Department of Veterinary Disease Biology, University Copenhagen, Stigbøjlen 4, DK-1870 Frederiksberg C, Denmark.
Gut Pathog. 2011 Sep 22;3:13. doi: 10.1186/1757-4749-3-13.
Acute gastroenteritis caused by the food-borne pathogen Campylobacter jejuni is associated with attachment of bacteria to the intestinal epithelium and subsequent invasion of epithelial cells. In C. jejuni, the periplasmic protein HtrA is required for efficient binding to epithelial cells. HtrA has both protease and chaperone activity, and is important for virulence of several bacterial pathogens.
The aim of this study was to determine the role of the dual activities of HtrA in host cell interaction of C. jejuni by comparing an htrA mutant lacking protease activity, but retaining chaperone activity, with a ΔhtrA mutant and the wild type strain. Binding of C. jejuni to both epithelial cells and macrophages was facilitated mainly by HtrA chaperone activity that may be involved in folding of outer membrane adhesins. In contrast, HtrA protease activity played only a minor role in interaction with host cells.
We show that HtrA protease and chaperone activities contribute differently to C. jejuni's interaction with mammalian host cells, with the chaperone activity playing the major role in host cell binding.
由食源性病原体空肠弯曲菌引起的急性肠胃炎与细菌附着在肠上皮和随后侵入上皮细胞有关。在空肠弯曲菌中，周质蛋白 HtrA 是与上皮细胞有效结合所必需的。HtrA 具有蛋白酶和伴侣活性，对几种细菌病原体的毒力很重要。
本研究旨在通过比较缺乏蛋白酶活性但保留伴侣活性的 htrA 突变体与 ΔhtrA 突变体和野生型菌株，确定 HtrA 的双重活性在空肠弯曲菌与宿主细胞相互作用中的作用。空肠弯曲菌与上皮细胞和巨噬细胞的结合主要通过 HtrA 伴侣活性促进，这可能涉及到外膜黏附素的折叠。相比之下，HtrA 蛋白酶活性在与宿主细胞的相互作用中只起次要作用。
我们表明，HtrA 蛋白酶和伴侣活性对空肠弯曲菌与哺乳动物宿主细胞的相互作用有不同的贡献，伴侣活性在宿主细胞结合中起主要作用。
