title: Enhancement of pathogenicity of Newcastle disease virus by alteration of specific amino acid residues in the surface glycoproteins F and HN.
abstract: Recombinant viruses were rescued after site-specific mutagenesis of a full-length clone of the lentogenic Newcastle disease virus (NDV) strain Clone 30. To assess the contribution of different amino acids to virulence, specific alterations were introduced into the fusion (F) protein and in the hemagglutinin-neuraminidase (HN) protein based on sequence comparison between NDV strains of different virulence. Modification of the proteolytic cleavage site in the F protein to a polybasic motif increased the intracerebral pathogenicity index (ICPI) from 0.0 to 1.28. Moreover, the additional exchange of amino acid 123 of the HN protein from tryptophan to cysteine in combination with alteration of amino acid 27 of the F protein from cysteine to arginine increased the ICPI to 1.5. The HN mutation visibly altered conformation of the protein, resulting in the formation of disulfide-linked HN dimers that may indicate that this HN conformation is beneficial for the virulent phenotype.
authors.affiliation: Institute of Molecular Biology, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany.
authors.forename: Angela
authors.initials: A
authors.lastname: Römer-Oberdörfer
authors.forename: Jutta
authors.initials: J
authors.lastname: Veits
authors.forename: Ortrud
authors.initials: O
authors.lastname: Werner
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Mettenleiter
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics*; D000818:Animals; D002460:Cell Line; D002642:Chick Embryo; D018076:DNA, Complementary / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D009522:Newcastle disease virus / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D011784:Quail; D014759:Viral Envelope Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014774:Virulence / Q000235:genetics; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
chemical_list: D018076:DNA, Complementary; D014759:Viral Envelope Proteins