Study on the specificity and thrombogenicproperty of anficardiolipin antibodies in serafrom patients with the antiphospholipid syndrome.

1)从外周血淋巴细胞中建立9个IgM单克隆β 2-糖蛋白I （β 2- gpi）依赖性抗心磷脂抗体（aCL）。这些单克隆aCL识别的β - gpi通过与阴离子磷脂结合而发生结构改变。2)来自APS患者和具有β - gpi结构域缺失突变体的APS易感小鼠的单克隆aCL的反应性。大多数单克隆aCL被认为识别与β 2- gpi第4结构域相关的表位。3)利用GENETYX-SV/R和QUANTA/CHARMm两种分析多肽和蛋白质结构的软件，从因子H的体结构模拟人β - gpi的三维结构。4)利用抗β 2- gpi单克隆抗体搜索随机肽库，鉴定致病性aCL识别的表位。与人单克隆aCL EY1C8和EY2C9结合的多肽分别具有一致的基序。与小鼠单克隆抗人β 2- gpi抗体WBCAL-1反应的肽具有重叠的一致序列。5)为了明确抗β 2- gpi单克隆抗体识别的表位，我们在人β 2- gpi的体结构模型中寻找与鉴定出的基序相似的结构。在β 2- gpi的第4结构域上发现了EY1C8和EY2C9可能识别的表位。表位被β 2- gpi免费覆盖的第3结构域。Cof-18识别的表位位于β 2- gpi第5结构域的磷脂结合位点附近。这可能解释了Cof-18抑制β 2- gpi与阴离子磷脂的结合。

1) Nine clones of IgM monoclonal beta2-glycoprotein I (beta2-GPI) dependent anticardiolipin antibodies (aCL) were established from peripheral blood lymphocytes. These monoclonal aCL recognized beta2-GPI structurally altered by binding to anionic phospholipids.2) Reactivity of monoclonal aCL derived from patients with the APS and from APS prone mice with domain deleted mutants of beta2-GPI.Most of monoclonal aCL were considered to recognize epitope (s) related to 4th domain of beta2-GPI.3) Three dimensional structure of human beta2-GPI was analogized from the tertial structure of the Factor H,using GENETYX-SV/R and QUANTA/CHARMm, which were developed to analyze tertial structure of peptides and proteins.4) To identify the epitopes recognized by pathogenic aCL,random peptide libraries were searched with monoclonal antibodies against beta2-GPI.Peptides bound to EY1C8 and EY2C9, human monoclonal aCL,had consensus motifs respectively. Peptides reacted with WBCAL-1, a mouse monoclonal anti-human beta2-GPI antibody, had overlapping consesus sequences.5)To clarify the epitope recognized by monoclonal antibody aganist beta2-GPI,tertial structure model of human beta2-GPI was searched for structures similar to the identified motifs. The putative epitope recognized by EY1C8 and EY2C9 were identified on the 4th domain of beta2-GPI.The epitope was covered by 3rd domain in free from beta2-GPI.The epitope recognized by Cof-18 was near the phospholipid binding site on the 5th domain of beta2-GPI.This may explain the inhibition of the binding of beta2-GPI to anionic phospholipids by Cof-18.