title: Expression of the murine norovirus (MNV) ORF1 polyprotein is sufficient to induce apoptosis in a virus-free cell model.
abstract: Investigations into human norovirus infection, replication and pathogenesis, as well as the development of potential antiviral agents, have been restricted by the lack of a cell culture system for human norovirus. To date, the optimal cell culture surrogate virus model for studying human norovirus biology is the murine norovirus (MNV). In this report we generate a tetracycline-regulated, inducible eukaryotic cell system expressing the entire MNV ORF1 polyprotein. Once induced, the MNV ORF1 polyprotein was faithfully processed to the six mature non-structural proteins that predominately located to a discrete perinuclear region, as has been observed in active MNV infection. Furthermore, we found that expression of the ORF1 polyprotein alone was sufficient to induce apoptosis, characterised by caspase-9 activation and survivin down-regulation. This cell line provides a valuable new tool for studying MNV ORF1 non-structural protein function, screening for potential antiviral agents and acts as a proof-of-principle for such systems to be developed for human noroviruses.
authors.affiliation: Molecular Microbiology Group, University of Southampton, Southampton, United Kingdom.
authors.forename: Morgan R
authors.initials: MR
authors.lastname: Herod
authors.affiliation: Molecular Microbiology Group, University of Southampton, Southampton, United Kingdom.
authors.forename: Omar
authors.initials: O
authors.lastname: Salim
authors.affiliation: Molecular Microbiology Group, University of Southampton, Southampton, United Kingdom.
authors.forename: Rachel J
authors.initials: RJ
authors.lastname: Skilton
authors.affiliation: Molecular Microbiology Group, University of Southampton, Southampton, United Kingdom.
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Prince
authors.affiliation: Otago School of Medical Sciences, Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
authors.forename: Vernon K
authors.initials: VK
authors.lastname: Ward
authors.affiliation: Molecular Microbiology Group, University of Southampton, Southampton, United Kingdom.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Lambden
authors.affiliation: Molecular Microbiology Group, University of Southampton, Southampton, United Kingdom.
authors.forename: Ian N
authors.initials: IN
authors.lastname: Clarke
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002999:Clone Cells; D016679:Genome, Viral / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008954:Models, Biological; D029322:Norovirus / Q000378:metabolism*; D020815:Polyproteins / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism; D013752:Tetracycline / Q000494:pharmacology; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D020815:Polyproteins; D012367:RNA, Viral; D014764:Viral Proteins; D013752:Tetracycline