Byun C H, Park J Y, Akamizu T, Chae C B
Department of Life Science and Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, South Korea.
J Clin Endocrinol Metab. 2001 Jul;86(7):3311-8. doi: 10.1210/jcem.86.7.7676.
Autoantibodies against TSH receptor (TSHR) are known to be involved in the occurrence of Graves' disease. It is obvious that mapping of epitopes of the autoantibodies found in the patients with Graves' disease is an important step in elucidating possible mechanism of generation of the autoantibodies against TSHR as well as in developing effective diagnostic and therapeutic approaches for Graves' disease. In this report we have identified the peptide sequences that bind to two human monoclonal thyroid-stimulating antibodies (mTSAbs; B6B7 and 101-2) from a disulfide-constrained phage-displayed peptide library. The peptides selected by three rounds of biopanning showed half-maximal inhibitory activities for cAMP synthesis induced by mTSAbs at about 0.1 micromol/L. SPWTLGA and TQWNMQH selected for B6B7 and 101-2, respectively, show specificity for their respective antibodies. This means that different clones of mTSAbs may have different epitopes for TSHR. The IgG of the patient from whom B6B7 was derived binds with specificity to the respective immobilized peptide in an enzyme-linked immunosorbant assay format, and its cAMP generation was also inhibited by selected peptide. It may be possible that the epitopes of TSAbs identified from the phage-displayed peptide library could be used for the classification of different clones of TSAbs present in patients with Graves' disease and for development of drugs to treat Graves' disease.
已知针对促甲状腺激素受体（TSHR）的自身抗体与格雷夫斯病的发生有关。显然，确定格雷夫斯病患者体内发现的自身抗体的表位图谱，对于阐明针对TSHR的自身抗体产生的可能机制以及开发针对格雷夫斯病的有效诊断和治疗方法而言，是重要的一步。在本报告中，我们从一个二硫键约束的噬菌体展示肽库中鉴定出了与两种人源单克隆促甲状腺抗体（mTSAbs；B6B7和101-2）结合的肽序列。经过三轮生物淘选筛选出的肽，对mTSAbs诱导的cAMP合成表现出约0.1微摩尔/升的半数最大抑制活性。分别为B6B7和101-2筛选出的SPWTLGA和TQWNMQH，对各自的抗体具有特异性。这意味着mTSAbs的不同克隆可能对TSHR具有不同的表位。源自B6B7的患者的IgG在酶联免疫吸附测定形式中与各自固定化的肽特异性结合，并且其cAMP生成也受到所选肽的抑制。从噬菌体展示肽库中鉴定出的TSAbs表位，有可能用于对格雷夫斯病患者体内存在的不同TSAbs克隆进行分类，以及用于开发治疗格雷夫斯病的药物。
