Clinical and pathological significance of autoantibodies to calpastatin in rheumatoid arthritis

类风湿性关节炎中钙蛋白酶抑制剂自身抗体的临床和病理意义

基本信息

批准号：
07670540
负责人：
MIMORI Tsuneyo
金额：
$ 1.54万
依托单位：
Keio University School of Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07670540/
关键词：
autoantibody calpastatin calpain autoimmune disease rheumatoid arthritis proteinase proteinase inhibitor antigenic epitope

项目摘要

We found novel autoantibodies to calpastatin, natural inhibitor for calcium-dependent neutral proteinase (calpain), in patients with rheumatoid arthritis (RA). Since calpain is thought to be one of neutral proteinases that may be involved in joint destruction and inflammation process, the production of autoantibodies to its inhibitor protein, calpastatin, might be associated with pathogenic mechanisms of RA.In this study, we intended to elucidate 1) the clinical significance of autoantibodies ot calpastatin, 2) analysis of autoantigenic epitopes recognized by patient autoantibodies, and 3) the pathogenic role of anti-clpastatin antibodies.Autoantibodies to calpastatin in various rheumatic diseases were screened by immunoblotting using the fusion protein expressed from E.coli with a partial cDNA (RA-6) encoding the C-terminal 178 amino acids of human calpastatin. Anti-calpastatin antibodies were detected in 57% of patients with RA and were significantly more frequent than in SLE (27%), … More scleroderma (38%) and myositis (24%).Antigenic epitopes were analyzed by using an epitope library constructed by restriction enzyme-digested RA-6 cDNA that was subcloned into an expression vector. Autoantibodies from patient sera recognized a C-terminal region (C1 ; aa. 152-178) and a N-terminal region (C2 ; aa. 1-76), whereas a mouse monoclonal antibody (CSF3-3) recognized an entirely different region containing the calpain-binding site (B2 ; aa. 77-130) RA patients whose sera reacted with the Cl epitope represented a more progressed and severe state of arthritis than those not reacting with Cl.Anti-calpastatin antibodies were also detected in synovial fluids from RA patients who had anti-calpastatin in sera. IgG fractions from sera containing anti-calpastatin antibodies selectively blocked the function of calpastatin and recovered the proteolytic activity of calpain in dose-dependent manner. In contrast, IgG from normal sera or patient sera without anti-calpastatin antibodies did not recover the calpain activity.These results strongly suggest that the production of autoantibodies to calpastatin in patients with RA is not merely epiphenomenon but may be involved in pathogenic mechanisms by inhibiting the function of clpastatin and increasing the calpain activity in synovial tissue. Less

我们在类风湿关节炎（RA）的患者中发现了钙依赖性中性蛋白酶（CALPAIN）天然抑制剂的新型自身抗体，这是钙依赖性中性蛋白酶（CALPAIN）的天然抑制剂。 Since calpain is thought to be one of neutral proteinases that may be involved in joint destruction and influence process, the production of autoantibodies to its inhibitor protein, calpastatin, might be associated with pathogenic mechanisms of RA.In this study, we intended to elucidate 1) the clinical Significance of autoantibodies ot calpastatin, 2) analysis of autoantigenic epitopes recognized by patient自身抗体和3）抗clpastatin抗体的致病作用。在各种风湿性疾病中抗calpastatin抗calpastin抗体，通过使用用e.coli用e.coli表达的融合蛋白通过部分cDNA（RA-6）（RA-6）的融合蛋白进行免疫印迹，从而筛选出c-CDNA（RA-6）178 Amino amino Amino Amino Amino Amino Calpast and Calpast and Calpast。在57％的RA患者中检测到抗钙蛋白酶抗体，并且比SLE（27％）的患者更频繁地检测到……更多的硬皮病（38％）和肌炎（24％）（24％）。通过使用限制性的表演库来分析抗原性表位，该表位是通过限制性的enzyme-6 cdna构建的表演，该表演库是一个ccdna，该表现为一个ccdna，该表演量是一个ccdna。识别出C末端区域（C1；AA。152-178）和N末端区域（C2;AA。1-76）的自身抗体，而小鼠单克隆抗体（CSF3-3）则识别出一个完全不同的区域，该区域含有一个完全不同的区域，该区域含有calpain结合位点（b2; b2; b2; aa。与不与CL.-Calpastatin抗体反应的患者相比，关节炎的严重状态也被发现在血清中患有抗钙钙蛋白的RA患者的滑动液中检测到。含有抗钙钙蛋白抗体的血清中的IgG级分选择性地阻断了钙蛋白酶的功能，并以剂量依赖性方式恢复了钙蛋白酶的蛋白水解活性。相比之下，没有抗钙钙蛋白抗体的正常血清或患者血清的IgG没有恢复钙蛋白酶活性。这些结果强烈表明，RA患者在calpastatin上的自身抗体的产生不仅是epiphenomenon，而且可能通过抑制Clpastatin的功能并增加同步组织中的钙蛋白酶活性来参与致病机制。较少的