Induction of pemphigus phenotype by a mouse monoclonal antibody against the amino-terminal adhesive interface of desmoglein 3
Induction of pemphigus phenotype by a mouse monoclonal antibody against the amino-terminal adhesive interface of desmoglein 3
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DOI：
10.4049/jimmunol.170.4.2170
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发表时间：
2003-02-15
影响因子：
4.4
通讯作者：
Amagai, M
中科院分区：
文献类型：
--
作者：
Tsunoda, K;Ota, T;Amagai, M
寻常型天疱疮（Pemphigus vulgaris， PV）是一种危及生命的自身免疫性水疱疾病，由IgG自身抗体对抗钙粘蛋白型黏附分子粘粒蛋白（Dsg）3引起。在此之前，我们已经通过过继性转移Dsg3（-/-）脾细胞建立了PV活性小鼠模型。本研究从PV小鼠模型中分离出8个AK系列抗dsg3 IgG单抗，检测其诱导水疱形成的致病活性。腹腔接种AK23杂交瘤，而不是其他AK杂交瘤，诱导的表型与PV模型小鼠或具有典型PV组织学的Dsg3（-/-）小鼠几乎相同。通过结构域交换和点突变Dsg1/Dsg3分子进行表位定位，AK23识别Dsg3上的钙依赖性构象表位，该表位由V3、K7、P8和D59 Dsg3特异性残基组成，并置Dsg之间形成粘附界面，这与晶体结构预测的一致。未显示明显致病活性的单克隆抗体的表位定位在Dsg3的中间至羧基端胞外区域，在那里没有预测直接的分子间相互作用。这些发现表明抗dsg3 IgG抗体由于其表位而具有致病异质性，并提示Dsg粘附相互作用的直接抑制是天疱疮水疱形成的初始分子事件。
Pemphigus vulgaris (PV) is a life-threatening autoinuhune blistering disease that is caused by IgG autoantibodies against the cadherin-type adhesion molecule desmoglein (Dsg)3. Previously, we have generated an active mouse model for PV by adoptive transfer of Dsg3(-/-) splenocytes. In this study, we isolated eight AK series, anti-Dsg3 IgG mAbs from the PV mouse model, and examined their pathogenic activities in induction of blister formation. Intraperitoneal inoculation of the AK23 hybridoma, but not the other AK hybridomas, induced the virtually identical phenotype to that of PV model mice or Dsg3(-/-) mice with typical histology of PV. Epitope mapping with domain-swapped and point-mutated Dsg1/Dsg3 molecules revealed that AK23 recognized a calcium-dependent conformational epitope on Dsg3, which consisted of the V3, K7, P8, and D59 Dsg3-specific residues that formed the adhesive interface between juxtaposed Dsg, as predicted by the crystal structure. The epitopes of the mAbs that failed to show apparent pathogenic activity were mapped in the middle to carboxyl-terminal extracellular region of Dsg3, where no direct intermolecular interaction was predicted. These findings demonstrate the pathogenic heterogeneity among anti-Dsg3 IgG Abs due to their epitopes, and suggest the direct inhibition of adhesive interaction of Dsg as an initial molecular event of blister formation in pemphigus.