Bispidine-Amino Acid Conjugates Act as a Novel Scaffold for the Design of Antivirals That Block Japanese Encephalitis Virus Replication

The phenotypic and genotypic characteristics of a live-attenuated genotype I (GI) strain (SD12-F120) of Japanese encephalitis virus (JEV) were compared with its virulent parental SD12 strain to gain an insight into the genetic changes acquired during the attenuation process. SD12-F120 formed smaller plaque on BHK-21 cells and showed reduced replication in mouse brains compared with SD12. Mice inoculated with SD12-F120 via either intraperitoneal or intracerebral route showed no clinical symptoms, indicating a highly attenuated phenotype in terms of both neuroinvasiveness and neurovirulence. SD12-F120 harbored 29 nucleotide variations compared with SD12, of which 20 were considered silent nucleotide mutations, while nine resulted in eight amino acid substitutions. Comparison of the amino acid variations of SD12-F120 vs. SD12 pair with those from other four isogenic pairs of the attenuated and their virulent parental strains revealed that the variations at E138 and E176 positions of E protein were identified in four and three pairs, respectively, while the remaining amino acid variations were almost unique to their respective strain pairs. These observations suggest that the genetic changes acquired during the attenuation process were likely to be strain-specific and that the mechanisms associated with JEV attenuation/virulence are complicated.

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Amino Acid at Position 166 of NS2A in Japanese Encephalitis Virus (JEV) Is Associated with In Vitro Growth Characteristics of JEV

Viruses ◽

10.3390/v12070709 ◽

2020 ◽

Vol 12 (7) ◽

pp. 709

Author(s):

Shigeru Tajima ◽

Satoshi Taniguchi ◽

Eri Nakayama ◽

Takahiro Maeki ◽

Takuya Inagaki ◽

...

Keyword(s):

Amino Acid ◽

Japanese Encephalitis Virus ◽

Japanese Encephalitis ◽

Neuroblastoma Cells ◽

Encephalitis Virus ◽

Growth Potential ◽

Sequencing Analysis ◽

Murine Neuroblastoma ◽

Growth Ability

We previously showed that the growth ability of the Japanese encephalitis virus (JEV) genotype V (GV) strain Muar is clearly lower than that of the genotype I (GI) JEV strain Mie/41/2002 in murine neuroblastoma cells. Here, we sought to identify the region in GV JEV that is involved in its low growth potential in cultured cells. An intertypic virus containing the NS1-3 region of Muar in the Mie/41/2002 backbone (NS1-3Muar) exhibited a markedly diminished growth ability in murine neuroblastoma cells. Moreover, the growth rate of a Muar NS2A-bearing intertypic virus (NS2AMuar) was also similar to that of Muar in these cells, indicating that NS2A of Muar is one of the regions responsible for the Muar-specific growth ability in murine neuroblastoma cells. Sequencing analysis of murine neuroblastoma Neuro-2a cell-adapted NS1-3Muar virus clones revealed that His-to-Tyr mutation at position 166 of NS2A (NS2A166) could rescue the low replication ability of NS1-3Muar in Neuro-2a cells. Notably, a virus harboring a Tyr-to-His substitution at NS2A166 (NS2AY166H) showed a decreased growth ability relative to that of the parental virus Mie/41/2002, whereas an NS2AMuar-based mutant virus, NS2AMuar-H166Y, showed a higher growth ability than NS2AMuar in Neuro-2a cells. Thus, these results indicate that the NS2A166 amino acid in JEV is critical for the growth and tissue tropism of JEV in vitro.

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Comparison of genomic and amino acid sequences of eight Japanese encephalitis virus isolates from bats

Archives of Virology ◽

10.1007/s00705-013-1777-5 ◽

2013 ◽

Vol 158 (12) ◽

pp. 2543-2552 ◽

Cited By ~ 15

Author(s):

Shan Liu ◽

Xing Li ◽

Zhiyong Chen ◽

Yixiong Chen ◽

Qionghua Zhang ◽

...

Keyword(s):

Amino Acid ◽

Japanese Encephalitis Virus ◽

Japanese Encephalitis ◽

Amino Acid Sequences ◽

Encephalitis Virus ◽

Virus Isolates

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A Simple Mechanism Based on Amino Acid Substitutions is not a Critical Determinant of High Mortality of Japanese Encephalitis Virus Infection in Mice

Viruses ◽

10.3390/v10020062 ◽

2018 ◽

Vol 10 (2) ◽

pp. 62

Author(s):

Yuki Takamatsu ◽

Leo Uchida ◽

Muhareva Raekiansyah ◽

Mark Luz ◽

Kouichi Morita ◽

...

Keyword(s):

Amino Acid ◽

Virus Infection ◽

Japanese Encephalitis Virus ◽

Japanese Encephalitis ◽

High Mortality ◽

Encephalitis Virus ◽

Amino Acid Substitutions ◽

Critical Determinant ◽

Japanese Encephalitis Virus Infection ◽

Simple Mechanism

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A Single Amino Acid Substitution in the NS2A Protein of Japanese Encephalitis Virus Affects Virus PropagationIn Vitrobut NotIn Vivo

Journal of Virology ◽

10.1128/jvi.00370-15 ◽

2015 ◽

Vol 89 (11) ◽

pp. 6126-6130 ◽

Cited By ~ 4

Author(s):

Yuki Takamatsu ◽

Kouichi Morita ◽

Daisuke Hayasaka

Keyword(s):

Amino Acid ◽

Japanese Encephalitis Virus ◽

Japanese Encephalitis ◽

Encephalitis Virus ◽

Single Amino Acid ◽

Virus Propagation ◽

Viral Loads ◽

Unique Amino Acid

We identified a unique amino acid of NS2A113, phenylalanine, that affects the efficient propagation of two Japanese encephalitis virus strains, JaTH160 and JaOArS982, in neuroblastoma Neuro-2a cells but not in cell lines of extraneural origin. This amino acid did not affect viral loads in the brain or survival curves in mice. These findings suggest that virus propagationin vitromay not reflect the level of virus neuroinvasivenessin vivo.

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