Watts R A, Ravirajan C T, Staines N A, Isenberg D A
Department of Rheumatology Research, University College and Middlesex School of Medicine, London.
Immunology. 1990 Mar;69(3):348-54.
A human DNA-binding monoclonal antibody was produced by fusing the hepatocytes from a 12-week-old human fetus with the lymphoblastoid cell line GM 4672 using polyethylene glycol. This antibody, designated BEG 2, binds to single-stranded (ss) DNA but also binds to double-stranded (ds) DNA, poly(dT), polyI and poly(ADP-ribose), but not to RNA, cardiolipin or K-30. The binding of BEG 2 to these polynucleotides can be inhibited by incubation with polynucleotides in the fluid phase. A rabbit polyclonal anti-idiotype was raised, and using this reagent it was shown that the BEG 2 idiotype is present in normal human serum (7%), systemic lupus erythematosus (SLE) sera (8%) and rheumatoid arthritis sera (23%). The extent of idiotypic sharing between BEG 2 and murine monoclonal DNA-binding antibodies, in particular monoclonal antibody (mAb) 423 (derived from a 15-day-old fetal MRL/Mp-lpr/lpr mouse) and mAb 402 (derived from an adult MRL/lpr mouse), was also investigated. Using a competition ELISA, it was shown that preincubation of BEG 2 with rabbit anti-423 and rabbit anti-402 inhibits the binding of BEG 2 to DNA, and the binding of 402 to DNA by anti-BEG 2 and anti-423. These data suggest that mAb BEG 2, 423 and 402 share common idiotypes, that autoreactivity is present in early fetal life, and that autoantibodies may be encoded for by germline genes, which have been conserved through evolution.
通过聚乙二醇将12周龄人类胎儿的肝细胞与淋巴母细胞系GM 4672融合，制备出一种人DNA结合单克隆抗体。这种名为BEG 2的抗体可与单链（ss）DNA结合，也能与双链（ds）DNA、聚（dT）、聚I和聚（ADP - 核糖）结合，但不与RNA、心磷脂或K - 30结合。BEG 2与这些多核苷酸的结合可通过与液相中的多核苷酸孵育来抑制。制备了兔抗独特型抗体，使用该试剂表明BEG 2独特型存在于正常人血清（7%）、系统性红斑狼疮（SLE）血清（8%）和类风湿性关节炎血清（23%）中。还研究了BEG 2与鼠单克隆DNA结合抗体，特别是单克隆抗体（mAb）423（源自15日龄胎儿MRL/Mp - lpr/lpr小鼠）和mAb 402（源自成年MRL/lpr小鼠）之间独特型共享的程度。使用竞争ELISA表明，BEG 2与兔抗423和兔抗402预孵育会抑制BEG 2与DNA的结合，以及抗BEG 2和抗423对402与DNA的结合。这些数据表明mAb BEG 2、423和402共享共同的独特型，自身反应性在胎儿早期就已存在，并且自身抗体可能由种系基因编码，这些基因在进化过程中得以保留。
