Salmonella enterica serotype Typhimurium MisL is an intestinal colonization factor that binds fibronectin
Salmonella enterica serotype Typhimurium MisL is an intestinal colonization factor that binds fibronectin
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DOI：
10.1111/j.1365-2958.2005.04666.x
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发表时间：
2005-07-01
影响因子：
3.6
通讯作者：
Bäumler, AJ
中科院分区：
文献类型：
--
作者：
Dorsey, CW;Laarakker, MC;Bäumler, AJ
MISL是沙门氏菌致病岛3(SPl3)编码的一种自身转运蛋白。为了探讨MISL在鼠伤寒沙门氏菌(S.typhimurium)致病机制中的作用，我们鉴定了MISL在小鼠感染过程中的功能，并确定了该粘附素的宿主受体。在鼠伤寒沙门氏菌肠道持续存在的模型中，一个MISL突变体的粪便数量明显低于野生型，其在盲肠内定植的能力受到了损害。以前的研究表明，细胞外基质蛋白的结合可能是鼠伤寒沙门氏菌肠道持久性的一个机制。构建了谷胱甘肽-S-转移酶(GST)MISL乘客区融合蛋白(GST-MISL(29-281))，用于研究其与细胞外基质蛋白的结合。在固相结合实验中，纯化的GST-MISL 29-281融合蛋白与纤维连接蛋白和IV型胶原结合，但不与I型胶原结合，在标准实验室条件下培养的鼠伤寒沙门氏菌中未检测到MISL表达。然而，当克隆的MISL基因在大肠杆菌阿拉伯糖启动子的驱动下表达时，通过Western印迹检测到MISL存在于鼠伤寒沙门氏菌外膜，通过流式细胞仪检测到MISL存在于细菌细胞表面。MISL的表达使鼠伤寒沙门氏菌能够将纤维连接蛋白结合到其细胞表面，导致附着到纤维连接蛋白涂层玻片上，并增加了MISL来源的人上皮细胞的侵袭力，因为MISL是一种参与肠道定植的细胞外基质粘附素。
MisL is an autotransporter protein encoded by Salmonella pathogenicity island 3 ( SPl3). To investigate the role of MisL in Salmonella enterica serotype Typhimurium ( S. Typhimurium) pathogenesis, we characterized its function during infection of mice and identified a host receptor for this adhesin. In a mouse model of S. Typhimurium intestinal persistence, a misL mutant was shed with the faeces in significantly lower numbers than the wild type and was impaired in its ability to colonize the cecum. Previous studies have implicated binding of extracellular matrix proteins as a possible mechanism for S. Typhimurium intestinal persistence. A gluthathione-S-transferase (GST) fusion protein to the MisL passenger domain (GST - MisL(29- 281)) was constructed to investigate binding to extracellular matrix proteins. In a solid-phase binding assay the purified GST - MisL 29-281 fusion protein bound to fibronectin and collagen IV, but not to collagen I. MisL expression was not detected by Western blot in S. Typhimurium grown under standard laboratory conditions. However, when expression of the cloned misL gene was driven by the Escherichia coli arabinose promoter, MisL could be detected in the S. Typhimurium outer membrane by Western blot and on the bacterial cell surface by flow cytometry. Expression of MisL enabled S. Typhimurium to bind fibronectin to its cell surface, resulting in attachment to fibronectin-coated glass slides and in increased invasiveness for human epithelial cells derived from MisL as an extracellular matrix adhesin involved in intestinal colonization.