Systematic Genetic Analysis of C. albicans CNS Infection

白色念珠菌中枢神经系统感染的系统遗传分析

基本信息

批准号：
10666122
负责人：
Damian J Krysan
金额：
$ 20.93万
依托单位：
UNIVERSITY OF IOWA
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-02-01 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10666122
关键词：
Address Adopted Adult Affect Aspergillus Bacteria Bacterial Infections Bar Codes Biological Assay Brain Candida Candida albicans Candidiasis Cell Communication Central Nervous System Central Nervous System Diseases Central Nervous System Infections Cessation of life Clinical Coccidioides Collection Cryptococcus Development Disease Disseminated candidiasis Environment Eye Future Gastrointestinal tract structure Genes Genetic Genetic Screening Genetic Transcription Goals Grant Histoplasma Human Immune response Immunosuppression Individual Infant Infection Interleukin-1 Interleukin-1 Receptors Intravenous Kidney Knowledge Libraries Liver Lung Mediating Meningoencephalitis Modeling Mouse Strains Mus Mutation Neurotropism Oral cavity Organ Organism Pathogenesis Patients Persons Pregnancy Premature Infant Protein Kinase Research Risk Role Route Sepsis Site Spleen Standard Model Survivors Technology Virulence Wild Type Mouse Work age group body system brain endothelial cell brain tissue clinically relevant cohort congenic experimental study fitness fungus genetic analysis high risk immune function in vivo infant infection infant outcome innate immune pathways mouse model mutant nano-string neurodevelopment novel oropharyngeal thrush pathogen pathogenic fungus prevent response transcription factor

项目摘要

PROJECT SUMMARY The central nervous system (CNS) is an important target organ for nearly every major human fungal pathogen including Cryptococcus, Coccidioides, Candida, Aspergillus, Histoplasma and others. In almost all examples, the fungus either colonizes or infects one organ system and then disseminates to the CNS. The most common initial site of infection is the lung as exemplified by the pathogenesis of Cryptococcus, Histoplasma, Coccidioides, and Aspergillus while Candida albicans is unique in that it is a commensal of the human GI tract that infects in the brain during invasive disease. Premature infants have long been recognized as the patient cohort most at-risk for C. albicans CNS disease, although recently it has been recognized that adults with mutations in the CARD9 innate immune pathway are also at high risk. Importantly, C. albicans meningoencephalitis contributes to the fact that, among infants who survive sepsis, those infected with C. albicans have much poorer neurodevelopmental outcomes than infants infected with bacteria. Thus, CNS disease is a clinically important sequelae of candidiasis. However, we know very little about the mechanisms that underlie the ability of C. albicans to infect the CNS. To address this gap in knowledge, we propose to utilize a new model of C. albicans CNS infection to screen collections of transcription factor (TF) and protein kinase (PK) mutants to identify key regulators of C. albicans neurotropism. We discovered that mice lacking the IL-1 receptor (IL1-R) develop dramatically increased brain burden during disseminated candidiasis relative to congenic WT mice. The increased CNS fungal burden in il1r-/- mice provides sufficiently robust dynamic range to allow the identification of C. albicans mutants with decreased CNS infectivity whereas standard WT mouse strains are only transiently infected by C. albicans at relatively low fungal burden. We, therefore, propose to use this novel model to perform a genetic screen to identify TFs and PKs that are required for C. albicans CNS infectivity (Aim 1). We will generate competitive fitness profiles of barcoded pools of TF mutants isolated from mouse brain tissue after both intravenous (IV) and intracranial (IC) inoculation routes. In Aim 2, we will characterize the effects of a focused set of TF and PK mutants by: 1) analyzing their interactions with on brain endothelial cells; 2) determining their effect on the transcription of virulence and environmentally responsive genes in vivo during CNS infection; and 3) determining their genetic interaction profiles with the other TFs and PKs. These experiments will provide the first characterization of the genetic and transcriptional requirements for C. albicans CNS infection and will set the stage for future, detailed mechanistic studies of C. albicans neurotropism.

项目概要中枢神经系统（CNS）是几乎所有主要人类真菌的重要靶器官病原菌包括隐球菌属、球孢子菌属、念珠菌属、曲霉属、组织胞浆菌属等。几乎在所有例如，真菌定殖或感染一个器官系统，然后传播到中枢神经系统。这最常见的初始感染部位是肺部，隐球菌的发病机制就是例证，组织胞浆菌、球孢子菌和曲霉属，而白色念珠菌的独特之处在于它是在侵袭性疾病期间感染大脑的人类胃肠道。早产儿早已被人们所认识作为最容易患白色念珠菌 CNS 疾病的患者群体，尽管最近人们认识到 CARD9 先天免疫通路突变的成年人也处于高风险之中。重要的是，白色念珠菌脑膜脑炎导致了这样一个事实：在败血症中幸存的婴儿中，那些感染了念珠菌的婴儿。白色念珠菌的神经发育结果比感染细菌的婴儿差得多。因此，中枢神经系统该病是临床上重要的念珠菌病后遗症。然而我们对其机制知之甚少这是白色念珠菌感染中枢神经系统能力的基础。为了解决这一知识差距，我们建议利用白色念珠菌 CNS 感染的新模型来筛选转录因子 (TF) 和蛋白质的集合激酶 (PK) 突变体可识别白色念珠菌向神经性的关键调节因子。我们发现小鼠缺乏 IL-1受体（IL1-R）在播散性念珠菌病期间显着增加大脑负担至同系野生型小鼠。 il1r-/- 小鼠中枢神经系统真菌负担的增加提供了足够强大的动态范围允许识别 CNS 感染性降低的白色念珠菌突变体，而标准 WT 小鼠品系仅在真菌负荷相对较低的情况下被白色念珠菌短暂感染。因此，我们建议使用这种新颖的模型进行遗传筛选，以识别 C. 所需的 TF 和 PK。白色念珠菌中枢神经系统感染性（目标 1）。我们将为 TF 突变体条形码池生成有竞争力的适应度概况通过静脉内 (IV) 和颅内 (IC) 接种途径从小鼠脑组织中分离出来。在目标 2 中，我们将通过以下方式描述一组重点 TF 和 PK 突变体的影响：1) 分析它们与对脑内皮细胞； 2) 确定它们对毒力和环境转录的影响中枢神经系统感染期间体内的反应基因； 3）确定它们与其他 TF 和 PK。这些实验将提供遗传和转录的第一个表征白色念珠菌中枢神经系统感染的要求，并将为未来详细的白色念珠菌机制研究奠定基础。白色念珠菌趋神经性。