The molecular basis for the translocation of fungi from blood-to-brain.

真菌从血液转移到大脑的分子基础。

• 批准号: 10330006
• 负责人: ANGIE GELLI
• 金额: $ 36.12万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-15 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10330006
• 关键词: Acquired Immunodeficiency Syndrome; Acute; Area; Aspergillus; Autopsy; Binding; Blood; Brain; Brain Injuries; CD44 gene; Candida albicans; Cause of Death; Cells; Central Nervous System Agents; Central Nervous System Fungal Infections; Central Nervous System Infections; Cessation of life; Chronic; Coccidioides; Columbidae; Complex; Cryptococcus; Cryptococcus neoformans; Cryptococcus neoformans infection; Cystic Lesion; Cytoskeleton; Data; Development; Disease; Drops; Elements; Endocytosis; Endothelium; Environment; Fungal Spores; Goals; Health; Histoplasma capsulatum; Hospitalization; Human; In Vitro; Infection; Inhalation; Knock-out; Knowledge; Label; Lead; Mediating; Meningoencephalitis; Mission; Modeling; Molecular; Morbidity - disease rate; Movement; Mucor; Nature; Neuraxis; Pathogenesis; Pathologic; Pathway interactions; Patients; Permeability; Pharmaceutical Preparations; Process; Proliferating; Publishing; Receptor Protein-Tyrosine Kinases; Regulation; Reporting; Reproduction spores; Research; Risk; Role; Route; Series; Signal Transduction; Soil; Structure of parenchyma of lung; Technology; Testing; Time; Transactivation; Trees; United States National Institutes of Health; Work; aerosolized; blood-brain barrier crossing; blood-brain barrier permeabilization; brain endothelial cell; design; experimental study; fungus; improved; in vivo; innovation; migration; mortality; mouse model; neurotropic; novel strategies; novel therapeutics; pathogen; pathogenic fungus; prevent; prophylactic; recruit; response; spatiotemporal; trafficking

PROJECT ABSTRACT Infections of the central nervous system (CNS) caused by fungi have the highest morbidity and mortality when compared to other causative agents of CNS infections. Cryptococcus neoformans (Cn), Candida albicans, Aspergillus spp., Mucor, Coccidioides spp., and Histoplasma capsulatum are the most common cause of fungal brain infections resulting in a chronic instead of an acute or subacute meningoencephalitis. The long-term goal will investigate the spatio-temporal organization and molecular basis of Cn trafficking across the BBB and investigate a cross-talk between a transcellular mechanism and the opening of a paracellular path in response to Cn infection. Given our preliminary data and published studies, we propose that Cn represents an excellent model pathogen with which to determine the mechanisms that pathogenic fungi use to breach the BBB and enter the CNS. In our efforts to understand the molecular basis mediating the Cn-brain endothelium interactions, we identified a tyrosine kinase receptor (EphA2-TKR) as the central player. The central hypothesis states that fungal cells penetrate the BBB by engaging EphA2-TKR in order to access a binary path into the CNS. To test our hypothesis, we will investigate the interplay between fungal cells, EphA2-TRK and its downstream signaling components in mediating the translocation of Cn from blood-to-brain. The following specific aims will test the hypothesis: SA1 will investigate a Cn-induced CD44-mediated transactivation of EphA2-TKR activity and the interactome of EphA2-TKR. SA2 will examine the role of EphA2-TKR in upregulating vesicular traffic of Cn and resolve whether Cn-induced activity of EphA2-TKR promotes a co-regulation of a transcellular and paracellular pathway. SA3 will resolve the contribution of EphA2-TKR activity to the translocation of Cn from blood-to-brain in vivo and examine the molecular basis of changes in the permeability of the BBB when challenged by Cn. The proposed research is innovative because it will for the first time, detail the key players that promote the internalization and trafficking of fungi across the BBB. The innovation extends to our published studies that identified EphA2-TKR in the brain endothelium as a central element in mediating the migration Cn from blood-to-brain. This along with the notion that crossing of the BBB is initiated by a fungal-induced CD44-transactivation of EphA2-TKR to trigger a pathological use of endocytosis (and possibly a secondary paracellular path) in brain endothelial cells is a paradigm shift from our current understanding. We have proposed experiments that will use multiple complementary approaches to tease apart the molecular interaction between Cn, EphA2- TKR and CD44 while also using proximity-dependent labeling to identify the interactome of EphA2-TKR. The knowledge gained from our studies will make a significant contribution to fungal pathogenesis of the CNS, because it remains significantly understudied, and this work will spearhead the development of molecules that could block fungal entry and thus serve as pre- emptive or prophylactic therapy in patients at risk for developing fungal meningoencephalitis.

项目摘要 由真菌引起的中枢神经系统（CNS）感染的发病率最高，并且 与中枢神经系统感染的其他病因相比，死亡率。加密赛车 （CN），白色念珠菌，曲霉属，粘液，球虫属和组织囊肿 是真菌脑感染的最常见原因，导致慢性而不是急性 或亚急性脑膜脑炎。长期目标将调查时空 CN贩运跨BBB的组织和分子基础并调查了交叉对话 在跨细胞机理和响应CN的旁细胞路径的打开之间 感染。鉴于我们的初步数据和已发表的研究，我们建议CN代表 出色的模型病原体，以确定致病真菌使用的机制 违反BBB并进入中枢神经系统。在我们了解分子基础介导的努力中 CN-脑内皮相互作用，我们将酪氨酸激酶受体（Epha2-TKR）确定为 中心人。中央假设指出，真菌细胞通过参与来穿透BBB EPHA2-TKR为了访问CNS的二进制路径。为了检验我们的假设，我们将 研究真菌细胞，epha2-trk及其下游信号之间的相互作用 从血到脑介导CN易位的成分。以下特定目标 将检验假设：SA1将研究CN诱导的CD44介导的反式激活 EPHA2-TKR活性和Epha2-TKR的相互作用组。 SA2将检查EPHA2-TKR的作用 在上调CN的囊泡流量并解决CN诱导的EPHA2-TKR的活动是否 促进跨细胞和细胞细胞途径的共同调节。 SA3将解决 Epha2-TKR活性对CN从体内血统和脑的易位的贡献 在受到CN挑战时，检查BBB渗透性变化的分子基础。 拟议的研究具有创新性，因为它将首次详细介绍关键参与者 促进真菌在整个BBB中的内在化和贩运。创新扩展到我们 已发表的研究确定脑内皮中的Epha2-TKR是 从血到脑介导迁移CN。这与越过 BBB是由Epha2-TKR的真菌诱导的CD44-转移引发的，以触发病理 在脑内皮细胞中使用内吞作用（可能是次要细胞细胞路径）是 范式从我们目前的理解转移。我们提出了将使用的实验 多种互补的方法来分开CN，Epha2-之间的分子相互作用 TKR和CD44同时还使用接近性依赖性标记来识别 epha2-tkr。从我们的研究中获得的知识将为真菌做出重大贡献 中枢神经系统的发病机理，因为它仍然显着研究，这项工作将 带领可以阻止真菌进入的分子的发展，从而成为预先的 在患有真菌脑膜脑炎风险的患者中空虚或预防治疗。