腸毒性大腸桿菌是發(fā)展中國家最常見的腹瀉原因，也是旅行者腹瀉的主要原因,。粘附到宿主細(xì)胞上是這種及很多其他種細(xì)菌病原體致病所必需的,。
現(xiàn)在，研究人員發(fā)現(xiàn)了大腸桿菌的一個(gè)新的粘附機(jī)制,，該機(jī)制依賴于體內(nèi)分泌的蛋白EtpA,。該蛋白與細(xì)菌鞭毛頂端的鞭毛蛋白分子的保留區(qū)域發(fā)生相互作用，在那里它形成細(xì)菌與宿主細(xì)胞之間的一個(gè)粘附分子橋,。這一發(fā)現(xiàn)是證明EtpA（以及保留下來的鞭毛蛋白配體）有可能是針對(duì)大腸桿菌及其他運(yùn)動(dòng)病原體（motile pathogen）的疫苗的有效抗原目標(biāo)的又一個(gè)證據(jù),。（生物谷Bioon.com）
Bioon推薦原始出處：
Nature 457, 594-598 (29 January 2009) | doi:10.1038/nature07568
Enterotoxigenic Escherichia coli EtpA mediates adhesion between flagella and host cells
Koushik Roy1, George M. Hilliard2, David J. Hamilton3, Jiwen Luo1, Marguerite M. Ostmann4 & James M. Fleckenstein1,2,5
1 Department of Medicine,
2 Department of Molecular Sciences,
3 Department of Comparative Medicine, University of Tennessee Health Science Center, 956 Court Avenue, Memphis, Tennessee 38163, Tennessee, USA
Adhesion to epithelial cells1 and flagella-mediated motility are critical virulence traits for many Gram-negative pathogens, including enterotoxigenic Escherichia coli (ETEC)2, a major cause of diarrhoea in travellers and children in developing countries3, 4. Many flagellated pathogens export putative adhesins belonging to the two-partner secretion (TPS) family5. However, the actual function of these adhesins remains largely undefined. Here we demonstrate that EtpA, a TPS exoprotein adhesin of enterotoxigenic E. coli 6, mimics and interacts with highly conserved regions of flagellin, the major subunit of flagella, and that these interactions are critical for adherence and intestinal colonization. Although conserved regions of flagellin are mostly buried in the flagellar shaft7, our results suggest that they are at least transiently exposed at the tips of flagella where they capture EtpA adhesin molecules for presentation to eukaryotic receptors. Similarity of EtpA to molecules encoded by other motile pathogens suggests a potential common pattern for bacterial adhesion, whereas participation of conserved regions of flagellin in adherence has implications for development of vaccines for Gram-negative pathogens.
