摘要
为研究肠道病毒71型(Enterovirus 71,EV-A71)经不同攻毒方式感染不同日龄ICR乳鼠的感染情况,了解EV-A71在小鼠体内的动态分布和感染机制,为建立EV-A71感染动物模型,本研究采用分离自重症手足口患儿的EV-A71毒株,分别通过肌肉注射(Intramuscular injection,IM)、腹腔注射(Intraperitoneal injection,IP)以及脑内注射(Intracerebral injection,IC)的方式感染3日、5日和9日龄ICR乳鼠,感染后定期采集血液和各组织,通过Realtime PCR追踪各组织中病毒载量变化,并且通过切片制作和免疫组化对感染乳鼠进行病原学和病理学分析。结果显示:对于低日龄(≤5日龄)乳鼠,注射剂量在104.5 TCID50/g·体重时IM、IP及IC均为较好的感染方式,都会出现神经症状,且有极高的致死率。随着日龄增长,感染后症状有所减轻,但IM和IP感染途径对大日龄乳鼠仍具有良好的致病性,且IM和IP死亡率显著高于IC死亡率。经IM、IP和IC注射感染病毒的3日龄乳鼠在6dpi体重相对于各对照组分别下降了1.54g(31.43%)、1.31g(15.06%)和2.52g(44.28%),而经IM和IP感染的5日龄乳鼠6dpi体重相对于各对照组分别下降了0.605g(8.95%)、0.886g(15.51%),经IC感染的5日龄乳鼠6dpi体重相对于对照组上升了0.904g(14.70%),感染组体重均显著低于对应的同期对照组(P<0.05)。经IM、IP和IC感染病毒的3日龄乳鼠9dpi均死亡,而5日龄乳鼠9dpi存活率分别为42.8%、25%和87.5,14dpi存活率分别为0%、0%和25%,9日龄乳鼠9dpi存活率分别为70%、84.62%和100%。病理学及免疫组化检查显示EV-A71病毒具有强烈的嗜神经性及嗜骨骼肌的特性,可导致病毒血症、脑神经元及骨骼肌坏死、心肌间质水肿及多脏器炎症反应。我们系统地研究了不同攻毒方式感染不同日龄的ICR乳鼠后的病毒动态分布及免疫病理损伤,发现经肌肉注射或腹腔注射5日龄乳鼠能够建立理想的EV-A71感染动物模型。
We aimed to study infections in neonatal ICR mice of different ages infected with Enterovirus 71（EV-A71）through three routes of infection,and to explore the dynamic distribution and infection mechanism of EV-A71 in vivo.Three-,5-and 9-day-old neonatal ICR mice were infected with an EV-A71 strain isolated from a child with severe hand,foot and mouth disease through intramuscular（IM）,intraperitoneal（IP）and intracerebral（IC）injection,respectively.Consequently,blood,brain,hind-limb muscle,heart,and intestines of mice were collected at regular intervals.Changes in viral load in organs were measured using real-time polymerase chain reaction.Hematoxylin and eosin staining and immunohistochemical（IHC）analyses were undertaken to detect pathogenic and pathologic changes in infected mice.Five-day-old neonatal mice infected with EV-A71 through IM,IP or IC routes had obvious neurologic symptoms and a high mortality rate.Symptoms were alleviated slightly with increasing age of mice upon injection.However,the pathogenicity associated with IM and IP injections was more severe than that of IC injection.Also,the mortality rates of IM and IP injections were significantly higher than that of IC injection.Compared with the control group,the mean body weight（in g）of 3-day-old neonatal mice at 6days post-infection（dpi）injected by IM,IP and IC routes decreased by 1.54（31.43%）,1.31（15.06%）and 2.52（44.28%）,respectively.Similarly,the mean body weight（in g）of 5-day-old neonatal mice at 6dpi injected by IM and IP decreased by 0.605（8.95%）,0.886（15.51%）,whereas that of mice injected by IC increased by 0.904（14.70%）.The body weight of all infection groups was significantly lower than that of the control group（P〈0.05）.All 3-day-old neonatal mice infected with EV-A71 through IM,IP and IC routes died at 9dpi.Survival rates of 5-day-old neonatal mice infected through IM,IP and IC routes at 9dpi and14 dpi were 42.8%,25%,and 87.5%,and 0%,0%,and 25%,respectively.Those of 9-day-old neonatal
出处
《病毒学报》
CAS
CSCD
北大核心
2016年第6期671-682,共12页
Chinese Journal of Virology
基金
山东省自然科学基金(项目号:ZR2015JL026
ZR2014HP068)
题目:通过不同性质RNA表达谱差异研究肠道病毒71型引起手足口病重症的分子机制-省属高校优青
手足口病柯萨奇A组病毒流行病学调查和致病性研究
山东省"泰山学者工程专项经费"
