B CELL RESPONSES IN MULTIPLE SCLEROSIS

增加的免疫球蛋白和寡克隆条带(OGB)仅在 中枢神经系统感染性和炎症性疾病患者的脑脊液， 尤其是多发性硬化症。尽管他们对多发性硬化症的特异性是 未知，在中枢神经系统的传染病中，OGB是针对 致病因子，从而为我们的假设提供了理论基础 多发性硬化症脑和脑脊液中的OGB针对引起 疾病。区分特定的和随机的幽默 作为回应，我们对重链(V/H)和轻链(V/L)进行了序列测定 区域在多个急性MS斑块中表达，并发现受限的 反应主要由V/H4生殖系基因组成。几个V/H序列 被过度表示、克隆扩展并显示为非随机 体细胞突变的积累，这是一种抗原的特征 驱动B细胞反应。亚急性硬化症的平行分析 全脑炎(SSPE)的大脑也显示出过度代表和 体细胞突变的V/H和V/L序列。我们共同表达了这些序列 在哺乳动物表达载体中的表达结果表明，重组的免疫球蛋白是 受感染组织培养中麻疹病毒(引起SSPE的原因)的特异性 细胞。我们将利用我们在重组麻疹病毒特异性方面的成功 检测SSPE脑内麻疹抗原的抗体。信息 从SSPE中积累的将用于合成重组抗体 从候选的MS序列中证明其免疫学特异性， 无论是蛋白质还是碳水化合物抗原。一旦专一性是 建立后，我们将筛选从MS Brain到 鉴定和鉴定其蛋白产物与MS反应的cDNA 重组抗体或从急性MS斑块中提纯的免疫球蛋白。我们会 还继续对急性MS斑块的V/H区域进行测序以确定 如果限制使用特定的V/H4或其他家庭生殖系 我们为进行这些研究做好了充分的准备 因为我们有：(A)经病理证实的急性多发性硬化症大脑和非多发性硬化症 神经系统疾病大脑；(B)已证明的识别疾病的能力- 从人脑中提取相关的免疫球蛋白序列，并利用这些序列 产生针对致病病原体的重组免疫球蛋白； 构建和筛选复合体基因的分子生物学专业知识 文库；和(D)含有MS和其他中枢神经系统患者OGB的脑脊液 炎症性疾病。对多发性硬化症特异性抗原的鉴定将具有 广泛应用，不仅是为了早期确诊，也是为了 制定调控(如果不是预防)疾病的战略。

Increased IgG and oligoclonal bands (OGBs) are found exclusively in the CSF of patients with infectious and inflammatory diseases of the CNS, particularly multiple sclerosis (MS). Although their specificity in MS is unknown, in infectious diseases of the CNS, OGBs are specific for the agent that causes disease, thus providing a rationale for our hypothesis that OGBs in MS brain and CSF are directed against the antigen that causes disease. To distinguish between a specific versus a random humoral response, we sequenced IgG heavy (V/H) and light (V/L) chain variable regions expressed in multiple acute MS plaques and found a restricted response consisting primarily of V/H4 germline genes. Some V/H sequences were over-represented, clonally expanded, and displayed a non-random accumulation of somatic mutations, features indicative of an antigen driven B cell response. A parallel analysis of subacute sclerosing panencephalitis (SSPE) brain also revealed over-represented and somatically mutated V/H and V/L sequences. We co-expressed these sequences in mammalian expression vectors and showed that the recombinant IgG was specific for measles virus (the cause of SSPE) in infected tissue culture cells. We will exploit our success with recombinant measles virus specific antibody to identify measles antigen in SSPE brain. Information accumulated from SSPE will be used to synthesize recombinant antibodies from candidate MS sequences to demonstrate their immunologic specificity, for either protein or carbohydrate antigens. Once specificity is established, we will screen phage display cDNA libraries from MS brain to identify and characterize cDNAs whose protein products react with MS recombinant antibodies or with IgG purified from acute MS plaques. We will also continue to sequence V/H regions from acute MS plaques to determine if restricted use of specific V/H4 or other family germlines is characteristic of MS. We are well-prepared to conduct these studies because we have: (a) pathologically verified acute MS brains and non-MS neurologic disease brains; (b) a demonstrated ability to identify disease- relevant IgG sequences from human brain, and to use these sequences to generate recombinant IgG specific for the agent that causes disease; (c) the expertise in molecular biology to construct and screen complex cDNA libraries; and (d) CSF containing OGBs from patients with MS and other CNS inflammatory diseases. Identification of an MS-specific antigen will have wide application, not only for early definitive diagnosis, but also for developing strategies for modulation, if not prevention, of disease.