Antimicrobial Resistance, Omics and Microbiota Group, Department of Biosciences, Nottingham Trent University, Nottingham NG1 4FQ, UK.
Int J Mol Sci. 2020 Jun 8;21(11):4102. doi: 10.3390/ijms21114102.
Enteric pathogens rely on a variety of toxins, adhesins and other virulence factors to cause infections. Some of the best studied pathogens belong to the Enterobacterales order; these include enteropathogenic and enterohemorrhagic , spp., and the enteropathogenic . The pathogenesis of these organisms involves two different secretion systems, a type 3 secretion system (T3SS) and type 5 secretion systems (T5SSs). The T3SS forms a syringe-like structure spanning both bacterial membranes and the host cell plasma membrane that translocates toxic effector proteins into the cytoplasm of the host cell. T5SSs are also known as autotransporters, and they export part of their own polypeptide to the bacterial cell surface where it exerts its function, such as adhesion to host cell receptors. During infection with these enteropathogens, the T3SS and T5SS act in concert to bring about rearrangements of the host cell cytoskeleton, either to invade the cell, confer intracellular motility, evade phagocytosis or produce novel structures to shelter the bacteria. Thus, in these bacteria, not only the T3SS effectors but also T5SS proteins could be considered "cytoskeletoxins" that bring about profound alterations in host cell cytoskeletal dynamics and lead to pathogenic outcomes.
肠病原体依赖于多种毒素、黏附素和其他毒力因子来引起感染。一些研究得最好的病原体属于肠杆菌目;这些包括肠致病性和肠出血性、 和 ，以及肠致病性 。这些生物体的发病机制涉及两种不同的分泌系统，一种是 III 型分泌系统 (T3SS) 和 V 型分泌系统 (T5SSs)。T3SS 形成一个类似于注射器的结构，跨越细菌膜和宿主细胞质膜，将毒性效应蛋白易位到宿主细胞质中。T5SSs 也被称为自转运体，它们将自身多肽的一部分输出到细菌细胞表面，在那里发挥作用，如与宿主细胞受体结合。在这些肠病原体感染期间，T3SS 和 T5SS 协同作用，导致宿主细胞细胞骨架的重排，无论是入侵细胞、赋予细胞内运动性、逃避吞噬作用还是产生新的结构来保护细菌。因此，在这些细菌中，不仅 T3SS 效应物，而且 T5SS 蛋白也可以被认为是“细胞骨架毒素”，它们导致宿主细胞细胞骨架动力学的深刻改变，并导致致病结果。
