Seronegative Autoimmune Encephalopathies: Biomarker Discovery, Validation & Deep Phenotyping

项目摘要 自身免疫性脑炎的发病率超过感染性病因，但50%（约为 4000/年（美国）为IgG生物标志物阴性。血清阴性妨碍诊断和病理生理学 了解自身免疫性脑病（脑炎、小脑共济失调和其他运动 疾病）。试图解决这一差距的新型IgG表征是线性的，并且在一定的时间内缓慢发生。 1-2年的发病率（使用标准的基于组织的免疫荧光测定[IFA]，然后进行蛋白质印迹， 免疫沉淀和质谱法）。长期目标是从分子水平、临床水平和 机械地表征自身免疫性脑病，并开发靶向自身免疫性疗法。的 本申请的总体目的是：1）鉴定血清阴性的疾病特异性生物标志物， 自身免疫性脑病; 2）分子验证新的生物标志物，和3）临床、放射学和 免疫学深层表型自身免疫性脑病。中心假设是血清阴性 自身免疫性脑病可通过生物标志物发现来表征。该项目的基本原理是 生物标志物的发现和翻译可以迅速发生，通过利用互补技术， 与此同时，新的生物标志物可以在分子上得到验证，与新的生物标志物相关的疾病也可以在分子上得到验证。 生物标志物可以是神经学和免疫学深度表型的。为了检验中心假设， 将追求以下三个具体目标：1）鉴定新的生物标志物，最初在3个部分表征的 血清阴性自身免疫性脑病; 2）确定新生物标志物的有效性;和3）评估 分化的临床表型和细胞因子谱测定。在第一个目标下，血清和CSF 来自血清阴性自身免疫性脑病患者的神经抗体将使用天然的 全长蛋白质微阵列，作为主要技术，辅以组织和细胞为基础的IFA， IgG筛选，以及根据需要，噬菌体免疫沉淀测序和质谱技术 以供核实。对于第二个目标，将在自身免疫性脑病中验证新表征的IgG 通过多种抗原特异性方法（共聚焦间接免疫荧光，和 重组蛋白测定[蛋白质印迹，基于cDNA转染的细胞]）。对于第三个目标， 具有特征化和验证的神经IgG的自身免疫性脑病将在临床上进行深度表型分型， 放射学和免疫学上，通过在活神经元测定中评价IgG效应，以及 数据区.剩余血清阴性队列将通过精氨酸-趋化因子测定进行免疫学分析。的 在申请人看来，所提出的研究是创新性的，因为它集中于多重生物标志物鉴定， 验证和深度表型分析。这项拟议中的研究意义重大，因为疾病特异性生物标志物， 通过深入的表征，允许早期诊断和治疗，并支持疾病机制研究。

PROJECT SUMMARY Incidence of autoimmune encephalitis exceeds that of infectious cause, but 50% percent (half of approximate 4000/year in the US) are IgG biomarker negative. Seronegativity hinders diagnosis and pathophysiologic understanding in autoimmune encephalopathies (encephalitis, cerebellar ataxias and other movement disorders). Novel IgG characterization, which attempts to address this gap, is linear and slow occurring at a rate of 1-2 year (using standard tissue-based immunofluorescence assay [IFA] followed by western blots, immunoprecipitation, and mass spectrometry). The long-term goal is to molecularly, clinically and mechanistically characterize autoimmune encephalopathies, and develop targeted autoimmune therapies. The overall objectives in this application, are to: 1) identify disease-specific biomarkers for seronegative autoimmune encephalopathies; 2) molecularly validate novel biomarkers, and 3) clinically, radiologically and immunologically deep-phenotype autoimmune encephalopathies. The central hypothesis is that seronegative autoimmune encephalopathies are characterizable though biomarker discovery. The rationale for this project is that biomarker discovery and translation could occur expeditiously, by leveraging complementary techniques in parallel, that novel biomarkers could be molecularly validated, and that disorders associated with new biomarkers could be neurologically and immunologically deep-phenotyped. To test the central hypothesis the following three specific aims will be pursued: 1) Identify novel biomarkers, initially in 3 partly characterized seronegative autoimmune encephalopathies; 2) determine validity of novel biomarkers; and 3) assess for differentiated clinical phenotypes, and cytokine profile accompaniments. Under the first aim, serum and CSF from seronegative autoimmune encephalopathy patients will be interrogated for neural antibodies using native full-length protein microarrays, as principle technique, complemented by tissue and cell-based IFA for initial IgG screening, and, as needed, phage immunoprecipitation sequencing, and mass spectrometry techniques for verification. For the second aim, newly characterized IgGs will be validated in autoimmune encephalopathy patients and controls by multiple antigen-specific methods (confocal indirect immunofluorescence, and recombinant protein assays [western blot, cDNA-transfected cell-based]). For the third aim, patients with autoimmune encephalopathies with characterized and validated neural IgGs will be deep-phenotyped clinically, radiologically and immunologically, by evaluating for IgG effects in live neuron assays, and cytokine-chemokine profiles. Remaining seronegative cohorts will be immunologically profiled by cytokine-chemokine assays. The research proposed is innovative in the applicant’s opinion, as it focuses on multiplexed biomarker identification, validation, and deep phenotyping. The proposed research is significant because disease-specific biomarkers, with in-depth characterization, allow earlier diagnosis and treatment, and support disease mechanism studies.