摘要
树鼩是灵长类动物的近亲,且具有体型小、繁殖周期短、饲养管理成本低等优点,长期以来被认为有望替代灵长类动物用于人类疾病的动物模型研究。该文研究了肠道病毒EV71对幼年中缅树鼩的感染特点,探索建立EV71感染树鼩动物模型及替代灵长类动物的可行性。实验分别采用灌胃、滴鼻和尾静脉注射3种方式,感染3月龄树鼩,定期观察动物临床症状和血常规变化和定期采集血液和粪便样品,并使用中和抗体试验、reverse transcription-PCR(RT-PCR)和Real-TimePCR等技术,检测相关样品中和抗体效价、病毒核酸及载量变化。结合组织病理学检查,分析感染病变特点。研究结果发现,实验组树鼩体温在第4天前后开始升高,白细胞、淋巴细胞也有类似趋势;3种攻毒方式均可检测到病毒载量,峰值出现在第10天前后,灌胃途径尤为明显,血清的最大中和抗体效价为1:16。感染EV71病毒的树鼩2周左右出现急性松弛性瘫痪,大体解剖发现伴有尿潴留症状,组织病理学检查发现在脑、肺、肠、脾脏、肾脏等部位发生病变。结果表明,EV71病毒通过灌胃、滴鼻和静脉注射3种方式均可以感染中缅树鼩,并使之出现神经系统及相关病变,该实验为将来研究EV71感染树鼩致病机理、建立手足口病树鼩动物模型奠定了理论基础。
Tupaia belangeri are small mammals with a squirrel-like appearance;they were formerly classified under the primates order despite the lack of derived features characteristic of primates.Given that T.belangeri are easy to raise,cheap to maintain,and have a small body size,a high reproductive rate,and close affinity to primates,these animals would be used as an alternative to primates in biomedical research.Three-month old T.belangeri chineses were infected with enterovirus 71（EV71） via three different routes,namely,oral administration,nasal dripping,and tail intravenous injection,to study the infection in infant T.belangeri and find a feasible scheme to make them an ideal animal model of EV71 in place of primates.Daily activities were regularly observed,body temperatures were measured,and blood tests were conducted.Blood and fecal samples were regularly collected.The infection was examined via the neutralizing antibody test,reverse transcription polymerase chain reaction（RT-PCR）,Real-Time PCR,and pathological analysis.The temperature,as well as the white blood cell count and the number of lymphocytes,increased four days after infection.Virus loads were determined in all three groups,and the peak appeared on,before,or after the tenth day,respectively.Thus,oral administration proved to be the best route.The highest serum antibody titer obtained was 1：16.Acute paralysis with urinary retention manifested after about two weeks,and pathological changes were observed in the brain,heart,lung,spleen,kidney,and other tissues.In conclusion,T.belangeri chineses can infected with EV71 via oral administration,nasal dripping,and tail intravenous injection.Therefore,T.belangeri are potential EV71 animal models for further studies on the mechanism of pathogenesis or vaccine evaluation.
基金
"十一五"国家科技支撑计划项目(2009BAI83B02
2011BAI15B01)
云南省科技基础条件平台建设计划项目(2006PT07-2)
国家"973"计划项目(2011CB504903)
国家自然科学基金(81171573)
云南省应用基础研究计划面上项目(2011FB116)
关键词
手足口病
EV71
中缅树鼩
动物模型
Hand-foot-mouth disease
EV71 virus
Tupaia belangeri chineses
Animal model
