Initial binding of Shiga toxin-producing Escherichia coli to host cells and subsequent induction of actin rearrangements depend on filamentous EspA-containing surface appendages
Initial binding of Shiga toxin-producing Escherichia coli to host cells and subsequent induction of actin rearrangements depend on filamentous EspA-containing surface appendages
复制标题
DOI：
10.1046/j.1365-2958.1998.01046.x
复制
发表时间：
1998-10-01
影响因子：
3.6
通讯作者：
Chakraborty, T
中科院分区：
文献类型：
--
作者：
Ebel, F;Podzadel, T;Chakraborty, T
产滋贺毒素的大肠杆菌（STEC）诱导所谓的附着和消退病变，使这些病原体能够紧密粘附于肠道上皮。该过程所需的所有基因都存在于肠上皮细胞消失的位点中，其编码III型分泌系统、分泌的Esp蛋白和表面蛋白intimin。在这项研究中，我们测序的espA基因的STEC，产生并表征了相应的缺失突变体和EspA特异性单克隆抗体，以分析该蛋白在感染过程中的功能作用。EspA在所有附着在Hela细胞上的细菌的装饰结构中被检测到。这些附属物在尚未诱导肌动蛋白酶形成的细菌上特别突出，表明它们介导STEC与其靶细胞的初始接触。因此，espA基因的缺失完全消除了这种STEC突变体与HeLa细胞结合并诱导肌动蛋白重排的能力。类似于本研究中描述的表面附属物也由假单胞菌形成，并且可能代表许多细菌病原体共同的结构元件，其通过III型分泌系统将蛋白质递送到其靶细胞中。
Shiga toxin-producing Escherichia coli (STEC) induce so-called attaching and effacing lesions that enable the tight adherence of these pathogens to the gut epithelium. All of the genes necessary for this process are present in the locus of enterocyte effacement, which encodes a type III secretion system, the secreted Esp proteins and the surface protein intimin. In this study we sequenced the espA gene of STEC, generated and characterized a corresponding deletion mutant and raised EspA-specific monoclonal antibodies to analyse the functional role of this protein during infection. EspA was detected in often filament-like structures decorating all bacteria that had attached to Hela cells. These appendages were especially prominent on bacteria that had not yet induced the formation of actin pedestals, indicating that they mediate the initial contact of STEC to their target cells. Consistently, a deletion of the espA gene completely abolished the capacity of such STEC mutants to bind to HeLa cells and to induce actin rearrangements. Surface appendages similar to those described in this study are also formed by Pseudomonas syringae and may represent a structural element common to many bacterial pathogens that deliver proteins into their target cells via a type ill secretion system.