title: Oyster viperin retains direct antiviral activity and  its transcription occurs via a signalling pathway  involving a heat-stable haemolymph protein.
abstract: Little is known about the response of non-model invertebrates, such as oysters, to virus infection. The vertebrate innate immune system detects virus-derived nucleic acids to trigger the type I IFN pathway, leading to the transcription of hundreds of IFN-stimulated genes (ISGs) that exert antiviral functions. Invertebrates were thought to lack the IFN pathway based on the absence of IFN or ISGs encoded in model invertebrate genomes. However, the oyster genome encodes many ISGs, including the well-described antiviral protein viperin. In this study, we characterized oyster viperin and showed that it localizes to caveolin-1 and inhibits dengue virus replication in a heterologous model. In a second set of experiments, we have provided evidence that the haemolymph from poly(I : C)-injected oysters contains a heat-stable, protease-susceptible factor that induces haemocyte transcription of viperin mRNA in conjunction with upregulation of IFN regulatory factor. Collectively, these results support the concept that oysters have antiviral systems that are homologous to the vertebrate IFN pathway.
authors.affiliation: School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia.|Department of Biological Sciences and Sydney Institute of Marine Science, Macquarie University, NSW 2109, Australia.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Green
authors.affiliation: School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Speck
authors.affiliation: School of Biological Sciences, University of Adelaide, SA 5001, Australia.
authors.forename: Lu
authors.initials: L
authors.lastname: Geng
authors.affiliation: Department of Biological Sciences and Sydney Institute of Marine Science, Macquarie University, NSW 2109, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Raftos
authors.affiliation: School of Biological Sciences, University of Adelaide, SA 5001, Australia.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Beard
authors.affiliation: School of Biological Sciences, University of Adelaide, SA 5001, Australia.
authors.forename: Karla J
authors.initials: KJ
authors.lastname: Helbig
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism; D003716:Dengue Virus / Q000187:drug effects; D005786:Gene Expression Regulation / Q000502:physiology; D006458:Hemolymph / Q000737:chemistry*; D006358:Hot Temperature; D008055:Lipids / Q000737:chemistry; D008969:Molecular Sequence Data; D010125:Ostreidae / Q000378:metabolism* / Q000821:virology*; D011506:Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D015398:Signal Transduction / Q000502:physiology*; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D051242:Caveolin 1; D008055:Lipids; D011506:Proteins