Crosstalk between innate-immunity human microglia and adaptive-immunity Tregs in Alzheimer's disease

标题：先天免疫人类小胶质细胞和适应性免疫T细胞在阿尔茨海默氏症中的相互作用 疾病（RFA-AG-22-017） 项目摘要 本申请是对RFA-AG-22-017的回应，旨在研究先天性和后天性之间的串扰 阿尔茨海默病（AD）的免疫。AD影响约5%的65岁以上人群，其患病率为 增加。神经炎症已在神经退行性疾病中描述，特别是在AD中。 小胶质细胞是中枢神经系统（CNS）的常驻巨噬细胞，对不同的前体细胞有反应。 通过释放谷氨酸以及促炎细胞因子和趋化因子来抑制炎症刺激。谷氨酸 在暴露于Aβ和αSyn后，也观察到星形胶质细胞和小胶质细胞的释放， 在AD中被错误折叠。T淋巴细胞表达多种NMDA型谷氨酸受体（NMDAR），我们 还检测到它们在TdR中的表达，据报道，TdR的活性可以改善神经退行性变 紊乱使用膜片钳记录，我们的初步研究首次表明， 功能性NMDAR操作的离子通道。已知谷氨酸会影响T细胞迁移， 然而，谷氨酸对Treg迁移/活化的影响尚未报道，并且， 具体而言，尚不清楚这可能如何影响AD脑中的神经元。 我们假设，谷氨酸暴露于TdR会限制它们释放抗炎和抗氧化剂。 神经保护因子，从而导致神经元突触损伤和细胞损失。这段对话 先天性和获得性免疫系统可能是AD发病机制的重要因素。我们 最近开发了一种在卵黄囊后产生人iPSC衍生的小胶质细胞（hiMG）的方案， 分化方法（脑小胶质细胞来源于卵黄囊而不是骨髓）。我们将测试 我们的假设使用hiPSC衍生的小胶质细胞（hiMG）平台，人TCFs（从正常血液中分离 供体）和携带AD突变的hiPSC衍生的皮质神经元（hiN）（相对于它们的同基因/基因- 校正对照）。使用这个平台，我们在我们的初步研究中表明，hiMG释放谷氨酸 在用寡聚体Aβ和αSyn活化后。我们将系统地研究其机制， 通过hiMG释放的谷氨酸激活TcM，以及这种细胞串扰对神经元的影响 功能我们将评估神经元突触的完整性和功能以及神经元的存活。 从这项研究中获得的知识将揭示谷氨酸对神经炎症的影响， 人的背景下，并将提供深入了解人类小胶质细胞和Tclinin之间的串扰的影响 刺激Treg活化。因此，这项工作可能有助于未来新的治疗干预措施的发展 基于人类小胶质细胞和Treg的功能和相互作用。

Title: Crosstalk between innate-immunity human microglia and adaptive-immunity Tregs in Alzheimer’s disease (RFA-AG-22-017) Project Summary This application is in response to RFA-AG-22-017, looking at crosstalk between innate and acquired immunity in Alzheimer’s disease (AD). AD affects ~5% of people over age 65, and its prevalence is increasing. Neuroinflammation has been described in neurodegenerative disorders, and particularly in AD. Microglial cells, the resident macrophages of the central nervous system (CNS), respond to different pro- inflammatory stimuli by releasing glutamate, as well as pro-inflammatory cytokines and chemokines. Glutamate release from astrocytes and microglia has also been observed after exposure to Aβ and to αSyn, proteins that are misfolded in AD. T lymphocytes, express several NMDA-type glutamate receptors (NMDARs), and we have also detected their expression in Tregs, whose activity can reportedly ameliorate neurodegenerative disorders. Using patch-clamp recording, our Preliminary Studies show for the first time the presence of functional NMDAR-operated ion channels on human Tregs. Glutamate is known to affect T cell migration and activation; however, the effect of glutamate on Treg migration/activation has not been reported, and, specifically, it is not known how this might impact neurons in AD brain. We hypothesize that glutamate exposure of Tregs will limit their release of anti-inflammatory and neuroprotective factors, thus contributing to neuronal synaptic damage and cell loss. This crosstalk between the innate and acquired immune system may represent a significant contributor to the pathogenesis of AD. We have recently developed a protocol for generating human iPSC-derived microglia (hiMG) following a yolk sac differentiation method (brain microglia originate from the yolk sac and not from the bone marrow). We will test our hypothesis using a platform of hiPSC-derived microglia (hiMG), human Tregs (isolated from normal blood donors), and hiPSC-derived cerebrocortical neurons (hiN) bearing AD mutations (vs. their isogenic/gene- corrected controls). Using this platform, we show in our Preliminary Studies that hiMG release glutamate following activation with oligomeric Aβ and αSyn. We will systematically investigate the mechanism of the activation of Tregs by glutamate released by hiMG, and the effect of this cellular crosstalk on neuronal function. We will evaluate neuronal synaptic integrity and function as well as neuronal survival. The knowledge gained from this study will shed light on the effect of glutamate on neuroinflammation in a human context, and will provide insight into the effect of crosstalk between human microglial and Tregs in stimulating Treg activation. Thus, the work may aid in the development of future novel therapeutic interventions based on human microglial and Treg function and interaction.