Adhesion to and invasion of HeLa cells by pathogenic Escherichia coli carrying the afa-3 gene cluster are mediated by the AfaE and AfaD proteins, respectively
Adhesion to and invasion of HeLa cells by pathogenic Escherichia coli carrying the afa-3 gene cluster are mediated by the AfaE and AfaD proteins, respectively
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DOI：
10.1128/iai.65.10.4082-4089.1997
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发表时间：
1997-10-01
影响因子：
3.1
通讯作者：
LeBouguenec, C
中科院分区：
文献类型：
--
作者：
Jouve, M;Garcia, MI;LeBouguenec, C
由尿路致病性和腹泻相关的大肠杆菌菌株表达的afa - 3基因簇决定了由AfaD和AfaE - III黏附素组成的无纤毛黏附鞘的形成。对产生这两种黏附素或仅产生其中一种的重组HB101菌株对HeLa细胞的黏附进行了研究。相互作用的超微结构分析和庆大霉素保护试验表明，产生AfaD和AfaE - III两种蛋白的HB101对HeLa细胞有黏附作用，并且一部分细菌内化进入细胞。研究了HeLa细胞与产生AfaD或AfaE - III的HB101突变体，以及与包被纯化的His(6)标记的AfaD或His(6)标记的AfaE - III蛋白的聚苯乙烯微珠之间的相互作用。这些实验表明，AfaE - III允许与HeLa细胞结合，而AfaD介导黏附细菌的内化。His(6) - AfaD - 金复合物与HeLa细胞相互作用的超微结构分析证实，AfaD能够结合到HeLa细胞表面，并表明它通过网格蛋白小泡进入细胞。这些数据表明，afa基因簇在细菌中是独特的，因为它单独编码了对上皮细胞的黏附和侵入。
The afa-3 gene cluster, expressed by uropathogenic and diarrhea-associated Escherichia coli strains, determines the formation of an afimbrial adhesive sheath composed of the AfaD and AfaE-III adhesins. The adherence to HeLa cells by recombinant HB101 strains producing both or only one of these two adhesins was investigated, Ultrastructural analyses of the interaction and gentamicin protection assays showed adherence to HeLa cells by HB101 producing both the AfaD and AfaE-III proteins and internalization of a subpopulation of the bacteria into the cells, The interactions of HeLa cells either with HB101 mutants producing AfaD or AfaE-III or with polystyrene beads coated with purified His(6)-tagged AfaD or His(6)-tagged AfaE-III proteins were studied, These experiments demonstrated that AfaE-III allows binding to HeLa cells and that AfaD mediates the internalization of the adherent bacteria, Ultrastructural analyses of the interaction of His(6)-AfaD-gold complexes with HeLa cells confirmed that AfaD is able to bind to the HeLa cell surface and indicated that it penetrates the cells via clathrin vesicles. These data demonstrate that the afa gene cluster is unique among bacteria, as alone it encodes both adhesion to and invasion of epithelial cells.