Henry M, Zanelli E, Piechaczyk M, Pau B, Malthièry Y
Laboratoire de Biochimie Médicale, INSERM U38, Faculté de Médecine, Marseille, France.
Eur J Immunol. 1992 Feb;22(2):315-9. doi: 10.1002/eji.1830220205.
The antigenic nature of 15 anti-human thyroglobulin (hTg) monoclonal antibody (mAb) epitopes was studied by two different approaches. First, we tested two successive protease-digest products of hTg. Only four mAb from the same cluster of reactivity recognized a low-molecular weight peptide, the other mAb only bound native hTg or high-molecular weight digest fractions. Second, these 15 mAb were used to immunoscreen hTg expression libraries. Only the same four mAb revealed immunoreactive clones corresponding to region 1149-1295 on the hTg primary sequence. After subcloning, this antigenic determinant was reduced to a 102-amino acid peptide (hTg region 1149-1250). The two different methodologies were coherent and complementary, and demonstrated that hTg sequence 1149-1250 is the target for this cluster of four mAb. Moreover, anti-hTg autoantibodies which cross-reacted with these mAb bound the 102-amino acid peptide. This epitope was the one most frequently detected by sera from autoimmune thyroid disease. The data confirm the presence of an immunodominant domain in the central part of the hTg molecule and suggest that this mAb epitope may be a powerful probe for the diagnosis of autoimmune thyroid disorders.
通过两种不同方法研究了15种抗人甲状腺球蛋白（hTg）单克隆抗体（mAb）表位的抗原性质。首先，我们检测了hTg的两种连续蛋白酶消化产物。同一反应簇中的仅四种mAb识别一种低分子量肽，其他mAb仅结合天然hTg或高分子量消化片段。其次，用这15种mAb对hTg表达文库进行免疫筛选。只有相同的四种mAb揭示了与hTg一级序列上1149 - 1295区域相对应的免疫反应性克隆。亚克隆后，该抗原决定簇缩小为一个102个氨基酸的肽段（hTg区域1149 - 1250）。这两种不同方法相互连贯且互补，证明hTg序列1149 - 1250是这四种mAb反应簇的靶点。此外，与这些mAb发生交叉反应的抗hTg自身抗体结合该102个氨基酸的肽段。该表位是自身免疫性甲状腺疾病患者血清中最常检测到的表位。这些数据证实hTg分子中部存在一个免疫显性结构域，并表明该mAb表位可能是诊断自身免疫性甲状腺疾病的有力探针。
