Gause A, Gundlach K, Zdichavsky M, Jacobs G, Koch B, Hopf T, Pfreundschuh M
Universitätskliniken des Saarlandes, Homburg/Saar, Germany.
Eur J Immunol. 1995 Oct;25(10):2775-82. doi: 10.1002/eji.1830251010.
The participation of the humoral immune system in rheumatoid arthritis (RA) is characterized by the production of rheumatoid factors (RF). RF are autoantibodies against the Fc part of IgG which are encoded by diverse germ-line genes. Most of the RF-encoding genes are unmutated, but in RA, a substantial quantity is encoded by somatically mutated genes. In addition, the synovial membranes (SM) of the diseased joints of RA patients are infiltrated by B lymphocytes which form germinal center-like aggregates. To analyze the local immune response, B cell foci from two RA SM were isolated by micromanipulation. From DNA of these foci, the rearranged kappa light chain variable region (V kappa) genes were amplified by polymerase chain reaction (PCR), cloned and sequenced. The amplification of different V kappa-J kappa combinations of different foci suggested oligoclonal expansion of B lymphocytes, which was confirmed by sequence analysis: each PCR product contained members of a single B cell clone. The sequence analysis of 29 different clones revealed rearrangements of diverse V kappa genes. Both frequent representatives of the V kappa 3 and the V kappa 1 family, as well as rarely used genes such as the L10 and B2 genes of the V kappa 2 and V kappa 5 families were found. Of the eleven potentially functional gene rearrangements, eight were significantly mutated, indicating their derivation from antigen-selected B cells. Intraclonal diversity in one of these clones may suggest ongoing mutation in the diseased synovial membrane of patients with RA.
体液免疫系统参与类风湿性关节炎（RA）的特征是产生类风湿因子（RF）。RF是针对IgG Fc部分的自身抗体，由多种种系基因编码。大多数编码RF的基因未发生突变，但在RA中，相当一部分是由体细胞突变的基因编码的。此外，RA患者患病关节的滑膜（SM）中有B淋巴细胞浸润，形成生发中心样聚集物。为了分析局部免疫反应，通过显微操作从两个RA滑膜中分离出B细胞灶。从这些灶的DNA中，通过聚合酶链反应（PCR）扩增重排的κ轻链可变区（Vκ）基因，进行克隆和测序。不同灶的不同Vκ-Jκ组合的扩增表明B淋巴细胞的寡克隆扩增，序列分析证实了这一点：每个PCR产物都包含单个B细胞克隆的成员。对29个不同克隆的序列分析揭示了不同Vκ基因的重排。发现了Vκ3和Vκ1家族的常见代表，以及Vκ2和Vκ5家族中很少使用的基因，如L10和B2基因。在11种潜在的功能性基因重排中，有8种发生了显著突变，表明它们源自抗原选择的B细胞。其中一个克隆的克隆内多样性可能表明RA患者患病滑膜中正在发生突变。
