title: Cell-to-cell spread of the RNA interference response suppresses Semliki Forest virus (SFV) infection of mosquito cell cultures and cannot be antagonized by SFV.
abstract: In their vertebrate hosts, arboviruses such as Semliki Forest virus (SFV) (Togaviridae) generally counteract innate defenses and trigger cell death. In contrast, in mosquito cells, following an early phase of efficient virus production, a persistent infection with low levels of virus production is established. Whether arboviruses counteract RNA interference (RNAi), which provides an important antiviral defense system in mosquitoes, is an important question. Here we show that in Aedes albopictus-derived mosquito cells, SFV cannot prevent the establishment of an antiviral RNAi response or prevent the spread of protective antiviral double-stranded RNA/small interfering RNA (siRNA) from cell to cell, which can inhibit the replication of incoming virus. The expression of tombusvirus siRNA-binding protein p19 by SFV strongly enhanced virus spread between cultured cells rather than virus replication in initially infected cells. Our results indicate that the spread of the RNAi signal contributes to limiting virus dissemination.
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Summerhall, Edinburgh, Scotland, United Kingdom.
authors.forename: Ghassem
authors.initials: G
authors.lastname: Attarzadeh-Yazdi
authors.forename: Rennos
authors.initials: R
authors.lastname: Fragkoudis
authors.forename: Yi
authors.initials: Y
authors.lastname: Chi
authors.forename: Ricky W C
authors.initials: RW
authors.lastname: Siu
authors.forename: Liane
authors.initials: L
authors.lastname: Ulper
authors.forename: Gerald
authors.initials: G
authors.lastname: Barry
authors.forename: Julio
authors.initials: J
authors.lastname: Rodriguez-Andres
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Nash
authors.forename: Michèle
authors.initials: M
authors.lastname: Bouloy
authors.forename: Andres
authors.initials: A
authors.lastname: Merits
authors.forename: John K
authors.initials: JK
authors.lastname: Fazakerley
authors.forename: Alain
authors.initials: A
authors.lastname: Kohl
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D009033:Culicidae / Q000821:virology*; D015967:Gene Expression Regulation, Viral; D034622:RNA Interference; D012367:RNA, Viral / Q000235:genetics; D012672:Semliki forest virus / Q000235:genetics*; D014779:Virus Replication
chemical_list: D012367:RNA, Viral