Pathogenic Mechanism of Intrathecally Synthesized Immunoglobulins in a Mouse Model of Progressive Multiple Sclerosis

项目摘要/摘要 复发和进行性多发性硬化症(MS)的特点是鞘内合成 免疫球蛋白(IIGS)。这在整个疾病中都会发生，也是唯一被广泛认同的分子 MS的诊断标准越来越多的证据也表明IIGS与MS疾病相关 进展，尽管这些抗体的病理作用仍有待确定。 中枢神经系统(CNS)中的细胞毒活动是MS疾病进展的关键决定因素。 有趣的是，抗体可以激活两种不同的细胞毒机制：抗体依赖细胞介导 细胞毒性(ADCC)和补体依赖性细胞毒性(CDC)。因此，我最初假设，在 MS、IIGS在中枢神经系统内触发ADCC和CDC，从而导致中枢神经系统损伤和疾病恶化 进步。因此，在过去的几年里，我工作的主要目标一直是定义细胞毒活性 通过使用泰勒氏小鼠脑脊髓炎病毒诱导的脱髓鞘疾病(TMEV-IDD)作为 进展性多发性硬化症的模型特别是CDC和经典补体途径。 经典补体途径的第一组分(C1q)识别并结合到复杂到 并启动补体级联反应，最终触发CDC。因为我的研究结果表明 中枢神经系统中C1q水平的升高预示着临床和病理疾病的加重，我养成了精炼的 工作假说。因此，我现在假设C1q在TMEV-IDD小鼠的中枢神经系统中的治疗性抑制 将通过减少神经轴突损伤和神经炎症来防止疾病进展。我要测试一下这个 通过实现以下三个目标来实现假设： 目的1将证明抗C1q治疗可改善临床结果。为了实现这一目标，TMEV- IDD小鼠将接受脑室注射小鼠抗C1q抗体(M1)或全身注射 注射抗C1q骆驼VHH抗体(又名纳米体)。将对运动和认知结果进行评估。 目的2将证明抗C1q治疗可减少神经轴突损伤。为了实现这一目标， 经过治疗的小鼠和未接受治疗的小鼠的神经轴突损伤将通过测量在整个疾病过程中进行评估 神经轴突损伤的脑脊液生物标志物，2)组织学，3)定量磁学 磁共振成像(MRI)技术。 目标3将证明抗C1q治疗可减少神经炎症。为了实现这一目标， 将通过1)流式细胞术，2)免疫荧光， 3)鞘内产生的炎症生物标志物的测定。 总体而言，这项工作将提供令人信服的证据，证明IIGs在经前综合征中发挥的重要作用，从而 为其治疗定义了一种新的范例。

Project Summary/Abstract Relapsing and progressive multiple sclerosis (MS) are characterized by an intrathecal synthesis of immunoglobulins (IIgS). This occurs throughout the disease and is the only widely agreed upon molecular diagnostic criteria for MS. A growing body of evidence also suggests that IIgS correlates with MS disease progression, although the pathological role of these antibodies remains to be determined. Cytotoxic activities in the central nervous system (CNS) are critical determinants of MS disease progression. Interestingly, antibodies can activate two distinct cytotoxic mechanisms: antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Therefore, I initially hypothesized that, in MS, IIgS triggers ADCC and CDC within the CNS, thereby accruing CNS damage and worsening disease progression. Thus, over the past few years, the primary goal of my work has been to define the cytotoxic activity of these Igs by using Theiler’s murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD) as a model of progressive MS. Particularly, I have been focusing on CDC and the classical complement pathway. The first component of the classical complement pathway (C1q) recognizes and binds to Igs complexed to antigen and initiates the complement cascade, ultimately triggering CDC. Since the results of my studies suggest higher levels of C1q in the CNS indicate more severe clinical and pathological disease, I developed a refined working hypothesis. Thus, I now hypothesize that therapeutic inhibition of C1q in the CNS of TMEV-IDD mice will prevent disease progression by reducing neuroaxonal damage and neuroinflammation. I will test this hypothesis by accomplishing the following three aims: Aim 1 will demonstrate that anti-C1q treatment improves clinical outcomes. To accomplish this aim, TMEV- IDD mice will be treated with either an intraventricularly injected murine anti-C1q antibody (M1) or a systemically administered anti-C1q camelid VHH antibody (aka nanobody). Motor and cognitive outcomes will be evaluated. Aim 2 will demonstrate that anti-C1q treatment reduces neuroaxonal damage. To accomplish this aim, neuroaxonal damage in treated vs. untreated mice will be assessed throughout the disease by 1) measurement of cerebrospinal fluid (CSF) biomarkers of neuroaxonal damage, 2) histology, and 3) quantitative magnetic resonance imaging (MRI) techniques. Aim 3 will demonstrate that anti-C1q treatment reduces neuroinflammation. To accomplish this aim, neuroinflammation will be assessed in treated and untreated mice by 1) flow cytometry, 2) immunofluorescence, and 3) measurement of intrathecally produced inflammatory biomarkers. Overall, this work will provide compelling evidence for the significant role played by IIgs in PMS, thereby defining a new paradigm for its treatment.