大肠杆菌在巨噬细胞中的降解与交叉递呈研究  

Degradation and cross-presentation of Escherichia coli in macrophage

作　　者：刘娜[1] 吴玉章[1] 周镜然[1] 邹丽云[1] 郭晟[1] 万瑛[1] 

机构地区：[1]第三军医大学基础医学部全军免疫学研究所,重庆400038

出　　处：《第三军医大学学报》2006年第24期2410-2412,共3页Journal of Third Military Medical University

基　　金：国家自然科学基金资助项目(30400392)~~

摘　　要：目的通过表达的红色荧光蛋白(DsRed)与卵白蛋白(ovalbumin,OVA)表位融合蛋白,研究表达此融合蛋白的大肠杆菌在巨噬细胞中降解与交叉递呈的时相。方法构建红色荧光蛋白与卵白蛋白表位融合蛋白的原核表达质粒(pET-16bOR),流式细胞计数仪检测表达融合蛋白的大肠杆菌,然后动态观察此大肠杆菌在巨噬细胞中的降解与交叉递呈。结果表达红色荧光蛋白(DsRed)与卵白蛋白(ovalbumin,OVA)表位融合蛋白的大肠杆菌能被488nm波长激发荧光。在巨噬细胞中,内质网与吞噬的大肠杆菌共聚;吞噬的大肠杆菌3～5h快速降解;而在此时相产生的H-2Kb-OVA257-264复合物达到顶峰。结论表达此红荧光蛋白与OVA表位融合蛋白的大肠杆菌具有荧光特性,内质网参与大肠杆菌吞噬体形成,巨噬细胞吞噬大肠杆菌后3～5h是抗原快速降解和交叉递呈的时相。Objective To dynamically investigate the cross-presentation and degradation of E. coli. that expresses a fusion protein DsRed tagged OVA epitope antigen in macrophage. Methods A plasmid that contains the expression element of fusion protein DsRed tagged OVA epitope was constructed and expressed in E. coll.. The cross-presentation and degradation of the E. coli. in macrophage were dynamically assessed with cytometry by using a MHC class Ⅰ -peptide complex antibody. Results The expression of recombinant protein was confirmed by cytometry by 488 nm excitation. The phagosome containing E. coli. co-localized with endoplasmic reticulum （ER）. The phagocytosed E. coli. degraded rapidly in 3 -5 h and at same phase the H-2Kb- OVA257-264 complex reached the maximum. CoNclusioN The E. coli. containing recombinant protein has similar fluorescence with DsRed. ER mediates the phagocytosis of E. coll.. The cross-presentation and degradation of E. coli., are mainly completed in 3 - 5 h after phagocytosis.

关 键 词：红色荧光蛋白 抗原递呈 交叉递呈 

分 类 号：R378.21[医药卫生—病原生物学] R392.12[医药卫生—基础医学]