title: In Vitro and in Vivo Evaluation of Mutations in the NS Region of Lineage 2 West Nile Virus Associated with Neuroinvasiveness in a Mammalian Model.
abstract: West Nile virus (WNV) strains may differ significantly in neuroinvasiveness in vertebrate hosts. In contrast to genetic lineage 1 WNVs, molecular determinants of pathogenic lineage 2 strains have not been experimentally confirmed so far. A full-length infectious clone of a neurovirulent WNV lineage 2 strain (578/10; Central Europe) was generated and amino acid substitutions that have been shown to attenuate lineage 1 WNVs were introduced into the nonstructural proteins (NS1 (P250L), NS2A (A30P), NS3 (P249H) NS4B (P38G, C102S, E249G)). The mouse neuroinvasive phenotype of each mutant virus was examined following intraperitoneal inoculation of C57BL/6 mice. Only the NS1-P250L mutation was associated with a significant attenuation of virulence in mice compared to the wild-type. Multiplication kinetics in cell culture revealed significantly lower infectious virus titres for the NS1 mutant compared to the wild-type, as well as significantly lower amounts of positive and negative stranded RNA.
authors.affiliation: Veterinary Diagnostic Directorate, National Food Chain Safety Office, H-1143, Budapest, Hungary. szgkati@gmail.com.
authors.forename: Katalin
authors.initials: K
authors.lastname: Szentpáli-Gavallér
authors.affiliation: Viroscience Laboratory, Erasmus Medical Centre, 3015CN, Rotterdam, The Netherlands. s.lim@erasmusmc.nl.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Lim
authors.affiliation: Veterinary Diagnostic Directorate, National Food Chain Safety Office, H-1143, Budapest, Hungary. balintad@nebih.gov.hu.
authors.forename: László
authors.initials: L
authors.lastname: Dencső
authors.affiliation: Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, H-1143, Budapest, Hungary. bkrota@hotmail.com.
authors.forename: Krisztián
authors.initials: K
authors.lastname: Bányai
authors.affiliation: Viroscience Laboratory, Erasmus Medical Centre, 3015CN, Rotterdam, The Netherlands. p.koraka@erasmusmc.nl.
authors.forename: Penelope
authors.initials: P
authors.lastname: Koraka
authors.affiliation: Viroscience Laboratory, Erasmus Medical Centre, 3015CN, Rotterdam, The Netherlands. a.osterhaus@erasmusmc.nl.
authors.forename: Albert D M E
authors.initials: AD
authors.lastname: Osterhaus
authors.affiliation: Viroscience Laboratory, Erasmus Medical Centre, 3015CN, Rotterdam, The Netherlands. b.martina@erasmusmc.nl.
authors.forename: Byron E E
authors.initials: BE
authors.lastname: Martina
authors.affiliation: Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science, Szent István University, H-1143, Budapest, Hungary. Bakonyi.Tamas@aotk.szie.hu.|Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine, A-1210, Vienna, Austria. Bakonyi.Tamas@aotk.szie.hu.
authors.forename: Tamás
authors.initials: T
authors.lastname: Bakonyi
authors.affiliation: Veterinary Diagnostic Directorate, National Food Chain Safety Office, H-1143, Budapest, Hungary. dencsol@nebih.gov.hu.
authors.forename: Ádám
authors.initials: Á
authors.lastname: Bálint
mesh_terms: D000818:Animals; D001921:Brain / Q000821:virology*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D009154:Mutation; D017361:Viral Nonstructural Proteins / Q000235:genetics* / Q000378:metabolism; D014774:Virulence; D014901:West Nile Fever / Q000821:virology*; D014902:West Nile virus / Q000145:classification / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*
chemical_list: D017361:Viral Nonstructural Proteins
keywords: West Nile virus; infectious clone; lineage 2; virulence markers