卡氏肺孢子虫感染大鼠模型的建立及表面糖蛋白基因的克隆

Establishment of rat model for Pneumocystis carinii infection and cloning of the surface glycoprotein A gene of Pneumocystis carinii

目的建立卡氏肺孢子虫感染大鼠模型并对卡氏肺抱子虫表面糖蛋白基因进行克隆,为进一步对该基因进行表达作前期准备。方法 以地塞米松对大鼠进行免疫抑制,2周后喂于感染卡氏肺孢子虫的大鼠肺组织匀浆,再免疫抑制4周,诱导鼠模产生。经光镜及PCR检测证实阳性后,用PCR法扩增出卡氏肺孢子虫的表面糖齿白基因并亚克隆入T载体,转化JM109大肠杆菌。结果 经光镜和PCR检测证实实验组大鼠均感染了卡氏肺孢子虫;PCR产物经琼脂糖电泳后,扩增片段的长度为319bp。结论通过地塞米松免疫抑制和一次性喂予病原体可以建立卡氏肺孢子虫感染大鼠模型。

Objective To establish a rat model for Pneumocystis carnii infection and to clone surface glycoprotein A (GpA)gene of Pneumocystis carni. Methods Immunosuppression was induced in 5 rats with an immunosuppresion regimen consisting mainly of dexamethasone in a course of 2 weeks, after which pulmonary homogenates of rats infected with Pneumocystiscarinii were fed to the immunosuppressed rats. Immunosuppression was maintained for approximately 4 weeks after the feedingto induce Pneumocystis pneumonia in the rats. GpA gene was subsequently amplified from the rats with pneumonia as con-firmed by microscope and PCR detection, and was subcloncd into T-vector for the transformation of Escherichia coli JM109strain. Results Pneumocystis carinii was detected by microscope and PCR detection in rats with immunosuppression. Thelength of PCR product was 319 bp as shown by agarose electrophoresis. Conclusion The rat model of Pneumocystis cariniiinfection can be established by immunosuppression with dexamethasone and a single oral administration of the pathogen.