Rahman M A, Kettleborough C A, Latchman D S, Isenberg D A
Bloomsbury Rheumatology Unit/Division of Rheumatology, Department of Medicine, University College, London, UK.
J Autoimmun. 1998 Dec;11(6):661-9. doi: 10.1006/jaut.1998.0241.
Antibodies to DNA are believed to play an important role in systemic lupus erythematosus (SLE). High affinity IgG antibodies which show marked specificity for double stranded DNA (dsDNA) are particularly closely linked to the occurrence and severity of tissue damage. Sequence analysis of mouse and human monoclonal antibodies has previously suggested that mutations in the complementarity determining regions (CDRs) play a major role in determining these binding properties. In many cases such mutations increase the overall number of basic residues in the CDRs. To further elucidate the role played by such mutations it is important to develop methods of expressing cloned autoantibody cDNA in the form of functional whole immunoglobulin molecules. We describe a system in which autoantibody VH and VL cDNA from monoclonal human anti-DNA antibodies, B3 and WRI176 were cloned into separate vectors which allowed their expression as whole heavy and whole light chains respectively. By cotransfecting mammalian cells with pairs of heavy and light chain vectors it was possible to produce whole IgG molecules from each of the four possible VH/VL combinations. Only antibody produced by homologous VH and VL pairs bound DNA, suggesting that in these autoantibodies both chains are important in conferring this property.
人们认为，针对DNA的抗体在系统性红斑狼疮（SLE）中发挥着重要作用。对双链DNA（dsDNA）具有显著特异性的高亲和力IgG抗体与组织损伤的发生和严重程度密切相关。此前，对小鼠和人类单克隆抗体的序列分析表明，互补决定区（CDR）的突变在决定这些结合特性方面起主要作用。在许多情况下，此类突变会增加CDR中碱性残基的总数。为了进一步阐明此类突变所起的作用，开发以功能性完整免疫球蛋白分子形式表达克隆自身抗体cDNA的方法很重要。我们描述了一种系统，其中来自单克隆人抗DNA抗体B3和WRI176的自身抗体VH和VL cDNA被克隆到单独的载体中，这使得它们分别作为完整的重链和完整的轻链进行表达。通过用重链和轻链载体对共转染哺乳动物细胞，有可能从四种可能的VH/VL组合中的每一种产生完整的IgG分子。只有同源VH和VL对产生的抗体结合DNA，这表明在这些自身抗体中，两条链对于赋予这种特性都很重要。
