肠道病毒71型感染小鼠IL-6,TNF-α和脑细胞凋亡的影响

Level of IL-6,TNF-α in Peripheral Blood and Apoptosis of Brain Cells in Mice Infected by Enterovirus 71

目的:观察肠道病毒71型(EV71)感染小鼠外周血IL-6,TNF-α水平的变化及脑细胞凋亡情况,以探讨EV71中枢损害可能的发病机制。方法:建立小鼠EV71感染模型,小鼠根据不同处理因素分为对照组和实验组,用RT-PCR检测感染1天、3天、5天、7天的小鼠脑组织的EV71RNA;分别收集外周血,用ELISA法检测血清细胞因子IL-6,TNF-α的含量;制备单细胞悬液,采用AnnexinV/PI双染结合流式细胞术(FCM)测定小鼠脑细胞的凋亡情况。应用方差分析进行统计学处理。结果(1)实验组于感染第5天和第7天在脑组织中可检测到病毒RNA,对照组脑组织未检测到病毒RNA。(2)实验组血清IL-6,TNF-α水平明显高于对照组(P<0.05),并于24-72h达高峰,此后逐渐下降,于第7天时基本降至正常。(3)实验组小鼠于感染第3天开始出现脑细胞凋亡,于第5天达高峰,第7天时脑细胞凋亡反而降低。结论:EV71具有嗜神经性,EV71感染能促进单核-巨噬细胞分泌IL-6,TNF-α介导全身炎症反应,EV71感染过程中存在脑细胞凋亡现象,可能是其中枢损害的机制之一。

Objective：To observe the concentration of IL-6,TNF-α in mice peripheral blood and apoptosis of brain cells,to explore the possible pathogenesis of central nervous system injury caused by EV71.Methods：An animal model of EV71 infection was created.All mice were divided into two groups：control group and experimental group.EV71 mRNA in mice brain was detected by RT-PCR at different time（1d,3d,5d,7d）postinfection.Production of IL-6,TNF-α was evaluated by ELISA.The apoptosis in mice brain cells was analyzed by Annexin V/PI with flow cytometry.The results were analyzed by analysis of variance.Results：（1）EV71 mRNA could be detected by RT-PCR in brain at 5 days and 7 days postinfection.（2）Levels of IL-6,TNF-α of experimental group were obviously higher than control group（p0.05）.And levels of IL-6,TNF-α reached their peaks at 24-72h postinfection and then declined to the normal level at 7 days postinfection.（3）Apoptosis in mice brain cells can be detected at 3 days after infection,and levels reached their peaks at 5d postinfection.Levels of brain cells apoptosis were declined at 7d after infection.Conclusion：EV71 can cause injury to central nervous system.EV71 infection can induce secretion of IL-6,TNF-α by mononuclear phagocyte to induce systemic inflammatory response.EV71 infection can induce apoptosis in brain cells,and this may play an important role in EV71 infection.