Identifying human neuron IFN-γ dependent anti-Toxoplasma gondii responses

识别人类神经元 IFN-γ 依赖性抗弓形虫反应

• 批准号: 10619781
• 负责人: Jared Churko
• 金额: $ 19.19万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-12 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10619781
• 关键词: Acquired Immunodeficiency Syndrome; Acute; Address; Affect; Antiparasitic Agents; Antiviral Therapy; Astrocytes; Benign; Brain; CRISPR interference; Cells; Central Nervous System Infections; Cessation of life; Chronic; Clinical; Cognition; Cyst; Data; Development; Disease; DsRed; Engineering; Focal Neurologic Deficits; Foundations; Genetic; Genetic Recombination; Goals; Grant; HIV; HIV/AIDS; Human; Immune Evasion; Immune response; In Vitro; Infection; Interferon Type II; Invaded; Lesion; Mediating; Modeling; Molecular; Mus; Neurologic; Neurologic Deficit; Neurons; Outcome; Parasites; Pathogenesis; Pathway interactions; Patients; Persons; Phase; Population; Populations at Risk; Proteins; Protocols documentation; Reporter; Role; STAT1 gene; Seizures; Survivors; Technology; Toxoplasma gondii; Toxoplasmosis; Work; antiretroviral therapy; cell type; chronic infection; co-infection; cognitive function; curative treatments; cytokine; high reward; high risk; human pluripotent stem cell; in vivo; infection rate; knock-down; latent infection; mouse model; prevent; programs; response; stem cell biology; stem cells; tool; toxoplasmic encephalitis

Project Summary: Toxoplasma gondii is an intracellular parasite that latently infects many hosts, including humans. Successful latent infection requires T. gondii to evade cytokine-induced, cell intrinsic responses and switch from a fast-growing form to a slow-growing encysted form. In humans, this life-long infection occurs in the brain where T. gondii can reactivate in the setting of acquired immune deficiencies. In AIDS patients, toxoplasmic encephalitis is the most common cause of focal brain lesions and can cause prolonged neurologic deficits even after appropriate treatment. Recent studies also suggest that, even in HIV+ patients on effective antiretroviral therapy, persistent T. gondii infection may adversely affect cognition and global immune responses. Despite its clinical importance, we lack a mechanistic understanding of what is actually responsible for T. gondii’s pathogenesis in the CNS, including what enables long-term latent infection. Such understanding is crucial to eventually preventing symptomatic disease in HIV/AIDs patients. Within the CNS, cysts are primarily found in neurons. Based on limited in vitro and in vivo studies, it has been presumed that while infected astrocytes cleared intracellular parasites, neurons did not and thus were the de facto host cell for persistent infection. In the last decade, our pioneering work has questioned this model, including showing that IFN-γ-stimulated neurons mount anti-parasitic defenses. As most of this work has occurred in murine models and neurons, it will have missed human neuron-specific pathways (e.g., humans lack the terminal IFN-γ dependent proteins used by murine cells to kill intracellular parasites). The goal of this grant is to address this gap by establishing robust stem cell derived human neuron models (hPSC neurons) which can be used to mechanistically define human neuron-T. gondii interactions that enable immune evasion and persistence. To accomplish this goal, our will leverage our synergistic expertise in CNS toxoplasmosis (Dr. Koshy) and stem cell biology (Dr. Churko) to generate Cre reporter hPSC neurons and CRISPRi-expressing hPSC neurons (Aim 1) and to begin to define the mechanisms by which cytokine stimulated hPSC-neurons control T. gondii (Aim 2). With the completion of these aims, we will have established and validated tools that will form the essential foundation of a long-term program to molecularly define the neuron-T. gondii interactions that enable control and persistence of T. gondii in human neurons. The work proposed here represents an important first step toward developing human neuron-specific therapies for acute and chronic toxoplasmosis. Such therapies will be of great benefit for the HIV/AIDS population at risk for toxoplasmic encephalitis.

项目概要： 弓形虫是一种细胞内寄生虫，潜伏感染许多宿主，包括人类。 成功的潜伏感染需要弓形虫逃避细胞因子诱导的细胞内在反应和 从快速生长的形式转变为缓慢生长的包囊形式。对于人类来说，这种终生感染 发生在大脑中，在获得性免疫缺陷的情况下，弓形虫可以在大脑中重新激活。在 艾滋病患者中，弓形虫脑炎是局灶性脑损伤的最常见原因，可 即使经过适当的治疗也会导致长期的神经功能缺损。最近的研究还表明， 即使在接受有效抗逆转录病毒治疗的 HIV+ 患者中，持续的弓形虫感染也可能产生不利影响 影响认知和整体免疫反应。尽管它具有临床重要性，但我们缺乏机制 了解弓形虫在中枢神经系统中的发病机制的真正原因，包括什么 可实现长期潜伏感染。这种理解对于最终预防症状至关重要 HIV/艾滋病患者的疾病。在中枢神经系统内，囊肿主要存在于神经元中。基于有限 体外和体内研究，据推测，虽然受感染的星形胶质细胞清除了细胞内 寄生虫，神经元则不然，因此是持续感染的事实上的宿主细胞。在最后 十年来，我们的开创性工作对这一模型提出了质疑，包括表明 IFN-γ 刺激 神经元建立抗寄生虫防御。由于大部分工作都是在小鼠模型中进行的 神经元，它将错过人类神经元特异性通路（例如，人类缺乏末端 IFN-γ 鼠细胞用来杀死细胞内寄生虫的依赖蛋白）。这笔赠款的目标是 通过建立强大的干细胞衍生的人类神经元模型（hPSC 神经元）来解决这一差距 可用于机械地定义人类神经元-T。弓形虫相互作用可实现免疫逃避 和坚持。为了实现这一目标，我们将利用我们在 CNS 领域的协同专业知识 弓形体病 (Koshy 博士) 和干细胞生物学 (Churko 博士) 生成 Cre 报告 hPSC 神经元 和表达 CRISPRi 的 hPSC 神经元（目标 1），并开始定义其机制 细胞因子刺激的 hPSC 神经元控制弓形虫（目标 2）。完成这些目标后，我们将 已经建立并验证了工具，这些工具将构成长期计划的重要基础 从分子角度定义神经元-T。弓形虫相互作用，使弓形虫能够在体内得到控制和持久存在 人类神经元。这里提出的工作代表了人类发展的重要的第一步 针对急性和慢性弓形虫病的神经元特异性疗法。这样的疗法将会有很大的好处 针对有弓形虫脑炎风险的艾滋病毒/艾滋病人群。