DOMINANT NEGATIVE PDGF RECEPTORS IN AIRWAY FIBROSIS

闭塞性毛细支气管炎是一种纤维增生性疾病。 肺移植后间充质细胞和它们的 结缔组织产物在小气道内积聚，导致 进行性气流阻塞，致残，常常死亡。这种病 被认为是由于免疫介导的呼吸道上皮损伤 启动一种不受控制的纤维增殖反应。血小板源 生长因子(PDGF)，指导迁移和复制的一部分 间充质细胞，已经强烈地牵涉到几个 纤维增生性肺疾病，包括OB。我们假设 抑制PDGF可以限制呼吸道内纤维的增殖 在肺移植后。这项提案旨在阻止 该配体通过转染法在移植气管内的局部作用 血小板衍生生长因子受体显性负性突变体在哮喘动物模型中的作用 移植纤维化。要做到这一点，我们将1)创建一系列 PDGF受体全长c DNA缺失突变体的构建及检测 这些突变体具有与配体结合的能力，并作为显性 2)开发一种基因转移系统，使其能够 突变受体在呼吸道上皮细胞中的高效表达 使用腺病毒载体，3)检测显性阴性PDGF 受体在动物模型中抑制纤维增殖的能力 移植后的呼吸道纤维化。

Obliterative bronchiolitis (OB) is a fibroproliferative disorder seen following lung transplantation in which mesenchymal cells and their connective tissue products accumulate within small airways, causing progressive airflow obstruction, disability and often death. This disease is thought to be due to an immune mediated airway epithelial injury which initiates an uncontrolled fibroproliferative response. Platelet-derived growth factor (PDGF), a moiety which directs the migration and replication of mesenchymal cells, has been strongly implicated in several fibroproliferative pulmonary disorders, including OB. We hypothesize that inhibition of PDGF can limit the fibroproliferation within airways seen following lung transplantation. This proposal seeks to interdict the action of this ligand locally within transplanted airways by transfecting a dominant negative mutant PDGF receptor to airways of an animal model of transplant fibrosis. To accomplish this, we will 1) create a series of PDGF receptor deletion mutants from full length receptor cDNA, and test these mutants for ability to bind ligand and function as a dominant negative in vitro; 2) develop a gene transfer system which allows efficient expression of the mutant receptor in airway epithelium by utilizing an adenovirus vector, and 3) test the dominant negative PDGF receptor for its ability to inhibit fibroproliferation in an animal model of transplant airway fibrosis.