Defining the autoimmune mechanisms driving human MOG antibody disease pathology

项目摘要。髓鞘少突胶质细胞糖蛋白抗体病(MOGAD)是一种炎症性疾病 脱髓鞘的中枢神经系统疾病。MOGAD是一种新定义的自身免疫性疾病，具有 多发性硬化(MS)和水通道蛋白4(AQP4)自身抗体阳性的临床表型重叠 视神经脊髓炎谱系障碍(NMOSD)，但这三种情况现在都被认为是不同的。 MOGAD以IgG1亚类MOG特异性自身抗体为特征。患者可以用视觉， 运动、活动、膀胱、肠道和/或认知功能障碍。MOG自身抗体的作用机制 介导性病理学还没有被很好地理解。考虑到现有的治疗方法，理解这一点很重要 可以针对这些自身抗体效应器功能的药物。此外，表达MOG的特定B细胞亚型 自身抗体还没有被确认。我们知识中的这种额外差距也带来了以下后果 MOGAD患者的治疗，考虑到不同的治疗性B细胞去除方法对 不同的B细胞亚群。 为了解决我们对这种疾病理解上的这些差距，我们将：(I)产生人类单克隆性 来自患者的MOG自身抗体；(Ii)使用新的方法来定义和测量不同的机制 MOG自身抗体的致病性。特别关注补体依赖性细胞毒性(CDC)和 抗体依赖的细胞毒性(ADCC)，因为人类IgG1抗体包括这些致病因子 机制，以及(Iii)对表达人MOG的特定B细胞进行深层单细胞表型鉴定 自身抗体。 为了实现这些目标，我们开发了一种无偏见的高通量方法来生产MOG- 通过克隆单个B细胞获得特异性人源单抗。这种方法将能够生产出多样化的特定于MOG的产品 MAB库。研究MOG自身抗体致病不同效应机制的新途径 也被开发出来了。具体地说，我们开发了高通量的流式细胞仪分析来测量 表达人MOG的活细胞的补体活性、CDC和ADCC。这些实验将定义 MOG自身抗体的特异性和分子特性与致病效应的关系 功能。最后，我们将使用高维数据定义产生自身抗体的B细胞亚群的表型 流式细胞术和单细胞RNA测序方法。 总体而言，这项调查将：(I)提供一套特征良好的人类单抗，作为工具 更准确地模拟MOGAD病理；(Ii)确定自身抗体产生的细胞贡献者 (Iii)以及重要的翻译价值，确定治疗MOGAD的潜在新治疗途径 通过特定靶向MOG自身抗体效应器功能(使用补体抑制剂)和/或 自身反应性B细胞通过CD19或CD20介导的B细胞耗竭治疗而产生。

Project Summary. Myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOGAD) is an inflammatory demyelinating central nervous system condition. MOGAD is a newly defined autoimmune disease that has clinical phenotypic overlap with multiple sclerosis (MS) and aquaporin 4 (AQP4) autoantibody positive neuromyelitis optica spectrum disorder (NMOSD), but all three conditions are now recognized as being distinct. MOGAD is characterized by IgG1 subclass MOG-specific autoantibodies. Patients can present with visual, motor, ambulatory, bladder, bowel and/or cognitive dysfunction. The mechanisms by which MOG autoantibodies mediated pathology is not well understood. This is important to understand given the availability of therapeutics that can target these autoantibody effector functions. In addition, the specific B cell subtypes that express MOG autoantibodies have not been identified. This additional gap in our knowledge also presents consequences for MOGAD patient treatment, given that different therapeutic B cell depletion approaches are effective against distinct B cell subsets. To address these gaps in our understanding of this disease we will: (i) Generate human monoclonal MOG autoantibodies from patients; (ii) Use novel approaches to define and measure the different mechanisms of MOG autoantibody pathogenicity. Specifically focusing on complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC), given that human IgG1 antibodies include these pathogenic mechanisms, and (iii) Perform deep single cell phenotyping on the specific B cells that express human MOG autoantibodies. To accomplish these aims, we have developed a unbiased high-throughput approach for producing MOG- specific human mAbs by cloning single B cells. This approach will afford production of a diverse MOG-specific mAb library. New approaches to study the different effector mechanisms of MOG autoantibody pathogenicity have also been developed. Specifically, we developed high-throughput flow cytometry assays to measure complement activity (CA), CDC, and ADCC of live cells expressing human MOG. These experiments will define how the specificity and molecular properties of MOG autoantibodies are associated with pathogenic effector function. Finally, we will define the phenotypes of autoantibody-producing B cell subsets using high dimensional flow cytometry and single cell RNA sequencing approaches. Overall, this investigation will: (i) provide a set of well-characterized human mAbs which will serve as tools for more accurate modeling of MOGAD pathology; (ii) identify the cellular contributors to autoantibody production (iii) and importantly for translational value, identify potential new therapeutic avenues for treating MOGAD through specifically targeting MOG autoantibody effector functions (with complement inhibitors) and/or production by autoreactive B cells through CD19 or CD20-mediated B cell depletion therapy.