Atta M S, Powell R J, Hopkinson N D, Todd I
Immunology Department, Queen's Medical Centre, Nottingham, UK.
Clin Exp Immunol. 1994 Apr;96(1):20-5. doi: 10.1111/j.1365-2249.1994.tb06223.x.
Sera from patients with connective tissue diseases exhibit autoantibodies to a spectrum of extracellular matrix proteins. Antibodies binding to solid phase bovine fibronectin (Fn) were investigated by ELISA in patients with systemic lupus erythematosus (SLE). Sera showing binding of 2 s.d. above the mean of the normal human control were considered positive and 43/150 SLE sera (28.7%) demonstrated such binding. These antibodies were mainly IgG and IgA as determined by isotype-specific ELISA. Specificity studies on selected positive sera revealed that binding was inhibited by preincubation with soluble Fn, but not with thyroglobulin or type 1 collagen. The binding was demonstrated not to be related to interactions with rheumatoid factor, complement components or immune complexes. Additional studies to determine which Fn fragment is bound by naturally occurring anti-Fn antibodies demonstrated that the binding was predominantly to the 30-kD collagen binding domain (CBD) of Fn molecule. Inhibition studies using 120-kD, 40-kD and 30-kD Fn fragments confirmed that this binding site was the 30-kD CBD.
结缔组织病患者的血清中存在针对一系列细胞外基质蛋白的自身抗体。通过酶联免疫吸附测定（ELISA）研究了系统性红斑狼疮（SLE）患者血清中与固相牛纤连蛋白（Fn）结合的抗体。与正常人对照平均值相比，结合值高于均值2个标准差的血清被视为阳性，150份SLE血清中有43份（28.7%）呈现出这种结合。通过同型特异性ELISA测定，这些抗体主要为IgG和IgA。对选定阳性血清的特异性研究表明，与可溶性Fn预孵育可抑制结合，但与甲状腺球蛋白或I型胶原预孵育则不能。已证实这种结合与类风湿因子、补体成分或免疫复合物的相互作用无关。为确定天然存在的抗Fn抗体结合Fn的哪个片段而进行的其他研究表明，这种结合主要针对Fn分子的30-kD胶原结合域（CBD）。使用120-kD、40-kD和30-kD Fn片段进行的抑制研究证实，该结合位点为30-kD CBD。
