模拟人类巨细胞病毒(HCMV)先天性中枢神经系统感染小鼠模型的建立

DEVELOPMENT OF A MOUSE MODEL OF HUMAN CYTOMEGALOVIRUS INEFCTION THAT MIMICS HUMAN CONGENITAL CENTRAL NERVOUS SYSTEM INFECTION

目的寻找适合的研究 HCMV 先天性 CNS 感染是过程的动物模型。方法将人巨细胞病毒(HCMV)接种至6～8周龄 Balb/c 雌雄小鼠腹腔后,交配。待雌鼠临产时剖腹取出胎鼠脑双侧大脑皮层,进行病毒分离,病理学检测及用地高辛标记的 HCMV 寡核苷酸探针对大脑皮层细胞压印片进行原位分子杂交检测。结果病理学结果证实,鼠脑为侵袭性脑膜脑炎性病理改变,并在神经细咆内发现病毒特征性的大的核内嗜碱性包涵体;原位杂交结果显示,病毒核酸存在于受染神经细胞及神经胶质细胞核内及胞浆内;在鼠脑组织上清液中分离出 HCMV。且感染雌鼠所生子鼠死胎率及出生后一周内病死率明显高于正常对照组(P<0.005)。证明该病毒能侵袭Balb/c 小鼠,并通过胎盘感染其子代的中枢神经系统(CNS)。结论这种模拟人类 HCMV 先天性 CNS 感染的小鼠模型的建立所显示的许多相似的感染和病理过程,为进一步研究 HCMV 先天性 CNS 感染的病理过程和疫苗的应用提供了可能。

Aim To define that Human Cytomegalovirus （HCMV-AD169）can cross the placenta of the BALB/C mice and initiate congenital infection of the developing fetus and find suitable animal mode.Methods HCMV- AD169(5.0log TCID50 in 0.5ml/mouse)was injected into the intraperitoneum of mice （half of mice are female） when they were about 8～12 weeks old.Then,these of mice were used for mating.Pregnancies were dated as day 0 when a copulation plug was found.Fetuses on day about to give birth of gestation were removed from the utcri and the its cerebral cortex was removed from the skull and fixed with 4 % paraformaldehyde,then cut into serial coronal sections 5μm thick,applided to slides coared with Histostik,and then stained with hematoxylin and eosin （HE）.Meanwhile,the supernatant of minced a fetal mouse brain tissue was used for virus isolates by HF cells. And viral DNA- postitive cells were examined by in situ hybridization using digoxigenin labelled HCMV DNA oligonucleotide probe in the acetone fixed imprint off the cerebral cortex.Results Pathological changes consist- ing of destructive meningoencephalitis and large; basophilic; intranuelear and acidophilous intracytoplasmic neu- ronal inclusions of viral type occurred in the fetal mouse brain.Meanwhile the presence of virus sequences was confirmed by in siru hybridization,bowever,nothing was found in the normal controls;HCMV had also been iso- lated from the tissue supernatant.The positive rate of serum specific IgM and IgG of the female mice in HCMV infection group was 73.9 % and 95.7 % resoectively,and that of normal control group was 4.2 % and 12.5 % re- specrively by ELISA.The results showed there are significant difference between two groups（P< 0.01 ）.And the stillibirth rate and the mortality within the first week at birth of the off spring which were beared by ist mothers injected with HCMV were much evidently higher than those of the normal control（P<0.01）.Conclusion The central nervous system（CNS）of a fetal mouse becomes infected as a result of transplacental transmission of HCMV during symptomstic maternal infection.The mouse model will allow the study of the pathogenesis of HCMV congenital CNS infection and the development of therapeutic agents and vaccinse.