title: Molecular Basis for Antigenic Diversity of Genus Betanodavirus.
abstract: Betanodaviruses are the causative agents of viral nervous necrosis (VNN), a devastating disease for the Mediterranean mariculture. Four different betanodavirus species are recognized, Striped jack-, Redspotted grouper-, Tiger puffer-, and Barfin flounder nervous necrosis virus (SJNNV, RGNNV, TPNNV and BFNNV), but there is little knowledge on their antigenic properties. In order to describe the serological relationships among different betanodavirus genotypes, serum neutralization assays were performed using rabbit polyclonal antisera against eight fish nodaviruses that cover a wide species-, temporal-, spatial- and genetic range. The results indicate that the SJNNV and RGNNV are antigenically distinct, constituting serotypes A and C, respectively. The TPNNV and BFNNV, the latter representing cold-water betanodaviruses, are antigenically related and cluster within serotype B. The reassortant viruses RGNNV/SJNNV and SJNNV/RGNNV group within serotypes A and C, respectively, indicating that the coat protein encoded by RNA2 acts as major immunoreactivity determinant. Immunostaining of in vitro expressed wild type and chimeric capsid proteins between the RGNNV and the SJNNV species indicated that the C-terminal part of the capsid protein retains the immunoreactive portion. The amino acid (aa) residues determining RGNNV and SJNNV antigenic diversity were mapped to aa residues 217-256 and aa 257-341, respectively. Neutralization of reverse genetics derived chimeric viruses indicated that these areas determine the neutralizing epitopes. The data obtained are crucial for the development of targeted serological tests for the diagnosis of VNN, and informative for development of cross-protective vaccines against various betanodavirus genotypes.
authors.affiliation: OIE Reference Laboratory for Viral Encephalopathy and Retinopathy, Department of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy.|Department of Comparative Biomedicine and Food Science, University of Padua, Legnaro (PD), Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Panzarin
authors.affiliation: OIE Reference Laboratory for Viral Encephalopathy and Retinopathy, Department of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Toffan
authors.affiliation: OIE Reference Laboratory for Viral Encephalopathy and Retinopathy, Department of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy.
authors.forename: Miriam
authors.initials: M
authors.lastname: Abbadi
authors.affiliation: OIE Reference Laboratory for Viral Encephalopathy and Retinopathy, Department of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Buratin
authors.affiliation: OIE Reference Laboratory for Viral Encephalopathy and Retinopathy, Department of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy.
authors.forename: Marzia
authors.initials: M
authors.lastname: Mancin
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
authors.forename: Stine
authors.initials: S
authors.lastname: Braaen
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
authors.forename: Christel Moræus
authors.initials: CM
authors.lastname: Olsen
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padua, Legnaro (PD), Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bargelloni
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
authors.forename: Espen
authors.initials: E
authors.lastname: Rimstad
authors.affiliation: OIE Reference Laboratory for Viral Encephalopathy and Retinopathy, Department of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cattoli
mesh_terms: D000818:Animals; D000940:Antigenic Variation / Q000276:immunology*; D036022:Capsid Proteins / Q000378:metabolism; D002460:Cell Line; D016000:Cluster Analysis; D004847:Epithelial Cells / Q000378:metabolism / Q000821:virology; D005399:Fishes / Q000821:virology; D016624:Negative Staining; D009500:Neutralization Tests; D030381:Nodaviridae / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification / Q000648:ultrastructure; D010802:Phylogeny; D025341:Principal Component Analysis; D011994:Recombinant Proteins / Q000378:metabolism; D059386:Reverse Genetics; D012699:Serology; D018709:Statistics, Nonparametric
chemical_list: D036022:Capsid Proteins; D011994:Recombinant Proteins