Amino Acid at Position 166 of NS2A in Japanese Encephalitis Virus (JEV) Is Associated with In Vitro Growth Characteristics of JEV
Amino Acid at Position 166 of NS2A in Japanese Encephalitis Virus (JEV) Is Associated with In Vitro Growth Characteristics of JEV
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DOI：
10.3390/v12070709
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发表时间：
2020-07-01
期刊：
影响因子：
4.7
通讯作者：
Saijo, Masayuki
中科院分区：
文献类型：
--
作者：
Tajima, Shigeru;Taniguchi, Satoshi;Saijo, Masayuki
我们先前研究发现，日本脑炎病毒（JEV）基因型（GV） Muar株在小鼠神经母细胞瘤细胞中的生长能力明显低于基因型（GI） JEV株Mie/41/2002。在这里，我们试图确定GV - JEV在培养细胞中涉及其低生长潜力的区域。一种含有Mie/41/2002脊椎骨中Muar NS1-3区域的型间病毒（NS1-3(Muar)）在小鼠神经母细胞瘤细胞中的生长能力显著降低。此外，携带Muar NS2A的型间病毒（NS2A(Muar)）在这些细胞中的生长速度也与Muar相似，表明Muar的NS2A是小鼠神经母细胞瘤细胞中具有Muar特异性生长能力的区域之一。对小鼠神经母细胞瘤神经-2a细胞适应的NS1-3（Muar）病毒克隆进行测序分析发现，NS2A 166位的His-to-Tyr突变（NS2A(166)）可以挽救NS1-3（Muar）在神经-2a细胞中的低复制能力。值得注意的是，在NS2A（166）上含有tyrto - his替换的病毒（NS2A(Y166H)）在神经2a细胞中的生长能力比亲本病毒Mie/41/2002低，而基于NS2A（Muar）的突变病毒NS2A（Muar- h166y）在神经2a细胞中的生长能力比NS2A（Muar）高。上述结果提示，乙脑病毒中NS2A（166）氨基酸对乙脑病毒体外生长和组织趋向性至关重要。
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 (NS1-3(Muar)) exhibited a markedly diminished growth ability in murine neuroblastoma cells. Moreover, the growth rate of a Muar NS2A-bearing intertypic virus (NS2A(Muar)) 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 NS1-3(Muar)virus clones revealed that His-to-Tyr mutation at position 166 of NS2A (NS2A(166)) could rescue the low replication ability of NS1-3(Muar)in Neuro-2a cells. Notably, a virus harboring a Tyr-to-His substitution at NS2A(166)(NS2A(Y166H)) showed a decreased growth ability relative to that of the parental virus Mie/41/2002, whereas an NS2A(Muar)-based mutant virus, NS2A(Muar-H166Y), showed a higher growth ability than NS2A(Muar)in Neuro-2a cells. Thus, these results indicate that the NS2A(166)amino acid in JEV is critical for the growth and tissue tropism of JEV in vitro.