Pathogenic mechanism of intrathecally synthesized immunoglobulins in a mouse model of progressive multiple sclerosis

项目总结/摘要 复发性和进行性多发性硬化（MS）的特征是鞘内合成 免疫球蛋白（IIgS）。这发生在整个疾病，是唯一广泛同意的分子 越来越多的证据也表明IIgS与MS疾病相关， 进展，虽然这些抗体的病理作用仍有待确定。 中枢神经系统（CNS）中的细胞毒性活动是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性机制： 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触发CNS内的ADCC和CDC，从而累积CNS损伤并使疾病恶化 进展因此，在过去的几年里，我工作的主要目标是确定细胞毒活性 这些免疫球蛋白通过使用Theiler的小鼠脑脊髓炎病毒诱导的脱髓鞘疾病（TMEV-IDD）作为一种免疫抑制剂， 特别是，我一直专注于CDC和经典补体途径。 经典补体途径的第一组分（C1 q）识别并结合与补体复合的Ig。 抗原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C1 q水平越高，表明临床和病理疾病越严重，我开发了一种改进的 工作假设因此，我现在假设TMEV-IDD小鼠CNS中C1 q的治疗性抑制 将通过减少神经轴突损伤和神经炎症来预防疾病进展。我来测试一下 假设通过实现以下三个目标： 目的1将证明抗C1 q治疗可改善临床结局。为了实现这一目标，TMEV- IDD小鼠将用心室内注射的鼠抗C1 q抗体（M1）或全身注射的抗C1 q抗体（M2）治疗。 施用抗C1 q骆驼VHH抗体（aka纳米抗体）。将评价运动和认知结局。 目的2将证明抗C1 q治疗可减少神经轴突损伤。为了实现这一目标， 在整个疾病过程中，通过以下方式评估治疗小鼠与未治疗小鼠的神经轴突损伤：1）测量 神经轴突损伤的脑脊液（CSF）生物标志物，2）组织学，和3）定量磁共振成像 共振成像（MRI）技术。 目标3将证明抗C1 q治疗可减少神经炎症。为了实现这一目标， 通过1）流式细胞术，2）免疫荧光， 和3）测量鞘内产生的炎性生物标志物。 总的来说，这项工作将为IIGS在PMS中发挥的重要作用提供令人信服的证据， 为它的治疗定义了一个新的范例。

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.