Oligoclonal bands and increased IgG antibody levels can be detected in the cerebrospinal fluid in vast majority of patients with Multiple Sclerosis (MS). However, the antigenic specificity of oligoclonal IgG has yet to be determined. Using laser capture microdissection, we isolated single CD38+ plasma cells from lesion areas in two autopsy MS brains, and generated three recombinant antibodies (rAbs) from clonally expanded plasma cells. Panning phage-displayed random peptide libraries was carried out to determine peptide antigen specificities of these MS brain rAbs. We identified 25 high affinity phage peptides from which 5 peptides are unique. Database searches revealed that they shared sequence homologies with Epstein-Barr nuclear antigens 4 and 6, as well as with other viral proteins. Significantly, these peptides were recognized by intrathecal IgG and oligoclonal IgG bands in other MS patients. Our results demonstrate that functional recombinant antibodies can be generated from clonally expanded plasma cells in MS brain lesions by laser capture microdissection, and that these MS brain rAbs have the potential for determining the targets of intrathecal IgG and oligoclonal bands.

中文翻译：

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来自激光捕获的多发性硬化脑单个浆细胞的重组抗体鉴定了噬菌体肽，可用作表征鞘内 IgG 反应的工具

在绝大多数多发性硬化症 (MS) 患者的脑脊液中可以检测到寡克隆带和 IgG 抗体水平升高。然而，寡克隆 IgG 的抗原特异性尚未确定。使用激光捕获显微切割，我们从两个尸检 MS 大脑的病变区域中分离出单个 CD38+ 浆细胞，并从克隆扩增的浆细胞中生成三种重组抗体 (rAb)。进行了淘选噬菌体展示的随机肽文库以确定这些 MS 脑 rAb 的肽抗原特异性。我们鉴定了 25 种高亲和力噬菌体肽，其中 5 种肽是独一无二的。数据库搜索显示它们与 Epstein-Barr 核抗原 4 和 6 以及其他病毒蛋白具有序列同源性。显着地，这些肽被其他 MS 患者的鞘内 IgG 和寡克隆 IgG 条带识别。我们的结果表明，可以通过激光捕获显微切割从 MS 脑病变中克隆扩增的浆细胞中产生功能性重组抗体，并且这些 MS 脑 rAb 具有确定鞘内 IgG 和寡克隆带靶标的潜力。