• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Investigation of the intracellular lifecycle of uropathogenic Escherichia coli.
【24h】

Investigation of the intracellular lifecycle of uropathogenic Escherichia coli.

机译：尿路致病性大肠杆菌的细胞内生命周期研究。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Uropathogenic E. coli (UPEC) cause most community-acquired and nosocomial urinary tract infections (UTI). In a mouse model of UTI, UPEC invade superficial bladder cells and proliferate rapidly, forming biofilm-like structures called intracellular bacterial communities (IBC). Using a gentamicin protection assay and fluorescence microscopy, I have developed an in vitro model for studying UPEC invasion and proliferation within immortalized human urothelial cells. By pharmacologic manipulation and RNA interference, a number of host proteins were identified that are involved in E. coli invasion of urothelial cells. Using isogenic mutants, bacterial components FimH and lipopolysaccharide (LPS) were demonstrated to play a role in E. coli invasion. These studies showed that E. coli invades urothelial cells by multiple mechanisms, and that UPEC and K-12 E. coli invade by different mechanisms. UPEC, but not K-12 E. coli, engaged in beta1 integrin-dependent adherence and invasion. Additionally, UPEC strains with rough-LPS were more invasive than strains with smooth LPS in a TLR4-dependent manner. UPEC proliferated within urothelial cells, while K-12 strains could not. Intracellular proliferation was dependent on the expression of full length LPS, and proliferating UPEC were eradicated by exposure to lysosomotropic drugs chloroquine or propranolol. This in vitro model is a valuable tool for identifying host and bacterial components required for urothelial invasion and intracellular proliferation by UPEC, and for facilitating the identification of potential treatments for UTI.;Pre-incubation of urothelial cells with the cholesterol-sequestering drug filipin resulted in increased numbers of intracellular UPEC relative to untreated cultures. Upon inspection by fluorescence microscopy, filipin-treated cultures exhibited large, dense bacterial aggregates within cells that resembled IBC. In vitro IBC required that the urothelial cells, but not the bacteria, be filipin-treated prior to infection. IBC-like structures were morphologically indistinguishable from, and shared many characteristics with IBC in the murine model of UTI. These characteristics include the kinetics of formation, the expression of antigen 43, a requirement for fimH , and the up-regulation of iron acquisition systems. Thus, immortalized urothelial cultures that recapitulate IBC formation in vitro represent a novel system for the molecular and biochemical characterization of the UPEC intracellular life cycle.
机译：致病性大肠杆菌（UPEC）导致大多数社区获得性和医院内尿路感染（UTI）。在尿路感染的小鼠模型中，UPEC侵入浅表膀胱细胞并迅速增殖，形成称为细胞内细菌群落（IBC）的生物膜样结构。使用庆大霉素保护分析和荧光显微镜，我开发了一种体外模型，用于研究永生化的人尿道上皮细胞中UPEC的侵袭和增殖。通过药理学操作和RNA干扰，鉴定了许多宿主蛋白，它们参与大肠杆菌对尿道上皮细胞的侵袭。使用等基因突变体，细菌成分FimH和脂多糖（LPS）被证明在大肠杆菌入侵中起作用。这些研究表明，大肠杆菌通过多种机制入侵尿路上皮细胞，而UPEC和K-12大肠杆菌则通过不同的机制入侵。 UPEC，而不是K-12大肠杆菌，参与beta1整合素依赖性粘附和侵袭。此外，以TLR4依赖性的方式，具有粗糙LPS的UPEC菌株比具有光滑LPS的菌株更具侵入性。 UPEC在尿道上皮细胞中增殖，而K-12菌株则不能。细胞内增殖取决于全长LPS的表达，并且通过暴露于溶溶同性药物氯喹或普萘洛尔可消除增殖的UPEC。该体外模型是鉴定UPEC尿路上皮侵袭和细胞内增殖所需的宿主和细菌成分，并有助于确定UTI潜在治疗方法的有价值的工具;尿嘧啶上皮细胞与胆固醇替代药物菲林的预孵育与未经处理的培养物相比，细胞内UPEC的数量增加。通过荧光显微镜检查，用菲律宾血脂处理的培养物在类似于IBC的细胞内显示出大而致密的细菌聚集体。体外IBC要求在感染前对尿道上皮细胞（而不是细菌）进行尿素处理。在UTI鼠模型中，类IBC的结构与IBC的形态没有区别，并具有许多特征。这些特征包括形成动力学，抗原43的表达，fimH的需要以及铁捕获系统的上调。因此，永生的尿路上皮培养物在体外概括了IBC的形成代表了用于UPEC细胞内生命周期的分子和生化表征的新系统。

著录项

  • 作者

    Berry, Ruth Emrick.;

  • 作者单位

    Northwestern University.;

  • 授予单位 Northwestern University.;
  • 学科 Biology Cell.;Biology Microbiology.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 293 p.
  • 总页数 293
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

  • 入库时间 2022-08-17 11:38:26

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号