title: The antiviral defense mechanisms in mandarin fish induced by DNA vaccination against a rhabdovirus.
abstract: Plasmid DNAs containing Siniperca chuatsi rhabdovirus (SCRV) glycoprotein gene (pcDNA-G) and nucleoprotein gene (pcDNA-N) were constructed, and used to determine the antiviral immune response elicited by DNA vaccination in mandarin fish. In vitro and in vivo expression of the plasmid constructs was confirmed in transfected cells and muscle tissues of vaccinated fish by Western blot, indirect immunofluorescence or RT-PCR analysis. Fish injected with pcDNA-G exhibited protective effect against SCRV challenge with a relative percent survival (RPS) of 77.5%, but no significant protection (RPS of 2.5%) was observed in fish vaccinated with pcDNA-N. Immunohistochemical analysis showed that vaccination with pcDNA-G decreased histological lesions and suppressed the virus replication in fish target organs, e.g. kidney, liver, spleen, gill and heart. Transcriptional analysis further revealed that the expression levels of type I IFN system genes including interferon regulation factor-7 (IRF-7) gene, myxovirus resistance (Mx) gene and virus inhibitory protein (Viperin) gene were strongly up-regulated after injection with pcDNA-G, whereas the level of transcription of immunoglobulin M (IgM) gene did not show a statistically significant change. These results reveal that type I IFN antiviral immune response is rapidly triggered by the plasmid DNA containing rhabdovirus glycoprotein gene in fish, which offers an explanation of molecular mechanisms for DNA vaccination inducing mandarin fish resist to SCRV disease.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Zhong-Yuan
authors.initials: ZY
authors.lastname: Chen
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Lei
authors.forename: Qi-Ya
authors.initials: QY
authors.lastname: Zhang
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D005393:Fish Diseases / Q000276:immunology / Q000517:prevention & control*; D019204:GTP-Binding Proteins / Q000276:immunology; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D050839:Interferon Regulatory Factor-7 / Q000276:immunology; D007370:Interferon Type I / Q000276:immunology; D064547:Myxovirus Resistance Proteins; D010473:Perciformes / Q000276:immunology* / Q000821:virology; D010957:Plasmids; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012209:Rhabdoviridae / Q000472:pathogenicity*; D018353:Rhabdoviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D014611:Vaccination / Q000662:veterinary; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000235:genetics / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D006023:Glycoproteins; D007075:Immunoglobulin M; D050839:Interferon Regulatory Factor-7; D007370:Interferon Type I; D064547:Myxovirus Resistance Proteins; D019444:Vaccines, DNA; D014764:Viral Proteins; D014765:Viral Vaccines; D019204:GTP-Binding Proteins