小鼠呼吸道合胞病毒感染模型的建立

Establishment of respiratory syncytial virus infection model in mice

目的 建立呼吸道合胞病毒 (RSV)感染小鼠模型 ,了解病程规律及病理变化 ,为研制抗RSV药物打下基础。方法 给小鼠感染不同负荷量RSV(10 3、10 4 、10 5、10 6 PFU) ,并于小鼠感染 10 6 PFURSV后不同时间 (1、2、3、4、5、6、7d)取右肺组织作空斑形成实验检测肺组织RSV滴度 ,左肺组织行HE染色、电镜检查及原位杂交检测RSV定位表达。结果 病毒感染量为 10 3PFU时肺组织无空斑形成 ,随着感染病毒量增大 ,肺组织病毒增多。鼠感染 10 6 PFU后 ,随着时间推移 ,肺内病毒量降低 ,感染第 6天的肺组织已无空斑形成。病理显示RSV感染第 3天肺组织炎症性变化最明显 ,感染第 7天肺部炎症细胞减少 ,但出现了部分肺泡壁断裂融合 ,肺泡腔扩大。原位杂交证实RSV主要侵袭支气管、细支气管上皮细胞及肺泡上皮细胞。结论 经鼻内滴入RSV可建立小鼠感染模型 。

Objective To establish a model of respiratory syncytial virus infection (RSV) in mice and explore the course of pathologic changes. Methods Twelve mice were anesthetized and inoculated through intranasal injection of 100μL of RSV at 10 3, 10 4, 10 5 and 10 6 plaque forming unit (PFU), and then were sacrificed on the following day. Another twenty-one mice were inoculated with 10 6 PFU RSV, and killed at different times. Their right lungs were removed in aseptic condition to detect the quantity of virus consecutively. Left lungs were collected for histopathological and electromicroscopic examination, and in situ hybridization was applied to locate the virus. Results As the RSV dose increased, the virus in the lungs increased at a titer of 10 4 PFU and more. Virus in the lungs decreased with time. After 6 days of infection, no plaque could be detected in the lungs. On the third day of infection, severe lung inflammation was detected. On the 7th day of infection, desquamated and confluenced alveolar epithelia and enlarged alveolar space were found in the lungs. Electromicroscopic examination showed that alveolar epithelium typeⅡ was more sensitive to RSV infection and had developed severe lesion. In situ hybridization demonstrated that RSV presented in bronchial, bronchiole and alveolar epithelial cells. Conclusion Nasal drip of RSV may induce RSV infection model in mice, so it may be used to assess the effect of specific anti-RSV drugs.