title: [Phylogenetic analysis and pathogenicity of tick-borne encephalitis virus from Japan and far-east Russia].
abstract: Phylogenetic analysis of tick-borne encephalitis (TBE) virus revealed that Hokkaido strain of TBE virus evolved several hundreds years ago in far-east Russia. TBE virus strains in Irkutsk area were identified as Siberian subtype of TBE virus. BHK-cell adapted mutant of TBE virus showed lower neuro-invasive virulence in mice than parent virus. The mutant carried one amino acid substitution in envelope protein which resulted in increase of positive charge of the protein. The mutant-infected mice showed lower virus titers in bloods and spleens than the parent-infected mice. Infectious c-DNA clone of TBE virus Hokkaido strain was successfully generated and was applied to examine the neurovirulence in mice. One amino acid change in envelope protein and 2 amino acid changes in Ns5 protein showed a synergistic effect on reduced neurovirulence in mice.
authors.affiliation: Laboratory of Public Health, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Takashima
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hayasaka
authors.forename: Akiko
authors.initials: A
authors.lastname: Goto
authors.forename: Kentarou
authors.initials: K
authors.lastname: Yoshii
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kariwa
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D003001:Cloning, Molecular; D006224:Cricetinae; D004279:DNA, Viral; D004669:Encephalitis Viruses, Tick-Borne / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D004675:Encephalitis, Tick-Borne / Q000821:virology*; D006801:Humans; D007564:Japan; D051379:Mice; D009154:Mutation; D010802:Phylogeny; D012426:Russia; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics; D014774:Virulence / Q000235:genetics
chemical_list: D004279:DNA, Viral; D014759:Viral Envelope Proteins