Elagib K E, Børretzen M, Thompson K M, Natvig J B
Institute of Nuclear Medicine and Molecular Biology, University of Gezira, Wad Medani, Sudan.
Scand J Immunol. 1999 Nov;50(5):492-8. doi: 10.1046/j.1365-3083.1999.00624.x.
We have characterized and sequenced the variable (V) region genes of the light (L) chains of 10 immunoglobulin (IgM) rheumatoid factor (RF) monoclonal antibodies (MoAb) derived by the hybridoma/Epstein-Barr virus (EBV) technique from the peripheral blood of patients with primary Sjögren's syndrome (pSS). Six out of 10 RFs used lambda (lambda) L chains, while four RFs used kappa (kappa) L chains. Five out of the six lambda RFs were encoded by Vlambda3 gene segments, the sixth one was encoded by a Vlambda1 gene segment. This preferential utilization of the Vlambda3 family genes suggests selective expansion of the B cell in pSS. Three of the kappa RFs used Vkappa3 gene segments, while the fourth used a Vkappa2 gene segment. Half of the RFs were found as unmutated copies of their closest germline (GL) gene. Interestingly these RFs were previously shown to use heavy (H) chains in GL gene configuration. Three RFs have very few mutations (2-3) and only two RFs have substantial numbers of mutations (6 and 11). This also correlated with the number of mutations in the respective H chains. In contrast to RFs in normal and RA these results further suggest the somatic mutation to be of moderate importance in the generation of RF from the peripheral blood of pSS patients.
我们已对通过杂交瘤/爱泼斯坦-巴尔病毒（EBV）技术从原发性干燥综合征（pSS）患者外周血中获得的10种免疫球蛋白（IgM）类风湿因子（RF）单克隆抗体（MoAb）轻链（L链）的可变（V）区基因进行了表征和测序。10种RF中有6种使用λ（lambda）L链，而4种RF使用κ（kappa）L链。6种λRF中有5种由Vlambda3基因片段编码，第6种由Vlambda1基因片段编码。Vlambda3家族基因的这种优先利用表明pSS中B细胞的选择性扩增。4种κRF中有3种使用Vkappa3基因片段，而第4种使用Vkappa2基因片段。发现一半的RF是其最接近的种系（GL）基因的未突变拷贝。有趣的是，这些RF先前已显示在GL基因构型中使用重链（H链）。3种RF的突变很少（2 - 3个），只有2种RF有大量突变（6个和11个）。这也与各自H链中的突变数量相关。与正常人和类风湿关节炎（RA）中的RF不同，这些结果进一步表明体细胞突变在pSS患者外周血中RF的产生中具有中等重要性。
