Escherichia coli invasion of brain endothelial cells

大肠杆菌侵袭脑内皮细胞

• 批准号: 6768710
• 负责人: SHENG-HE HUANG
• 金额: $ 26.04万
• 依托单位: CHILDREN'S HOSPITAL OF LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6768710
• 关键词: Escherichia; coli; invasion; brain; endothelial

DESCRIPTION (provided by applicant): E. coli K1 is the most common gram-negative organism causing neonatal meningitis. One of the least understood issues in the pathogenesis of this disease is how circulating E. coli K1 crosses the blood-brain barrier (BBB) to cause brain injury. We have demonstrated in the in vitro and in vivo models of the BBB that E. coli K1 invasion is a complex process mediated by multiple E. coli invasion determinants, among which the 50-kDa protein encoded by ibeA is unique to E. coli K1. A bovine IbeA-binding protein (IbeABP) has been isolated by IbeA-affinity chromatography from brain microvascular endothelial cells (BMEC). The ibeA locus is a genetic island of meningitic E. coli (GimA) containing 15 genes, which consist of four operons, ptnlPKC, cglDTEC, gcxKRCI and ibeRAT. IbeA is an important virulence factor contributing to E. coli K1-mediated invasion in BMEC and the 14 other genes may involve in energy metabolism. The regulatory protein IbeR carrying an as4-interaction domain belongs to the NtrC/NifA family of transcriptional activators. It has been shown that anaerobic growth and glucose greatly enhanced E. coli K1 invasion of BMEC. Based on these results, we have hypothesized that the ibeA locus-mediated invasion and energy metabolism are coordinate events in pathogenesis of E. coli K1 meningitis. Interactions between IbeA and its receptor induce cellular responses that are required for E. coli entry of BMECs. Invasion gene expression is regulated by the genetic island GimA including IbeR and environmental signals. Our hypothesis will be tested through the following Specific Aims. (1). To examine how IbeA contributes to E. coil K1 entry of human BMECs. (2). To further characterize the role of IbeABP in E. coil K1 invasion of human BMEC. (3). To determine how E. coil K1 invasion gene expression is regulated by the ibeA locus (GimA) including IbeR and environmental signals (glucose and oxygen tension).

描述（由申请人提供）：大肠杆菌K1是导致新生儿脑膜炎的最常见的革兰氏阴性生物。 该疾病发病机理中最了解的问题之一是循环大肠杆菌K1如何越过血脑屏障（BBB）引起脑损伤。 我们已经在BBB的体外和体内模型中证明了大肠杆菌K1侵袭是由多个大肠杆菌浸润决定因素介导的复杂过程，其中由IBEA编码的50 kDa蛋白在大肠杆菌K1中是独有的。从脑微血管内皮细胞（BMEC）中，iBEA亲密色谱分离出牛IBEA结合蛋白（IBEABP）。 IBEA基因座是一个含15个基因的脑膜大肠杆菌（GIMA）的遗传岛，由四个操纵子组成，PTNLPKC，CGLDTEC，GCXKRCI和IBERAT。 IBEA是导致大肠杆菌K1介导的BMEC侵袭的重要毒力因子，其他14个基因可能涉及能量代谢。带有AS4相互作用域的调节蛋白Iber属于转录激活剂的NTRC/NIFA家族。已经表明，厌氧生长和葡萄糖大大增强了大肠杆菌K1的BMEC侵袭。基于这些结果，我们假设IBEA基因座介导的侵袭和能量代谢是大肠杆菌K1脑膜炎发病机理中的坐标事件。 IBEA及其受体之间的相互作用引起了BMEC大肠杆菌进入所需的细胞反应。入侵基因表达受到遗传岛GIMA的调节，包括iber和环境信号。我们的假设将通过以下特定目的进行检验。 （1）。检查伊比亚如何为人类BMEC的E. coil K1进入。 （2）。为了进一步表征IBEABP在E. coil K1入侵人BMEC中的作用。 （3）。为了确定E. coil K1侵袭基因表达如何受到IBEA基因座（GIMA）的调节，包括IBER和环境信号（葡萄糖和氧张力）。