Mutations in the envelope protein of Japanese encephalitis virus affect entry into cultured cells and virulence in mice

Virology. 1992 Nov;191(1):158-65. doi: 10.1016/0042-6822(92)90177-q.


The nucleotide sequences of the envelope protein of the Kamiyama 1 strain of Japanese encephalitis (JE) virus and a passaged mutant (Kamiyama 2 strain) were determined. Two amino acid differences, Ser-Phe at residue 364 and Asn-Ile at residue 367, distinguished Kamiyama 2 from Kamiyama 1. Six neutralization-resistant variants were selected from these two strains using a JE species-specific monoclonal antibody with neutralization and hemagglutination-inhibition reactivities. All variants had a single amino acid substitution at residue 52 and significantly reduced reactivity with other JE species-specific monoclonal antibodies. The variants derived from Kamiyama 2 strain showed reduced virulence in 3-week-old mice after peripheral inoculation but were as virulent as the parent virus when inoculated intracranially. These variants also showed altered early virus-cell interaction but not replication and reproduction in Vero cells. These findings indicate that the mutations at residues 52, 364, and 367 affect early virus-cell interaction in Vero cells and virulence in mice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal
  • Base Sequence
  • Cells, Cultured
  • Encephalitis Virus, Japanese / genetics*
  • Encephalitis Virus, Japanese / pathogenicity
  • Encephalitis Virus, Japanese / physiology
  • Encephalitis, Japanese / microbiology*
  • Mice
  • Mice, Inbred BALB C
  • Molecular Sequence Data
  • Mutation
  • Neutralization Tests
  • RNA, Viral
  • Vero Cells
  • Viral Envelope Proteins / genetics*
  • Virulence / genetics
  • Virus Replication


  • Antibodies, Monoclonal
  • RNA, Viral
  • Viral Envelope Proteins