The Intracellular Pathogen Response Triggers Defense Against Co-evolved Pathogens

细胞内病原体反应触发针对共同进化病原体的防御

基本信息

批准号：
10468643
负责人：
Emily R Troemel
金额：
$ 35.77万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-08-01 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10468643
关键词：
Address Animal Model Animals Biochemical Caenorhabditis elegans Cells Co-Immunoprecipitations Communicable Diseases Crohn&apos s disease Cryoelectron Microscopy Development Diarrhea Disease Epithelial Epithelial Cells Gene Expression Gene Family Genes Genetic Screening Genetic Transcription Genetic study Goals Health Human Immune Immune response Immunity Infection Infection Control Inflammatory Inflammatory Bowel Diseases Integration Host Factors Invaded Knowledge Lead Learning Methods Microbe Microsporidia Mission Molecular Structure Mus Mutation Names Nematoda Operon Organism Outcome Parasites Pathway interactions Phenotype Physiological Play Pneumonia Process Proteins Public Health RNA Interference Recombinants Research Resistance Role Sequence Analysis Structure Study models System Time Tissues United States National Institutes of Health Viral Virulence Factors Virus Virus Diseases Work X-Ray Crystallography base biological adaptation to stress burden of illness enteric infection enteric pathogen fitness infectious disease treatment innovation insight intestinal epithelium loss of function mutation mutant novel paralogous gene pathogen prevent programs protein complex protein structure response stressor targeted treatment ubiquitin ligase virtual

项目摘要

Project Summary Infectious diseases impose a significant burden on human health, with epithelial cells on the front lines of attack by disease-causing microbes that can invade and replicate inside of these cells. In addition to diseases such as diarrhea and pneumonia caused by pathogens, inappropriate activation of defense pathways in epithelial cells can lead to inflammatory disease. Therefore, it is critical learn more about epithelial defense against intracellular pathogens. In particular, little is known about defense against the Microsporidia phylum of fungal-related intracellular parasites, 14 of which can infect and cause disease in humans, most commonly infecting intestinal epithelial cells. We have developed a convenient whole-animal model for studying defense against microsporidia through characterization of natural intestinal infection in the nematode C. elegans. Our long-term goal is to dissect the mechanisms by which epithelial cells defend against co-evolved intracellular pathogens like microsporidia. Closing this gap in our understanding will provide new insights for treating infectious disease and inflammatory disorders. Our central hypothesis is that attack from co-evolved pathogens causes expansion and diversification of host genes to become ‘species-specific’ although these genes may control conserved immune pathways. The objective here is to characterize the species-specific pals gene family, which expanded to 39 pals genes in C. elegans, whereas there is only one pals gene in humans. Virtually nothing is known about PALS protein structure or biochemical function in any system, although they have been connected to ubiquitin ligases through sequence analysis and genetic studies in C. elegans. We found PALS-22 and PALS-25 to be key regulators of a common transcriptional response to natural microsporidia and viral infections in C. elegans that we call the Intracellular Pathogen Response or IPR. The IPR appears to define an entire physiological program and our forward genetic screens identified PALS-22 as a negative regulator and PALS-25 as a positive regulator of the IPR. Loss of PALS-22 leads to enhanced immunity against intracellular pathogens, increased RNA interference, as well as fitness consequences such as delayed development, all of which depend on PALS-25. In Specific Aim 1 we will characterize the relationship between gene expression and immune responses regulated by PALS-22 and PALS-25, identify the tissues where they act, and define the stage of microsporidia they target. In Specific Aim 2 we will recombinantly express PALS-22 and PALS-25 proteins to characterize their interaction, as well as their structure using X-ray crystallography and cryo EM. In Specific Aim 3 we will analyze the role of other PALS proteins, RNAi machinery and identify new regulators of the IPR. The approach is innovative as it focuses on uncharacterized proteins that regulate a novel form of epithelial immunity. The proposed research is significant, because it could lead to new treatments for infectious diseases and inflammatory disorders.

项目摘要传染病对人类健康施加了重大燃烧，前线上皮细胞可以在这些细胞内部侵入和复制的引起疾病的微生物发作。此外病原体引起的腹泻和肺炎等疾病，防御途径不适当激活在上皮细胞中会导致炎症性疾病。因此，至关重要的是关于上皮防御的更多信息针对细胞内病原体。特别是，关于针对微孢子虫门的防御知之甚少与真菌相关的细胞内寄生虫，其中14个会感染并引起人类疾病，最常见感染肠上皮细胞。我们已经开发了一个方便的全动物模型来研究防御通过表征线虫秀丽隐杆线虫中天然肠道感染的特征，以对抗微孢子虫。我们的长期目标是剖析上皮细胞防御共同进化的细胞内的机制病原体如微孢子虫。在我们的理解中缩小这一差距将为治疗提供新的见解传染病和炎症性疾病。我们的中心假设是共同进化的病原体的攻击导致宿主基因的扩张和多样化成为“物种特异性”，尽管这些基因可能控制配置的免疫途径。这里的目的是表征规格特异性的PAL基因一家人在秀丽隐杆线虫中扩展到39个好朋友基因，而人类只有一个好朋友基因。实际上，关于任何系统中的PALS蛋白结构或生化功能，几乎一无所知，尽管它们通过秀丽隐杆线虫中的序列分析和遗传研究，已连接到泛素连接酶。我们发现PALS-22和PALS-25是对自然的共同转录响应的关键调节剂秀丽隐杆线虫中的微孢子虫和病毒感染，我们称为细胞内病原体反应或IPR。 IPR似乎定义了整个物理程序，而我们的正向遗传筛选将PALS-22确定为负调节器和PALS-25作为IPR的积极调节剂。 PAL-22的损失导致增强免疫对细胞内病原体的免疫力，RNA干扰增加以及适应性后果作为延迟的发展，所有这些都取决于PALS-25。在特定目标1中，我们将表征基因表达与由PALS-22和PALS-25调节的免疫反应之间的关系，鉴定它们作用的组织，并定义其靶向的微孢子虫的阶段。在特定目标2中，我们将重组表达PALS-22和PALS-25蛋白以表征它们的相互作用及其使用X射线晶体学和冷冻EM结构。在特定目标3中，我们将分析其他朋友的作用蛋白质，RNAi机械并确定知识产权的新调节剂。这种方法是创新的，因为它专注于调节上皮免疫的新形式的未表征的蛋白质。拟议的研究很重要，因为它可能导致有关传染病和炎症性疾病的新治疗方法。