Fang Q, Kannapell C C, Gaskin F, Solomon A, Koopman W J, Fu S M
Department of Medicine, University of Virginia School of Medicine, Charlottesville 22908.
J Exp Med. 1994 May 1;179(5):1445-56. doi: 10.1084/jem.179.5.1445.
To determine the molecular and functional properties of human rheumatoid factors (RF), we established stable hybridomas and Epstein-Barr virus-transformed B cell lines from the synovial fluid or peripheral blood of three patients with rheumatoid arthritis and one patient with systemic lupus erythematosus. 17 cell lines were obtained that produced high-titer immunoglobulin M (IgM) RF that reacted exclusively with rabbit but not human IgG or IgG of other mammalian species. Certain anti-rabbit IgG RF also had specificity for other mammalian antigens (Ag), including cytoskeletal proteins and intracellular proteins found in HeLa cells, as well as for Ag present in an extract prepared from the cell wall of group A streptococci. 13 of the 17 RF contained lambda-type light (L) chains, of which 12 were classified serologically as members of the lambda-L chain variable region (V lambda) subgroup, designated V lambda III. The heavy chain V region (VH) and V lambda sequences of nine of these IgM lambda RF were determined at the cDNA level. Five VH genes in three VH families were used by these antibodies (Ab), including VH1 (dp21/1-4b and dp10 [51p1]/hv1051), VH3 (dp38/3-15 and dp77/13-21), and VH4 (dp70/4-4b). The deduced V gene-encoded amino acid sequences of the lambda chains of these IgM lambda RF confirmed their serological classification as lambda III, and they were further classified as members of the relatively uncommon V lambda III subgroup, designated V lambda IIIb. Based on cDNA analyses, nine were the product of three different V lambda III b germline genes. Two such genes, designated hsiggll150 and hsiggll295, were cloned and sequenced from genomic DNA. Unique combinations of these VH and V lambda III b genes could be related to distinctive patterns of reactivity among the IgM lambda RF. Although the VH and V lambda regions of these Abs were expressed primarily as germline-encoded sequences, four of nine multireactive Abs had extensive V region mutation, indicative of an Ag-driven process. The finding that lambda IIIb L chains are preferentially found among anti-rabbit IgG RF, and that some of these Ab have specificity for other protein, cellular, and bacterial Ag, provides new insight into the pathogenesis of RA and related diseases.
为了确定人类类风湿因子（RF）的分子和功能特性，我们从三名类风湿性关节炎患者和一名系统性红斑狼疮患者的滑液或外周血中建立了稳定的杂交瘤和爱泼斯坦 - 巴尔病毒转化的B细胞系。获得了17个细胞系，它们产生高滴度免疫球蛋白M（IgM）RF，该RF仅与兔IgG反应，而不与人或其他哺乳动物物种的IgG反应。某些抗兔IgG RF对其他哺乳动物抗原（Ag）也具有特异性，包括HeLa细胞中发现的细胞骨架蛋白和细胞内蛋白，以及从A组链球菌细胞壁制备的提取物中存在的Ag。17个RF中的13个含有λ型轻（L）链，其中12个在血清学上被分类为λ-L链可变区（Vλ）亚组的成员，命名为VλIII。这些IgMλRF中的九个的重链V区（VH）和Vλ序列在cDNA水平上被确定。这些抗体（Ab）使用了三个VH家族中的五个VH基因，包括VH1（dp21/1-4b和dp10 [51p1]/hv1051）、VH3（dp38/3-15和dp77/13-21）和VH4（dp70/4-4b）。这些IgMλRF的λ链推导的V基因编码氨基酸序列证实了它们在血清学上分类为λIII，并且它们进一步被分类为相对不常见的VλIII亚组的成员，命名为VλIIIb。基于cDNA分析，九个是三个不同的VλIIIb种系基因的产物。从基因组DNA中克隆并测序了两个这样的基因hsiggll150和hsiggll295。这些VH和VλIIIb基因的独特组合可能与IgMλRF之间不同的反应模式有关。尽管这些Ab的VH和Vλ区域主要作为种系编码序列表达，但九个多反应性Ab中的四个具有广泛的V区突变，表明是一个抗原驱动的过程。在抗兔IgG RF中优先发现λIIIb L链，并且其中一些Ab对其他蛋白质、细胞和细菌Ag具有特异性，这一发现为类风湿性关节炎和相关疾病的发病机制提供了新的见解。
