Analysis oftarget anfigens in oerebrospinal oligoclonal bands in multiple sclerosis patients

脑脊液（CSF）寡克隆IgG带（OS）是多发性硬化（MS）的重要实验室发现。由于其临床意义和靶抗原仍有待阐明，我们进行了以下分析。我们应用灵敏的等电聚焦（IEF）方法检测MS中的OB，发现常规MS（CMS）中OB的频率为67.9%，而光学脊髓MS（OSMS）中OB的频率为10%。有趣的是，OB阴性CMS患者的脑部MRI表现往往不典型。我们用噬菌体展示技术研究了脑脊液IgG抗原表位。在每种情况下，检测到共同的氨基酸序列，他们往往是同源的疱疹病毒蛋白。然而，每个患者的这些序列都是独特的。我们分析了一个OB阳性患者的3个CSF样本，并一致地检测到与EB病毒蛋白同源的相同序列。其中，与EB病毒ZEBRA蛋白同源的序列在VV-blot中与CSF的反应比与血清的反应强，提示与OB相关。合成GST融合蛋白，并在GST pull down试验中沉淀与融合蛋白反应的CSF IgG。CSF吸收后，进行IEF，但OB的带型不变。因此，OB的每条带可能由多种抗体组成。在复发期间获得的任何CSF样品中均未检测到病毒IL-10。有些患者有线性三叉神经根病变，这些独特的病变类似于动物单纯疱疹病毒感染引起的病变。1例OB阳性患者复发时脑脊液疱疹病毒抗体滴度升高。我们的研究证实了OB在MS中的发病意义。本研究中显示的与MS中CSF IgG反应的肽序列可能为进一步分析OB的靶抗原提供重要信息。

Cerebrospinal fluid (CSF) oligoclonal lgG band (OS) is an important laboratory finding in multiple sclerosis (MS). Since its clinical implication and target antigens remain to be elucidated, we conducted the following analyses. We applied the sensitive isoelectric focusing (IEF) method to detect OB in MS and found that the frequencies of OB were 67.9% in conventional MS (CMS) and 10% in optic-spinal MS (OSMS). Interestingly, the brain MRI findings in OB-negative CMS patients were often atypical. We studied the CSF lgG epitopes with the phage display method. Common aminoacid sequences were detected in each case, and they were frequently homogenous to herpes viral proteins. However, those sequences in each patient were unique. We analyzed the 3 CSF samples of an OB-positive patient and consistently detected the identical sequences homologous to EB viral proteins. Among them, the sequence homologous to EB viral ZEBRA protein reacted more to CSF than serum in VVestern blot, suggesting the relevance to OB. The GST fusion proteins were synthesized, and the CSF lgG reacted to the fusion protein were precipitated in the GST pull down assay. After the absorption, the CSF was subjected to IEF, but the banding pattern of OB was unchanged. Therefore, each band of OB probably consists of multiple antibodies. The viral IL-1O was not detected in any CSF sample obtained during relapse. Some patients have linear trigeminal root lesions, and these unique lesions are similar to those caused by herpes simplex viral infection in animals. The CSF antibody titers to herpes virus were elevated in one OB-positive patient with such lesion during relapse. Our study demonstrated the pathogenetic significance of OB in MS. The peptide sequences shown to react to CSF lgG in MS in the present study may be an important information to further analyze the target antigens of OB.