Quantitative Analysis of Serum Autoantibody Repertories in Systemic Lupus Erythematosus

摘要 系统性红斑狼疮(SLE)是一种多器官、全身性自身免疫性疾病，估计影响 至少有150万美国人。系统性红斑狼疮的特征是产生血清自身抗体，这是一个统一的特征 出现在99%以上的未经治疗的患者中。这种自身抗体是直接致病的，最终导致 系统性红斑狼疮的症状包括虚弱的关节疼痛和皮疹，随后是器官损害和早期死亡。 先前的研究表明，自身抗体在系统性红斑狼疮症状出现前几个月到几年内就开始积累。 这可能允许一个窗口，用于检测它们并开始药物治疗，以防止或至少延迟 系统性红斑狼疮发病。然而，这些血清自身抗体由血液中的一种复杂混合物组成，包括 致病、非致病和有益的抗体，数量可能数以百万计。当当前 诊断平台可以在自身免疫性疾病期间筛查总自身抗体，找到特定的 与系统性红斑狼疮的发展有关的单抗目前是不可能的。因此，缺乏 直接检测单克隆性、致病性、自身抗体的能力是 了解自身抗体是如何产生的，迫切需要开发先进的分析工具来 描述这些抗体的特征。我们的长期目标是了解SLE自身抗体的发展 并开发具有高诊断价值的自身抗体生物标志物。这样做的总体目标是 建议建立一个新的综合蛋白质组学平台，利用两个互补的科学 方法，用于发现自身抗体生物标记物的定量自上而下MS方法，以及自上而下 用于自身抗体生物标志物验证和功能鉴定的蛋白质组学测序方法。 我们提出的自上而下的自身抗体蛋白质组学平台将用于鉴定完整的自身抗体Fab 纵向SLE血清样本中的信号。因此，我们将提供第一个自上而下的蛋白质组学平台 用于在克隆水平上表征SLE自身抗体。在系统性红斑狼疮分析中的应用 自身抗体将为SLE的预后、干预和预防提供新的策略基础，并 可能导致新的高诊断价值的生物标志物。经过开发，我们自上而下的自身抗体 表征平台可以很容易地适应其他自身免疫性疾病，如干燥综合征。

SUMMARY Systemic Lupus Erythematosus (SLE) is a multi-organ, systemic autoimmune disorder, estimated to affect at least 1.5 million Americans. The hallmark of SLE is the production of serum autoantibodies, a unifying feature present in over 99% of untreated patients. Such autoantibodies are directly pathogenic, eventually causing the symptoms of SLE including debilitating joint pain and rashes, followed by organ damage and early mortality. Previous work has shown that autoantibodies begin to accrue months to years before the symptoms of SLE appear which may allow a window for detecting them and starting medications to prevent or at least delay the onset of SLE. These serum autoantibodies, however, consist of a complex mixture in the blood including pathogenic, non-pathogenic, and beneficial antibodies which may number in the millions. While current diagnostic platforms can screen for total autoantibodies during autoimmune disease, finding specific monoclonal autoantibodies linked to the development of SLE is currently impossible. Thus, the lack of capability to directly detect monoclonal, pathogenic, autoantibodies presents a significant barrier in understanding how autoantibodies arise, and there is a critical need to develop advanced analytical tools to characterize these antibodies. Our long-term goal is to understand SLE autoantibody development at the monoclonal level and to develop high diagnostic value autoantibody biomarkers. The overall objective of this proposal to establish a novel integrated proteomics platform that employs two complementary scientific approaches, a quantitative top-down MS approach for autoantibody biomarker discovery, and a top-down proteogenomics sequencing approach for autoantibody biomarker validation and functional characterization. Our proposed top-down autoantibody proteomics platform will be applied to identify intact autoantibody Fab signatures in longitudinal SLE serum samples. As a result, we will provide a first top-down proteomics platform for characterizing SLE autoantibodies at the monoclonal level. Applying it to the analysis of SLE autoantibodies will provide foundations for new strategies in SLE prognosis, intervention, and prevention, and may lead to novel high diagnostic value biomarkers. After development, our top-down autoantibody characterization platform can be easily adapted to other autoimmune diseases such as Sjogren’s Syndrome.