Cytolethal Distending Toxin and Intestinal Homeostasis

细胞致死膨胀毒素和肠道稳态

基本信息

批准号：
10371246
负责人：
Steven R. Blanke
金额：
$ 22.06万
依托单位：
UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-03-12 至 2024-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10371246
关键词：
Address Architecture Autoimmune Diseases Bacteria Biology Blood Blood Circulation Campylobacter jejuni Cell Death Cell Differentiation process Cell Line Cell Proliferation Cells Characteristics Clinical Cytotoxin DNA DNA Damage DNA Repair Data Diabetes Mellitus Disease Epithelial Epithelial Cells Family Functional disorder Gastrointestinal tract structure Goals Health Human Human Pathology In Vitro Individual Infection Inflammatory Bowel Diseases Inflammatory Response Inhibition of Cell Proliferation Intestines Knowledge Laboratories Lamina Propria Liver Mediating Membrane Metabolic Diseases Microbe Modeling Multiple Sclerosis Mus Mutagens Natural regeneration Obesity Oral cavity Organoids Pathogenesis Permeability Physiological Play Proliferating Proteobacteria Reporting Research Rheumatoid Arthritis Risk Factors Role Site Spleen Stomach Structure Testing Tissues Toxin Villus Virus alpha Toxin base cell immortalization crypt cell cytolethal distending toxin cytotoxic cytotoxicity dysbiosis enteric infection enteric pathogen experimental study fungus genotoxicity gut microbiota host-microbe interactions human disease in vivo insight interest intestinal barrier intestinal crypt intestinal epithelium intestinal homeostasis intestinal villi microbial microbial colonization pathogen pathogenic bacteria pathogenic virus reproductive tract response stem stem cells transcription factor

项目摘要

Our long-term goal is to understand how pathogen-mediated genotoxicity, which is increasingly associated with pathogenic bacteria, fungi, and viruses, impacts microbe-host interactions and disease pathogenesis. We are studying the cytolethal distending toxins (CDTs), a conserved, but broadly distributed family of intracellular- acting genotoxins, which are secreted by pathogenic bacteria that infect and damage mucocutaneous tissues at different sites within the body, including the gastrointestinal tract. Despite increasing evidence of the importance of CDTs as determinants of pathogenesis, a major deficit in our understanding of CDT biology is the exact role of these genotoxins during infection. In this application, we propose studies to address the impact of genotoxicity at the intestine mediated by CDT produced by the human intestinal pathogen Campylobacter jejuni (Cj-CDT), which has been demonstrated to be important for C. jejuni (Cj) invasion of the epithelial barrier, and subsequent dissemination to the blood, spleen and liver in mice. Although the mechanism of invasion is poorly understood, Cj-CDT-mediated cytotoxicity, which has been examined primarily in vitro using immortalized cell lines, is widely believed to be a major driver of damage to the epithelial barrier during infection. However, preliminary studies in our lab revealed that Cj-CDT alters epithelial barrier integrity and function, in the absence of toxin-mediated cell death, within a murine-derived intestinal organoid model that recapitulates the dynamic regeneration of the crypt/villus architecture of the intestinal epithelium. These findings challenge the importance of Cj-CDT cytotoxicity as a mechanism of toxin-dependent changes at epithelial barriers, by suggesting possible associations between Cj-CDT-mediated DNA damage and/or host DNA damage repair and the mechanisms that regulate cell proliferation and differentiation during normal regeneration of the intestinal epithelium every 3-5 days. Based on preliminary data from our laboratory, our overall model of this potential association is that Cj- CDT-dependent DNA damage and subsequent DNA damage response (DDR) promote intestinal barrier dysfunction by modulating cell proliferation and cellular lineage allocation, both of which are critical for regeneration. In this exploratory R21 application, we address several existing gaps in knowledge. In Aim 1, we propose studies to test predictions of the hypothesis that Cj-CDT-dependent genotoxicity is causal for intestinal barrier dysfunction. We will investigate the causal relationship between Cj-CDT-dependent DNA damage/repair and alterations in cellular proliferation and differentiation, and assess the essentiality of Cj-CDT for inducing epithelial barrier function during Cj infection of intestinal organoids. In Aim 2, we will investigate the relationship between Cj-CDT-dependent DNA damage/repair, and the reduction in cellular levels of SNAI1, an important transcriptional factor involved in regulating intestinal lineage allocation. Because subversion of epithelial barrier integrity is associated with human disease and pathology, we are ultimately interested in extending these studies to investigate the potential negative impact of Cj-CDT-mediated genotoxicity on human intestinal health.

我们的长期目标是了解病原体介导的遗传毒性如何越来越多地与致病细菌，真菌和病毒会影响微生物宿主相互作用和疾病发病机理。我们是研究细胞降低的毒素（CDTS），一种保守但分布广泛的细胞内 - 作用基因毒素，由致病细菌分泌，这些细菌感染并损害粘膜皮组织体内的不同部位，包括胃肠道。尽管有越来越重要的证据 CDT作为发病机理的决定因素，我们对CDT生物学的理解的主要缺陷是确切的作用这些在感染过程中的基因毒素。在此应用中，我们提出研究以解决遗传毒性的影响在由人类病原体弯曲杆菌（CJ-CDT）产生的CDT介导的肠道上，事实证明，这对于jejuni（CJ）的上皮屏障至关重要，随后在小鼠中传播到血液，脾脏和肝脏。尽管入侵机制的理解很少，但 CJ-CDT介导的细胞毒性主要使用永生细胞系在体外进行了研究，广泛是被认为是感染期间上皮屏障的主要驱动力。但是，我们的实验室表明，在没有毒素介导的细胞的情况下，CJ-CDT改变了上皮屏障完整性和功能死亡，在鼠源的肠道器官模型中，该模型概括了动态再生肠上皮的地穴/绒毛建筑。这些发现挑战了CJ-CDT的重要性细胞毒性作为上皮屏障的毒素依赖性变化的机制 CJ-CDT介导的DNA损伤与/或宿主DNA损伤修复与机制之间的关联每3-5每3-5调节肠上皮的正常再生过程中的细胞增殖和分化天。基于我们实验室的初步数据，我们对这种潜在关联的总体模型是CJ- 依赖CDT的DNA损伤和随后的DNA损伤响应（DDR）促进肠屏障通过调节细胞增殖和细胞谱系分配的功能障碍，这两者都至关重要再生。在此探索性R21应用程序中，我们解决了知识上的几个现有差距。在AIM 1中，我们提出的研究以检验预测CJ-CDT依赖性遗传毒性的假设是肠道的。障碍障碍。我们将研究CJ-CDT依赖性DNA损伤/修复之间的因果关系以及细胞增殖和分化的改变，并评估CJ-CDT诱导的重要性 CJ感染肠道器官的上皮屏障功能。在AIM 2中，我们将调查关系在CJ-CDT依赖性DNA损伤/修复和SNAI1的细胞水平降低之间转录因子涉及调节肠道谱系分配。因为上皮屏障完整性与人类疾病和病理有关，我们最终有兴趣将其扩展研究CJ-CDT介导的遗传毒性对人类肠道健康的潜在负面影响。