CD44 binds to the Shigella IpaB protein and participates in bacterial invasion of epithelial cells
CD44 binds to the Shigella IpaB protein and participates in bacterial invasion of epithelial cells
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DOI：
10.1046/j.1462-5822.2000.00028.x
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发表时间：
2000-02
影响因子：
3.4
通讯作者：
A. Skoudy;J. Mounier;A. Aruffo;H. Ohayon;P. Gounon;P. Sansonetti;G. Tran Van Nhieu
中科院分区：
文献类型：
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作者：
A. Skoudy;J. Mounier;A. Aruffo;H. Ohayon;P. Gounon;P. Sansonetti;G. Tran Van Nhieu
志贺氏菌进入上皮细胞的特征在于在细菌与细胞膜相互作用的位点处宿主细胞骨架的瞬时重组，这导致细菌在巨胞饮过程中被吞噬。使用HeLa细胞提取物的亲和层析，我们在这里显示，透明质酸受体CD 44与IpaB，一种志贺氏菌蛋白，分泌细胞接触。重叠和固相分析表明，IpaB直接与CD 44的细胞外结构域结合;结合是可饱和和可重复的，半最大抑制浓度为175 nM。免疫沉淀实验表明，IpaB与CD 44在志贺菌进入。CD 44在细菌进入位点募集，并定位于志贺氏菌诱导的细胞延伸的质膜上。用抗CD 44单克隆抗体预处理细胞导致志贺氏菌诱导的细胞骨架重组的抑制，以及细菌进入的抑制，而在缺乏CD 44的细胞中转染CD 44导致细菌与细胞的结合和内化增加。IpaB-CD 44相互作用似乎是志贺氏菌入侵所必需的，启动了进入过程的早期步骤。
Shigella entry into epithelial cells is characterized by a transient reorganization of the host cell cytoskeleton at the site of bacterial interaction with the cell membrane, which leads to bacterial engulfment in a macropinocytic process. Using affinity chromatography on HeLa cell extracts, we show here that the hyaluronan receptor CD44 associates with IpaB, a Shigella protein that is secreted upon cell contact. Overlay and solid‐phase assays indicated that IpaB binds directly to the extracellular domain of CD44; binding is saturable and inhibitable, with a half‐ maximal inhibitory concentration of 175 nM. Immunoprecipitation experiments showed that IpaB associates with CD44 during Shigella entry. CD44 is recruited at bacterial entry sites and localizes at the plasma membrane of cellular extensions induced by Shigella. Pretreatment of cells with an anti‐CD44 monoclonal antibody resulted in inhibition of Shigella‐induced cytoskeletal reorganization, as well as inhibition of bacterial entry, whereas transfection of CD44 in cells that are deficient for CD44 results in increased bacterial binding to cells and internalization. The IpaB–CD44 interaction appears to be required for Shigella invasion by initiating the early steps of the entry process.