The role of apolipoprotein E in Alzheimer's adaptive immunity

项目摘要 载脂蛋白E(ApoE)等位基因是AD风险的主要遗传决定因素。一位未经探索的人 载脂蛋白E在AD病理生物学中的作用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细胞可以通过全身性的 发行量。然而，这一过程背后的抗原尚不清楚。此处显示的初步数据 显示AD的外周适应性免疫特征，其特征是CD8数量增加 效应器T细胞。我们的数据进一步表明，载脂蛋白E等位基因在CD8T效应细胞数量上的差异 公元后的鲜血。值得注意的是，CD8效应T细胞也出现在患者的脑脊液和T细胞受体(TCR)序列中 表明它们针对EB病毒(EBV)BZLF1抗原的克隆性扩增。此外，对脑脊液的分析 TCR序列显示APOE4携带者抗EBV的CD8T效应细胞克隆性增殖增加。这些 结果表明，在APOE中，经历抗原的T细胞在受AD影响的脑鞘内巡逻 等位基因特有的方式。我们假设CD8 T细胞在APOE4 AD患者的血液和脑脊液中巡逻，并 通过异常的抗病毒抗原控制导致神经炎症。特定目标1将利用单细胞RNA 用单链RNA序列分析和免疫组织化学方法确定载脂蛋白E等位基因对适应性的影响 阿尔茨海默病大脑中的免疫力。特殊目标2将使用高通量scRNAseq来评估B和T细胞克隆 各种载脂蛋白E携带者外周血扩增结合复杂的生物信息学方法 以载脂蛋白E等位基因依赖的方式比较抗病毒获得性免疫细胞的转录。 特殊目标3将使用载脂蛋白E结构校正器和CRISPR基因编辑来确定机制 载脂蛋白E对神经元抗病毒免疫反应和T细胞杀伤的影响这些研究将进行 在David Gate博士的实验室里，David Gate博士是一名早期研究员，他对T细胞、抗病毒药物有丰富的研究经验 免疫和神经退行性变。合作者包括格雷斯顿研究所的罗伯特·马利博士，他已经 在载脂蛋白E生物学方面的专业知识，罗伯特·瓦萨尔博士(西北大学)，他在AD病理生物学方面有专业知识， 和Marsel Mesulam博士，他将通过西北Mesulam提供对患者标本的访问 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.