肠道病毒71型3CD蛋白对细胞的损伤作用

目的 研究肠道病毒71型(EV71)3CD蛋白在致病机制中的作用。方法 实验分为对照组、SDLY1组、SDLY107组和SDLY107(1-3CD)组。通过反向遗传技术将弱毒株SDLY1株的3CD蛋白编码区置换到强毒株SDLY107株,形成拯救病毒SDLY107(1-3CD)株。将EV71病毒接种于RD细胞和Vero细胞,于37℃和39.5℃孵育一定时间后,采用MTT试验检测活细胞量,以判断病毒对细胞损伤作用的改变。结果 37℃下,拯救病毒SDLY107(1-3CD)对细胞的损伤作用弱于SDLY107株,但仍强于SDLY1株(P<0.05);39.5℃下,拯救病毒SDLY107(1-3CD)株对细胞的损伤作用较SDLY107株下降(P<0.05),但与SDLY1株的差异无统计学意义(P>0.05)。结论 EV713CD编码区的置换可以改变病毒对细胞的损伤作用,3CD蛋白编码区可能存在影响病毒毒力的位点。这一发现有助于理解EV71的致病机制。

Cell injury induced by 3CD protein of Enterovirus 71

Objective To investigate the roles of 3CD protein on pathogenesis of Enterovirus 71(EV71). Methods The cells were divided into control group, SDLY1 group, SDLY107 group, and SDLY107(1-3CD) group. 3CD region of SDLY107, which was isolated from the severe case, was replaced by that of SDLY1, which was isolated from the mild case, through reverse genetics, and the recombinant virus was named as SDLY107(1-3CD). EV71 strains were incubated at 37℃ and 39.5℃. After some time, the living cells were detected by MTT assay to show cell injury induced by different strains. Results Compared with SDLY107, cell injury induced by SDLY107(1-3CD) decreased at 37℃ and 39.5℃ (both P<0.05). There was statistical difference between cell injury induced by SDLY1 and SDLY107(1-3CD) at 37℃ (P<0.05), while there was no statistical difference between cell injury induced by SDLY1 and SDLY107(1-3CD) at 39.5℃(P>0.05). Conclusion Replacement of EV713CD can change cell injury induced by EV71, and there may be virulence determinants on 3CD region, which may help us understand the pathogenesis of EV71.