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.

项目摘要中枢神经系统（CNS）是几乎每个主要人类真菌的重要目标器官病原体，包括隐孢子，球虫，念珠菌，曲霉，组织浮肿等。几乎全部例子，真菌可以定植或感染一个器官系统，然后将其传播到中枢神经系统中。这最常见的初始感染部位是肺部，例如加密环球的发病机理的例证组织质量，球虫剂和曲霉，而白色念珠菌的独特之处在于它是共同的人类胃肠道在侵入性疾病期间会在大脑中感染。早期婴儿长期以来一直被认可作为患者队列最高危的白色念珠菌中枢神经系统疾病，尽管最近已经认识到 Card9先天免疫途径中有突变的成年人也有高风险。重要的是，白色念珠菌脑膜脑炎有助于以下事实：在幸存的败血症的婴儿中，感染了C. 与感染细菌的婴儿相比，白色唱片的神经发育结局差得多。因此，CNS 疾病是临床上重要的念珠菌病的后遗症。但是，我们对机制知之甚少这是白色念珠菌感染中枢神经系统的能力的基础。为了解决知识的这一差距，我们建议利用新的白色念珠菌中枢神经系统感染的新模型来筛选转录因子（TF）和蛋白质的收集激酶（PK）突变体以鉴定白色念珠菌神经性的关键调节剂。我们发现小鼠缺乏 IL-1受体（IL1-R）在传播的念珠菌病相对期间大脑负担显着增加到先天的wt小鼠。 IL1R - / - 小鼠中的CNS真菌负担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 小鼠菌株仅在相对较低的真菌负担下被白色念珠菌瞬时感染。因此，我们建议使用这种新型模型执行遗传筛选，以识别C。白色唱片中枢神经系统感染性（AIM 1）。我们将生成TF突变体的条形码池的竞争性健身曲线静脉内（IV）和颅内（IC）接种途径后，从小鼠脑组织中分离出来。在AIM 2中，我们将通过：1）分析其与在脑内皮细胞上； 2）确定它们对毒力转录和环境的影响 CNS感染期间体内反应性基因； 3）确定其遗传相互作用曲线与其他TF和PK。这些实验将提供遗传和转录的首次表征白色念珠菌CNS感染的要求，并将为C.的未来详细的机械研究奠定基础。白色念珠菌神经性。