A novel blood-CSF adaptive immune response in Alzheimer's disease

阿尔茨海默病（AD）是一种无法治愈的神经退行性疾病，其中神经炎症越来越多地被认为起着关键作用。虽然先天性炎症与AD有关，但对适应性免疫反应的贡献知之甚少。本申请中的初步数据表明AD的外周免疫特征，其特征在于高度分化的CD 8 + T效应记忆CD 45 RA+（TEMRA）细胞数量增加。引人注目的是，CD 8 + TEMRA细胞也存在于患者脑脊液（CSF）中，并且T细胞受体（TCR）测序表明它们的克隆扩增，表明这些适应性免疫细胞的抗原特异性。TCR克隆和肽筛选证明了克隆扩增的AD CSF TCR亚组对EB病毒（EBV）BZLF 1抗原的特异性。这些结果提供了克隆的、抗原经历的T细胞在受年龄相关性神经变性影响的大脑鞘内空间巡逻的第一个证据。该K99/R 00应用将测试有助于AD病理学的有害适应性免疫反应的新理论。在特定目标1中，AD血液-CSF T细胞克隆型将与CSF生物标志物相关。这种方法将确定AD中的特定T细胞群以及这些细胞是否与疾病严重程度相关。在特定目标2中，抗原鉴定筛选将用于检测驱动AD中T细胞克隆扩增的自身/非自身抗原。这些测定可以发现AD的新的治疗靶点或生物标志物。具体目标3将使用与患者CSF CD 8 + T细胞共培养的诱导神经元（iN）细胞确定AD中T细胞介导的神经元死亡和弹性的机制。这些实验将评估AD CSF CD 8 + T细胞是否对感染EBV的iN细胞和/或BZLF 1的分子模拟物产生细胞毒性效应子应答。候选人大卫盖茨博士在T细胞生物学方面拥有丰富的经验，并花了十多年的时间研究AD。在该奖项的指导阶段，Gate博士的目标是提高他在下一代测序分析，复杂的统计方法，抗原筛选，iN培养方法和CRISPR基因编辑方面的知识。盖茨博士的导师和共同导师托尼·怀斯-科雷博士和马克·戴维斯博士分别在这些领域拥有全面的专业知识。他们将为Gate博士提供一个丰富的环境，使其成为神经免疫学研究领域的杰出独立研究者。作为一名独立的研究者，Gate博士将利用该奖学金下的培训，全面和定量地评估T细胞分子组分与神经退行性变之间的相互作用。

Alzheimer’s disease (AD) is an incurable neurodegenerative disorder in which neuroinflammation is increasingly recognized to play a critical function. While innate inflammation has been implicated in AD, little is known about the contribution of the adaptive immune response. Preliminary data featured in this application demonstrate a peripheral immune signature of AD characterized by increased numbers of highly differentiated CD8+ T effector memory CD45RA+ (TEMRA) cells. Strikingly, CD8+ TEMRA cells were also present in-patient cerebrospinal fluid (CSF) and T cell receptor (TCR) sequencing indicated their clonal expansion, suggesting antigen specificity of these adaptive immune cells. TCR cloning and peptide screens demonstrated specificity of a subset of clonally expanded AD CSF TCRs to the Epstein-Barr virus (EBV) BZLF1 antigen. These results provide the first evidence of clonal, antigen-experienced T cells patrolling the intrathecal space of brains affected by age-related neurodegeneration. This K99/R00 application will test the novel theory of a detrimental adaptive immune response contributing to AD pathobiology. In Specific Aim 1, AD blood-CSF T cell clonotypes will be related to CSF biomarkers. This approach will determine specific T cell populations in AD and whether these cells relate to disease severity. In Specific Aim 2, antigen identification screens will be used to detect the self/non-self-antigen(s) driving T cell clonal expansion in AD. These assays could uncover a novel therapeutic target or biomarker for AD. Specific Aim 3 will determine mechanisms of T cell-mediated neuronal death and resiliency in AD using induced neuronal (iN) cells co-cultured with patient CSF CD8+ T cells. These experiments will assess whether AD CSF CD8+ T cells mount cytotoxic effector responses to iN cells infected with EBV and/or to a molecular mimic of BZLF1. The candidate, Dr. David Gate, has extensive experience in T cell biology and has spent more than a decade studying AD. During the mentoring phase of this award, Dr. Gate aims to advance his knowledge in next-generation sequencing analysis, sophisticated statistical methods, antigen screening, iN culturing methods and CRISPR gene editing. Dr. Gate's mentor and co-mentor, Dr. Tony Wyss-Coray and Dr. Mark Davis, respectively, have comprehensive expertise in these areas. They will provide an enriching environment for Dr. Gate to develop as a prominent independent investigator in neuroimmunology research. As an independent investigator, Dr. Gate will leverage the training under this fellowship to comprehensively and quantitatively evaluate the interactions between T cell molecular components and neurodegeneration.