Long Polar Fimbriae of Enterohemorrhagic Escherichia coli O157:H7 Bind to Extracellular Matrix Proteins
Long Polar Fimbriae of Enterohemorrhagic Escherichia coli O157:H7 Bind to Extracellular Matrix Proteins
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DOI：
10.1128/iai.05317-11
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发表时间：
2011-09-01
影响因子：
3.1
通讯作者：
Torres, Alfredo G.
中科院分区：
文献类型：
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作者：
Farfan, Mauricio J.;Cantero, Lidia;Torres, Alfredo G.
粘附肠道细胞是肠出血性大肠杆菌 (EHEC) 感染的关键过程。已经描述了几种介导肠出血性大肠杆菌与肠细胞结合的粘附因子，但参与其识别的受体尚未完全表征。细胞外基质 (ECM) 蛋白可能作为受体参与肠道病原体（包括肠出血性大肠杆菌）的识别。在这项研究中，我们试图表征 EHEC O157:H7 与肠道中常见的 ECM 蛋白的结合。我们发现肠出血性大肠杆菌原型菌株以及其他临床分离菌株更充分地粘附在涂有纤连蛋白、层粘连蛋白和 IV 型胶原蛋白的表面上。通过使用针对 LpfA1 假定主要菌毛亚基的抗血清并添加甘露糖，对该表型的进一步表征表明，在长极菌毛 (lpf) 突变体中观察到 EHEC 与 ECM 蛋白的结合减少。我们还发现，H-NS 和 Ler 两种调节因子对 EHEC Lpf 介导的 ECM 结合有影响，支持这些严格调节的菌毛作为粘附因子的作用。纯化的 Lpf 主要亚基与所有测试的 ECM 蛋白结合。最后，当用 ECM 蛋白预孵育的 T84 细胞被肠出血性大肠杆菌感染时，观察到细菌粘附增加。综上所述，这些发现表明 Lpf 和 ECM 蛋白的相互作用有助于肠出血性大肠杆菌在胃肠道的定植。
Adherence to intestinal cells is a key process in infection caused by enterohemorrhagic Escherichia coli (EHEC). Several adhesion factors that mediate the binding of EHEC to intestinal cells have been described, but the receptors involved in their recognition are not fully characterized. Extracellular matrix (ECM) proteins might act as receptors involved in the recognition of enteric pathogens, including EHEC. In this study, we sought to characterize the binding of EHEC O157:H7 to ECM proteins commonly present in the intestine. We found that EHEC prototype strains as well as other clinical isolates adhered more abundantly to surfaces coated with fibronectin, laminin, and collagen IV. Further characterization of this phenotype, by using antiserum raised against the LpfA1 putative major fimbrial subunit and by addition of mannose, showed that a reduced binding of EHEC to ECM proteins was observed in a long polar fimbria (lpf) mutant. We also found that the two regulators, H-NS and Ler, had an effect in EHEC Lpf-mediated binding to ECM, supporting the roles of these tightly regulated fimbriae as adherence factors. Purified Lpf major subunit bound to all of the ECM proteins tested. Finally, increased bacterial adherence was observed when T84 cells, preincubated with ECM proteins, were infected with EHEC. Taken together, these findings suggest that the interaction of Lpf and ECM proteins contributes to the EHEC colonization of the gastrointestinal tract.