卵蛋白致敏小鼠对呼吸道合胞病毒感染的免疫应答

Immune Response to Respiratory Syncytial Virus Infection in Ovalbumin Sensitized Mice

目的探讨卵蛋白(OVA)致敏小鼠感染呼吸道合胞病毒(RSV)后肺内炎症及T辅助细胞相关细胞因子变化的特点。方法将Balb／c小鼠随机分成正常未致敏和致敏(用OVA雾化吸入)2个系列。每个系列中又包括对照组、RSV感染组。以肺组织病理检测和IL-4、IFN-γmRNA表达作为评价指标。结果病理检查证实小鼠感染RSV后发展为典型的间质性肺炎;致敏小鼠感染RSV后病变更明显,细支气管周围淋巴细胞浸润形成管套增厚,嗜酸细胞增多,炎性细胞浸润的细支气管比例显著增高。单纯RSV感染小鼠肺组织IFN-γ mRNA有显著表达,但无IL-4 mRNA表达;致敏小鼠感染RSV 后IL-4 mRNA的表达显著,但 IFN-γ mRNA几乎不表达。结论致敏小鼠感染RSV后肺组织病变较单纯RSV感染者严重;单纯RSV感染后小鼠肺组织T辅助细胞因子改变呈Th1反应,而致敏后再感染RSV后则呈Th2反应。

Objective To observe the lung inflammation and the expression of T - helper cell related cytokines in respiratory syncytial virus （RSV） infected Balb/c mice pre - sensitized with ovalbumin （OVA）. Methods Mice were randomly divided into two series： nonsensitized and sensitized animal model with nebulized OVA once a day for 10 days. Each of the series was divided again into two groups： control group, RSV infected group with nasal droping plus nebulizing. All the mice were sacrificed 5 days later of infection. Viral isolation of lung organization was performed in each group. Pulmonary pathological detection and the levels of interleukin - 4 （IL - 4）, interferon - γ （IFN - γ） mRNA were evaluated by RT - PCR. Results The RSV were found only in RSV infected groups. The Balb/c mice developed typical interstitial pneumonia after RSV infection. When the mice pre - sensitized were infected with RSV, the pulmonary inflammation, lymphocyte and eosinophils infiltration and cell - collar peribronchiles were more severe in lung organization and bronchiole than those in the single RSV infection group. In the lung organization of control group, there were no mRNA expression of IL - 4 and IFN - γ. The mRNA of IFN - γ was expressed in the lung organization of RSV infected groups while had not showed mRNA of IL - 4. In the OVA ＋ RSV group the mRNA expression of IL - 4 was obvious, while the expresses of IFN - γ scarcely. Conclusions Pulmonary inflammation is more severe in the infection after OVA sensitization. RSV infection alone results in a Th1 - like cytokine response, while the infection after OVA sensitization results in Th2 - like response.