人巨细胞病毒先天感染小鼠大脑皮质的病理学特征

PATHOLOGIC FEATURE ON THE CEREBRAL CORTEX OF THE BALB/C FETAL MICE OF CONGENITAL HUMAN CYTOMEGALOVIRUS INFECTION

目的 研究人巨细胞病毒（ Ｈ Ｃ Ｍ Ｖ） 经小鼠胎盘垂直传播致胎鼠大脑皮质感染的病理学特征。方法 在８ ～１２周龄 Ｂ Ａ Ｌ Ｂｃ 雌雄小鼠腹腔内接种 Ｈ Ｃ Ｍ Ｖ 后， 交配， 待孕鼠妊娠第７ 天及临产时处死动物； 无菌将雌胎鼠双侧大脑皮质取出， 应用常规组织切片 Ｈ Ｅ 染色、脑压印片地高辛标记 Ｈ Ｃ Ｍ Ｖ 寡核苷酸探针原位杂交及病毒分离的方法进行检测分析。结果 组织学检查发现， 雌、胎鼠脑微血管扩张充血， 脑实质有中性粒细胞和单核细胞浸润， 部分神经细胞已变性坏死。在胎鼠脑组织切片上， 还可见到软化灶及受染神经细胞核内 Ｈ Ｃ Ｍ Ｖ 特征性嗜碱性包涵体。原位杂交显示， 病毒核酸存在于待产胎鼠脑神经细胞及胶质细胞核内及胞浆内。在胎鼠脑组织悬液中分离出该病毒。结论 Ｈ Ｃ Ｍ Ｖ 能通过 Ｂ Ａ Ｌ Ｂｃ 小鼠胎盘致发育中子鼠大脑皮质感染， 发生侵袭性脑膜脑炎性病理改变。

AimTo study the pathologic feature that Human Cytomegalovirus AD169 strain (HCMV AD169) could cross the placenta of the Balb/c mice and initiate congenital infection of the fetus cerebral cortex.MethodsHCMV(5 0 log TCID 50 in 0 5 ml/mouse) was injected into the intraperitoneum of mice (half of mice are female)when they were about 8～12 weeks old.These of mice,then,were used for mating.Pregnancies were dated as day 0 when a copulation plug was found.Fetuses on day 7 of gestation and about to be given birth were removed from the uteri and its cerebral cortex were removed from the skull,respectively.The specimens were fixed in 4% buffered solutions of paraformaldehyde,then,were sectioned and stained with HE.The viral DNA-positive cells were examined by in situ hybridization using digoxigenin labelled HCMV DNA oligonucleotide probes in the imprint of the cerebral cortex fixed with acetone.Meanwhile,the supernatants of minced fetal mouse brain tissue were used for virus isolation by HF cells.ResultsMicroscopically,it were found that the capillary was dilated and congested in the brain of the pregnant mice and its fetuses,the parenchyma was infiltrated with neutrophils and mononuclear cells,and,degeneration and necrosis of neurons and large,basophilic,inrtranuclear neuronal inclusions of viral type occurred in the fetal cerebral cortex.The presence of virus sequences was confirmed by in situ hybridization,HCMV was isolated from the supernatant.However,nothing was found in the control groups.ConclusionHCMV could cross the placenta of the Balb/c mice and initiate congenital infection of cerebral cortex in the developing fetus and pathological changes consisting of destructive meningoencephalitis. \ \