Chen Mei, Doostan Arvin, Bandyopadhyay Pubali, Remington Jennifer, Wang Xinyi, Hou Yingping, Liu Ziu, Woodley David T
Department of Dermatology, The Keck School of Medicine, University of Southern California, 1303 Mission Road, Los Angeles, CA 90033, USA.
Am J Pathol. 2007 Jun;170(6):2009-18. doi: 10.2353/ajpath.2007.061212.
Epidermolysis bullosa acquisita (EBA) is an acquired bullous disease of the skin characterized by IgG autoantibodies against type VII (anchoring fibril) collagen. We previously defined four immunodominant antigenic epitopes within the noncollagenous 1 (NC1) domain of type VII collagen. In this study, we produced an additional recombinant fusion protein from the NC1 domain corresponding to the N-terminal 227 amino acids (residues 1 to 227), which contains homology with cartilage matrix protein (CMP). Using enzyme-linked immunosorbent assay and immunoblot analysis, we tested sera from EBA patients (n = 32), bullous systemic lupus erythematosus patients (n = 3), bullous pemphigoid patients (n = 15), and normal humans (n = 12). Twenty-six of 32 EBA sera and two of three bullous systemic lupus erythematosus sera reacted with the CMP domain, whereas none of the control sera did. Affinity-purified anti-CMP EBA antibodies injected into hairless mice produced the clinical, histological, immunological, and ultrastructural features of EBA. F(ab')(2) fragments generated from anti-CMP EBA autoantibodies did not induce disease. Our studies provide the first evidence that EBA autoantibodies to the CMP subdomain of NC1 are pathogenic and induce blister formation. This is the first antigenic epitope on type VII collagen demonstrated to be a pathogenic target for EBA autoantibodies.
获得性大疱性表皮松解症（EBA）是一种获得性皮肤大疱病，其特征是存在针对VII型（锚定原纤维）胶原的IgG自身抗体。我们之前在VII型胶原的非胶原1（NC1）结构域内确定了四个免疫显性抗原表位。在本研究中，我们从NC1结构域中对应于N端227个氨基酸（第1至227位残基）的区域制备了一种额外的重组融合蛋白，该区域与软骨基质蛋白（CMP）具有同源性。我们使用酶联免疫吸附测定和免疫印迹分析，检测了EBA患者（n = 32）、大疱性系统性红斑狼疮患者（n = 3）、大疱性类天疱疮患者（n = 15）和正常人（n = 12）的血清。32份EBA血清中的26份以及3份大疱性系统性红斑狼疮血清中的2份与CMP结构域发生反应，而对照血清均未出现反应。将亲和纯化的抗CMP EBA抗体注射到无毛小鼠体内，可产生EBA的临床、组织学、免疫学和超微结构特征。抗CMP EBA自身抗体产生的F(ab')(2)片段不会诱发疾病。我们的研究首次证明，针对NC1的CMP亚结构域的EBA自身抗体具有致病性并可诱导水疱形成。这是VII型胶原上首个被证明是EBA自身抗体致病靶点的抗原表位。
