肠道病毒71型温度适应性进化对毒株毒力的影响研究

  目的  研究EV71病毒温度适应性进化过程中的毒力变异，为相关手足口病的防控提供参考。  方法  以EV71姊妹株（谱系#100、#101）亲代株、各温度适应株分别感染Vero细胞，进行噬斑实验验证、CCK-8细胞毒性实验、Vero细胞感染后宿主蛋白质组学研究，确认表型差异、比较不同毒株细胞抑制率，质谱检测并分析宿主细胞差异表达蛋白的功能。  结果  确认Vero细胞感染热适应株（谱系#101）后发生噬斑变异；各温度适应株细胞抑制率较亲代株均有增长，但增幅不同。聚类分析与主成分分析显示，Vero细胞感染后宿主蛋白质组表达热适应株与亲代株、冷适应株与常温适应株分别具有相似性，组间差异表达蛋白500种（上调蛋白239种，下调蛋白261种）；其中上调蛋白功能与转录后蛋白修饰等功能有关，下调蛋白则与SRP依赖性共翻译蛋白的膜定位/易位、逆蛋白转运有关。  结论  EV71病毒在温度适应性进化中可能伴随毒力变异，其作用机制有待进一步研究。

Investigation of Virulence Variation of Enterovirus 71 Strains during Thermal Adaptive Evolution

  Objective   To study the virulence variation of enterovirus 71 (EV71) during thermal adaptive evolution, providing references for the prevention and control of the EV71-related hand, foot and mouth disease.   Methods   Parental strains and thermal-adapted strains originating from EV71 sibling strains (lineage #100 and #101) were used for plaque assay validation, CCK-8 cytotoxicity experiment, and host proteomics studies after Vero cell infection. Plaque morphology and cell inhibition rate of the viral strains were obtained. Mass spectrometry was used to examine and analyze the functions of proteins that were differential expressed in the host cells.   Results   Plaque morphology variation was found only in the heat-adapted strain of lineage #101. Increase in cell inhibition rate was observed in all the thermal-adapted strains, but the amount of increase varied in different strains. According to the results of clustering analysis and principal component analysis, after infection of Vero cells, the host cell protein profile of the heat-adapted strains was similar to that of the parental strains and the host cell protein profile of cold-adapted strains was similar to that of cell-adapted strains. It showed that 500 kinds of proteins presented inter-group difference in their expression, with 239 kinds being up-regulated proteins and 261 being down-regulated. The function of the up-regulated proteins were related to post-translational protein modification, while the functions of the down-regulated proteins were related to SRP-dependent cotranslational protein translocation/targeting to membrane and retrograde protein transport.  Conclusion   Virulence variations of enterovirus 71 may accompany thermal adaptive evolution, but its mechanism of action still awaits further investigation.