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

标题：阿尔茨海默病患者先天免疫人类小胶质细胞与获得性免疫树突状细胞之间的串扰 疾病(RFA-AG-22-017) 项目摘要 此应用程序响应RFA-AG-22-017，查看先天和后天之间的串扰 阿尔茨海默病(AD)的免疫力。65岁以上的人中约有5%患有AD，其患病率为 越来越多。神经退行性疾病，尤其是阿尔茨海默病，已有神经炎症的描述。 小胶质细胞是中枢神经系统(CNS)的驻留巨噬细胞，对不同的前体细胞有不同的反应。 通过释放谷氨酸以及促炎细胞因子和趋化因子来刺激炎症。谷氨酸 星形胶质细胞和小胶质细胞在接触Aβ和αSyn后也观察到释放，这些蛋白质可以 都是在公元后错误折叠的。T淋巴细胞，表达几种NMDARs，我们 也检测到它们在Tregs中的表达，据报道，Tregs的活动可以改善神经退行性变 精神错乱。利用膜片钳记录，我们的初步研究首次显示出 人三叉神经节上NMDAR操作的功能性离子通道。已知谷氨酸影响T细胞迁移和 然而，谷氨酸对Treg迁移/激活的影响尚未报道，并且， 具体地说，目前还不知道这可能会如何影响AD大脑中的神经元。 我们假设谷氨酸暴露于Treg会限制其抗炎和 神经保护因素，从而导致神经元突触损伤和细胞丢失。这种串扰在 先天性和获得性免疫系统可能在AD的发病机制中起重要作用。我们 最近开发了一种在卵黄囊后产生人iPSC来源的小胶质细胞(HiMG)的方案 分化方法(脑小胶质细胞起源于卵黄囊而非骨髓)。我们将测试 我们的假设使用的是HiPSC来源的小胶质细胞(HiMG)平台，人的Tregs(从正常血液中分离出来 供体)，以及携带AD突变的HiPSC来源的大脑皮质神经元(Hin)(与其同基因/基因- 已更正控制)。利用这个平台，我们在我们的初步研究中表明，hiMG释放谷氨酸 用寡聚体Aβ和αSyn激活后。我们将系统地研究这一机制。 HiMG释放的谷氨酸激活Tregs及其对神经元的影响 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率。 从这项研究中获得的知识将有助于阐明谷氨酸对小鼠神经炎症的影响。 人类背景，并将深入了解人类小胶质细胞和树突之间的串扰在 刺激Treg的激活。因此，这项工作可能有助于未来新的治疗干预措施的开发 基于人类小胶质细胞和Treg的功能及相互作用。

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.