: Fan
authors.forename: Shou-Wei
authors.initials: SW
authors.lastname: Ding
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D051379:Mice; D030381:Nodaviridae / Q000235:genetics / Q000472:pathogenicity*; D034622:RNA Interference / Q000276:immunology*; D012327:RNA Virus Infections / Q000276:immunology*; D034741:RNA, Small Interfering / Q000276:immunology*; D012367:RNA, Viral / Q000235:genetics / Q000276:immunology*; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D034741:RNA, Small Interfering; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins