Multiple amino acid variations in the nonstructural proteins of swine Japanese encephalitis virus alter its virulence in mice

• Published in: Archives of virology 2011-04, Vol.156 (4), p.685-688
• Main Authors: Wu, Rui, Tian, Yongxiang, Deng, Junhua, Yang, Keli, Liang, Wangwang, Guo, Rui, Duan, Zhengying, Liu, Zewen, Zhou, Danna, Xu, Diping
• Format: Article
• Language: English
• Subjects: Adaptation, Biological; Amino acids; Animals; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Body Weight; Brief Report; DNA Mutational Analysis; Encephalitis; Encephalitis Virus, Japanese - genetics; Encephalitis Virus, Japanese - isolation & purification; Encephalitis Virus, Japanese - pathogenicity; Encephalitis, Japanese - veterinary; Encephalitis, Japanese - virology; Fundamental and applied biological sciences. Psychology; Genomes; Hogs; Infections; Infectious Diseases; Japanese encephalitis virus; Medical Microbiology; Mice; Mice, Inbred BALB C; Microbiology; Miscellaneous; Mutation, Missense; Proteins; RNA, Viral - genetics; Serial Passage; Survival Analysis; Swine; Swine Diseases - virology; Viral Nonstructural Proteins - genetics; Virology; Virulence; Viruses
• ISSN: 0304-8608; 1432-8798
• DOI: 10.1007/s00705-010-0871-1

In a previous study, we performed serial brain-to-brain passages of swine Japanese encephalitis virus in mice and sequenced the complete genomes of the F5 and F20 passaged mouse-adapted variants. In the current study, we analyzed the differences between their genome sequences and found 12 amino acid substitutions in the nonstructural proteins. We also assessed the growth characteristics of these two variants in mammalian cells in vitro and in vivo . Our investigations revealed that the F20 variant had enhanced growth characteristics and modified virulence compared with the F5 variant. We therefore conclude that multiple amino acid substitutions in the nonstructural proteins of swine Japanese encephalitis virus alter its virulence in mice.