title: Establishment of a reverse genetics system for Schmallenberg virus, a newly emerged orthobunyavirus in Europe.
abstract: Schmallenberg virus (SBV) is a newly emerged orthobunyavirus that has caused widespread disease in cattle, sheep and goats in Europe. Like other orthobunyaviruses, SBV is characterized by a tripartite negative-sense RNA genome that encodes four structural and two non-structural proteins. This study showed that SBV has a wide in vitro host range, and that BHK-21 cells are a convenient host for both SBV propagation and assay by plaque titration. The SBV genome segments were cloned as cDNA and a three-plasmid rescue system was established to recover infectious virus. Recombinant virus behaved similarly in cell culture to authentic virus. The ORF for the non-structural NSs protein, encoded on the smallest genome segment, was disrupted by introduction of translation stop codons in the appropriate cDNA, and when this plasmid was used in reverse genetics, a recombinant virus that lacked NSs expression was recovered. This virus had reduced capacity to shut-off host-cell protein synthesis compared with the wild-type virus. In addition, the NSs-deleted virus induced interferon (IFN) in cells, indicating that, like other orthobunyaviruses, NSs functions as an IFN antagonist, most probably by globally inhibiting host-cell metabolism. The development of a robust reverse genetics system for SBV will facilitate investigation of its pathogenic mechanisms as well as the creation of attenuated strains that could be candidate vaccines.
authors.affiliation: Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, KY16 9ST, Scotland, UK.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Elliott
authors.affiliation: Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, KY16 9ST, Scotland, UK.
authors.forename: Gjon
authors.initials: G
authors.lastname: Blakqori
authors.affiliation: Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, KY16 9ST, Scotland, UK.
authors.forename: Ingeborg C
authors.initials: IC
authors.lastname: van Knippenberg
authors.affiliation: Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, KY16 9ST, Scotland, UK.
authors.forename: Elina
authors.initials: E
authors.lastname: Koudriakova
authors.affiliation: Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, KY16 9ST, Scotland, UK.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, KY16 9ST, Scotland, UK.
authors.forename: Angela
authors.initials: A
authors.lastname: McLees
authors.affiliation: Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, KY16 9ST, Scotland, UK.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Shi
authors.affiliation: Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, KY16 9ST, Scotland, UK.
authors.forename: Agnieszka M
authors.initials: AM
authors.lastname: Szemiel
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D058507:Host Specificity; D016851:Orthobunyavirus / Q000235:genetics* / Q000502:physiology; D010957:Plasmids; D059386:Reverse Genetics / Q000379:methods*; D010948:Viral Plaque Assay; D014773:Virology / Q000379:methods*; D014776:Virus Cultivation