Identification of two amino acids within E2 important for the pathogenicity of chimeric classical swine fever virus
Identification of two amino acids within E2 important for the pathogenicity of chimeric classical swine fever virus
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E2内两个氨基酸的鉴定对嵌合猪瘟病毒的致病性很重要
DOI：
10.1016/j.virusres.2015.10.006
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发表时间：
2016-01-04
期刊：
影响因子：
5
通讯作者：
Pan, Zishu
中科院分区：
文献类型：
--
作者：
Wu, Rui;Li, Ling;Pan, Zishu
本课题组前期研究表明，以猪瘟强毒株石门株（VSM）为遗传背景，构建了猪瘟疫苗C株E2基因的嵌合疫苗vSM/CE 2，经PK 15细胞连续传代后，毒力恢复。为探讨致病性的分子基础，对第11代vSM/CE 2变异株（vSM/CE 2-p11）进行了基因组测序，发现vSM/CE 2-p11的E2区存在T745 I和M979 K两个氨基酸突变。基于嵌合cDNA克隆pSM/CE 2的反向遗传操作，拯救了突变病毒vSM/CE 2/T745 I、vSMCE 2/M979 K和vSM/CE 2/T745 I; M979 K。感染猪的数据表明，M979 K氨基酸取代是致病性的原因。体外研究表明，T745 I和M979 K增加了感染性病毒的产生和复制。我们的研究结果表明，位于E2的745和979位的两个残基在决定嵌合CSFV vSM/CE 2的体外复制和体内致病性中起关键作用。(C)2015 Elsevier B. V.版权所有。
Our previous study demonstrated that a chimeric classical swine fever virus (CSFV) vSM/CE2 containing the E2 gene of the vaccine C-strain on the genetic background of the virulent CSFV strain Shimen (vSM) was attenuated in swine but reversed to virulence after serial passages in PK15 cells. To investigate the molecular basis of the pathogenicity, the genome of the 11th passage vSM/CE2 variant (vSM/CE2-p11) was sequenced, and two amino acid mutations, T745I and M979K, within E2 of vSM/CE2-p11 were observed. Based on reverse genetic manipulation of the chimeric cDNA clone pSM/CE2, the mutated viruses vSM/CE2/T745I, vSMCE2/M979K and vSM/CE2/T745I; M979K were rescued. The data from infection of pigs demonstrated that the M979K amino acid substitution was responsible for pathogenicity. Studies in vitro indicated that T745I and M979K increased infectious virus production and replication. Our results indicated that two residues located at sites 745 and 979 within E2 play a key role in determining the replication in vitro and pathogenicity in vivo of chimeric CSFV vSM/CE2. (C) 2015 Elsevier B.V. All rights reserved.