The role of apolipoprotein E in Alzheimer's adaptive immunity

项目摘要 载脂蛋白E（Apolipoprotein E，APOE）基因多态性是AD发病的主要遗传因素。一个未开发 ApoE在AD病理生物学中的功能是其在免疫调节和对病毒感染的易感性中的作用。 最初在外周遇到抗原的T细胞可以通过全身免疫系统进入脑脊液（CSF）。 流通然而，这一过程背后的抗原尚不清楚。这里显示的初步数据 表明AD的外周适应性免疫特征，其特征在于CD8+细胞数量增加， 效应T细胞我们的数据进一步表明，APOE等位基因依赖的CD8 T效应细胞数量的差异， AD的血引人注目的是，CD8效应T细胞也存在于患者CSF和T细胞受体（TCR）测序中。 表明它们针对EB病毒（EBV）BZLF1抗原的克隆扩增。此外，CSF分析 TCR序列表明APOE4携带者中针对EBV的CD8 T效应细胞克隆扩增增加。这些 结果表明，抗原感受性T细胞在APOE中受AD影响的脑的鞘内空间巡逻， 等位基因特异性方式。我们假设CD8 T细胞在APOE 4 AD患者的血液和CSF中巡逻， 通过异常的抗病毒抗原控制导致神经炎症。特异性目标1将利用单细胞RNA 测序（scRNAseq）和免疫组织化学来确定APOE等位基因对适应性 AD大脑中的免疫力Specific Aim 2将使用高通量scRNAseq评估B和T细胞克隆 各种APOE携带者外周血中的扩增结合复杂的生物信息学方法 以APOE等位基因依赖性方式比较抗病毒适应性免疫细胞的转录组。 Specific Aim 3将采用ApoE结构校正剂和CRISPR基因编辑来确定其机制。 ApoE对抗病毒免疫应答和T细胞杀伤神经元的影响。这些研究将在 在大卫盖茨博士的实验室里，他是一位早期研究者，在研究T细胞、抗病毒药物和免疫系统方面有着丰富的经验。 免疫和神经变性。合作者包括罗伯特·马利博士（格莱斯顿研究所），他 具有ApoE生物学专业知识的Robert Vassar博士（西北大学），具有AD病理生物学专业知识， 和马塞尔梅苏拉姆博士，谁将提供通过西北梅苏拉姆访问患者标本 认知神经学和阿尔茨海默病中心。

Project Summary Apolipoprotein E (APOE) polymorphic alleles are the main genetic determinants of AD risk. An unexplored function of ApoE in AD pathobiology is that of its role in immune modulation and susceptibility to viral infection. T cells that initially encounter antigen in the periphery can enter the cerebrospinal fluid (CSF) via the systemic circulation. However, the antigens underlying this process are not clear. Preliminary data shown here demonstrates a peripheral adaptive immune signature of AD characterized by an increased number of CD8 effector T cells. Our data further indicates APOE allele-dependent differences in CD8 T effector cell numbers in AD blood. Strikingly, CD8 effector T cells were also present in patient CSF and T cell receptor (TCR) sequencing indicates their clonal expansion against the Epstein-Barr virus (EBV) BZLF1 antigen. Further, analysis of CSF TCR sequences indicates increased CD8 T effector cell clonal expansion against EBV in APOE4 carriers. These results indicate that antigen-experienced T cells patrol the intrathecal space of brains affected by AD in an APOE allele-specific manner. We hypothesize that CD8 T cells patrol the blood and CSF of APOE4 AD patients and contribute to neuroinflammation via aberrant anti-viral antigen control. Specific Aim 1 will utilize single cell RNA sequencing (scRNAseq) and immunohistochemistry to determine the influence of APOE alleles on adaptive immunity in the AD brain. Specific Aim 2 will use high throughput scRNAseq to assess B and T cell clonal expansion in peripheral blood of various APOE carriers combined with sophisticated bioinformatic approaches to compare the transcriptomes of anti-viral adaptive immune cells in an APOE allele-dependent manner. Specific Aim 3 will employ ApoE structure correctors and CRISPR gene editing to determine the mechanistic impact of ApoE on the anti-viral immune response and T cell killing of neurons. These studies will be conducted in the lab of Dr. David Gate, an early-stage investigator who has extensive experience studying T cells, anti-viral immunity and neurodegeneration. Collaborators include Dr. Robert Mahley (Gladstone Institute), who has expertise in ApoE biology, Dr. Robert Vassar (Northwestern University), who has expertise in AD pathobiology, and Dr. Marsel Mesulam, who will provide access to patient specimens through the Northwestern Mesulam Center for Cognitive Neurology and Alzheimer's Disease.