IPAB OF SHIGELLA-FLEXNERI CAUSES ENTRY INTO EPITHELIAL-CELLS AND ESCAPE FROM THE PHAGOCYTIC VACUOLE
IPAB OF SHIGELLA-FLEXNERI CAUSES ENTRY INTO EPITHELIAL-CELLS AND ESCAPE FROM THE PHAGOCYTIC VACUOLE
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DOI：
10.1002/j.1460-2075.1992.tb05253.x
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发表时间：
1992-05-01
期刊：
影响因子：
11.4
通讯作者：
SANSONETTI, PJ
中科院分区：
文献类型：
--
作者：
HIGH, N;MOUNIER, J;SANSONETTI, PJ
通过在福氏志贺菌ipaB基因内产生突变，我们已经证明上皮细胞的侵袭是一个三步过程，包括粘附在细胞表面上、吞噬空泡的进入和裂解，从而允许随后进入细胞质。已特别研究了缺乏IpaB表达但仍表达下游基因的插入突变体SC 403。它是非侵入性的，不引起肌动蛋白聚合，但结合HeLa细胞，表明粘附步骤发生在进入过程之前。使用巨噬细胞系J774研究了ipaB失活对福氏志贺菌细胞内行为的影响。SC 403不能溶解吞噬空泡，而且，该菌株不显示志贺氏菌的接触介导的溶血活性特征。除了作为入侵复合物的主要成分之外，IpaB还充当能够逃逸到细胞质区室的膜溶解毒素。
By creating mutations within the Shigella flexneri ipaB gene, we have demonstrated that the invasion of epithelial cells is a three-step process encompassing adhesion on the cell surface, entry and lysis of the phagocytic vacuole allowing subsequent access to the cytoplasm. SC403, an insertion mutant which lacks expression of IpaB but still expresses downstream genes, has been particularly studied. It is non-invasive, does not elicit actin polymerization, but binds to HeLa cells indicating that an adhesion step occurs immediately prior to the entry process. The consequence of the inactivation of ipaB on the intracellular behaviour of S.flexneri was investigated using the macrophage cell line J774. SC403 was unable to lyse the phagocytic vacuole; moreover, this strain did not display the contact mediated haemolytic activity characteristics of Shigella. In addition to being a major component of the invasion complex, IpaB acts as a membrane-lysing toxin enabling escape to the cytoplasmic compartment.