Desmoglein 2 Function in Cell Adhesion and Pemphigus

桥粒芯糖蛋白 2 在细胞粘附和天疱疮中的作用

• 批准号: 6653244
• 负责人: My Georgia Mahoney
• 金额: $ 7.62万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-28 至 2005-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6653244
• 关键词: age difference; autoantibody; blister; cell adhesion; cell adhesion molecules; cell growth regulation; epithelium; genetically modified animals; immunologic assay /test; intercellular connection; keratinization; laboratory mouse; laboratory rabbit; pemphigus; protein isoforms; skin; western blottings

DESCRIPTION (provided by applicant): Epidermal keratinocytes are held together by intercellular junctions called desmosomes, which are critical for the maintenance of cell-cell adhesion, tissue integrity, and organ function. Desmogleins (Dsg) are the transmembrane adhesive components of the desmosomes. In the epidermis, Dsg2 and Dsg3 are expressed in the proliferative basal keratinocytes while Dsgl is expressed in the upper differentiated cells. There is compelling evidence that desmogleins mediate cell-cell adhesion. In the human autoimmune blistering disease pemphigus, antibodies directed against Dsg1 and Dsg3 induce blister formation in the epidermis and oral mucosa. In mouse, ablation of the Dsg3 gene results in blister formation similar to that observed in pemphigus vulgaris. However, forced expression of Dsg3 in superficial epidermis where Dsg1 is expressed prevents blister formation by pemphigus foliaceus anti-Dsg1 antibodies. These data demonstrate that Dsg1 and Dsg3 play a pivotal role in epithelial cell adhesion and that one desmoglein can compensate the loss of another. The role of Dsg2 in the epidermis remains elusive in part due to its weak expression. The overall goal of this project is to elucidate the function of Dsg2 in cell adhesion in the skin. The following specific aims are proposed: 1) demonstration of pathogenic pemphigus antibodies that recognize unique epitopes on Dsg2, 2) disruption of the normal expression of Dsg2 in the epidermis, and 3) determining whether Dsg2 can compensate for the loss of Dsg1 and Dsg3. To achieve these specific aims, GST-fusion proteins of the extracellular domains of Dsg2,A,ill be used to characterize pemphigus sera by immunoblotting analysis. In addition, affinity purified Dsg2-specific pemphigus antibodies will be tested to determine specificity in relation to Dsg1 and Dsg3. Dsg2-adsorbed pemphigus antibodies will be tested by passive transfer assays for pathogenicity in neonatal mice. The function of Dsg2 in the epidermis will be studied using transgenic mice expressing Dsg2 in the superficial epidermis under control of the involucrin promoter, which has activity in cells undergoing differentiation. Such mice would provide valuable insights into the biological function of Dsg2 in the development of a functional epidermis with respect to cellular proliferation, differentiation, adhesion and bar-her functions. Finally passive transfer studies will be performed with pemphigus IgG to determine if Dsg2 can protect against anti-Dsg1 -and/or anti -Dsg3 -induced cellular acantholysis. To this end, the ultimate goal is to find a means to upregulate Dsg2 in the epidermis as a therapeutic approach to pemphigus.

描述（由申请人提供）：表皮角质形成细胞聚集在一起 通过称为桥粒的细胞间连接，这对于 维持细胞间粘附、组织完整性和器官功能。 桥粒糖蛋白 (Dsg) 是桥粒的跨膜粘附成分。 在表皮中，Dsg2和Dsg3在增殖性基底细胞中表达。 Dsgl 在上层分化细胞中表达。那里 这是桥粒芯糖蛋白介导细胞间粘附的令人信服的证据。在 人类自身免疫性水疱病天疱疮，针对 Dsg1 的抗体 Dsg3在表皮和口腔粘膜中诱导水疱形成。在小鼠中， Dsg3 基因的消融导致水泡形成，类似于观察到的情况 寻常型天疱疮。然而，Dsg3在表面的强制表达 表达 Dsg1 的表皮可预防天疱疮形成水疱 foliaceus 抗 Dsg1 抗体。这些数据表明 Dsg1 和 Dsg3 发挥作用 在上皮细胞粘附中起关键作用，一种桥粒芯糖蛋白可以 补偿他人的损失。 Dsg2 在表皮中的作用仍然存在 难以捉摸的部分原因是其表达较弱。该项目的总体目标是 阐明 Dsg2 在皮肤细胞粘附中的功能。下列 提出了具体目标：1）演示致病性天疱疮抗体 识别 Dsg2 上的独特表位，2) 破坏正常表达 表皮中 Dsg2 的表达，以及 3) 确定 Dsg2 是否可以补偿 Dsg1 和 Dsg3 的丢失。为了实现这些特定目标，GST 融合蛋白 Dsg2,A,的胞外结构域可用于表征天疱疮 通过免疫印迹分析血清。此外，亲和纯化的 Dsg2 特异性 将测试天疱疮抗体以确定相关的特异性 Dsg1 和 Dsg3。 DSG2 吸附的天疱疮抗体将通过被动测试 新生小鼠致病性转移测定。 Dsg2 的功能 将使用表达 Dsg2 的转基因小鼠来研究表皮 浅表皮在外皮蛋白启动子的控制下， 正在分化的细胞中的活性。这些小鼠将提供有价值的 深入了解 Dsg2 在细胞发育中的生物学功能 功能性表皮与细胞增殖、分化、 粘附和阻挡功能。最后被动转移研究将 使用天疱疮 IgG 进行测定，以确定 Dsg2 是否可以预防抗 Dsg1 -和/或抗-Dsg3-诱导的细胞棘层松解症。为此，最终 目标是找到一种上调表皮 Dsg2 的方法作为治疗方法 天疱疮的治疗方法。