INTERACTIONS BETWEEN INFLAMMATORY CELLS AND BASEMENT MEMBRANES

为了让炎症细胞离开血液循环进入 在肺和其他组织的血管外部位，它们必须穿过 内皮和内皮下基底膜， 细胞外基质（ECM）。在理解上取得了重大进展 中性粒细胞（PMN）和内皮细胞之间的相互作用，但相对 关于中性粒细胞和内皮下细胞之间的相互作用知之甚少 基底膜这个项目关注的是 细胞和基底膜。重点主要放在PMN上， 巢蛋白是一种完整的基底膜成分， 基底膜组件通过其与两者结合的能力， 层粘连蛋白和IV型胶原。 最近，我们报道了野生型 和重组形式的巢蛋白对PMN具有趋化性和粘附性， 被PMN释放的基质金属蛋白酶降解， 炎症细胞在这个项目中，我们将进一步定义响应 通过观察巢蛋白对PMN的影响， 吞噬活性和从PMN释放初级颗粒内容物。 我们将鉴定出负责这些作用的巢蛋白结构域和PMN受体。 entactin-PMN相互作用，定量entactin结合PMN，并研究 参与PMN信号转导反应的内陷蛋白。使用域- 特异性抗巢蛋白抗体， 我们将确定在何种情况下， 与炎性细胞相互作用的巢蛋白暴露在基底部 膜。为了扩展我们对纯巢蛋白降解的观察， 通过蛋白酶，我们将确定 组装在基膜中，被基质溶解素和其他 炎性细胞蛋白酶。为了定义细胞表达， 巢蛋白在正常肺和肺损伤组织中的分布 炎症，我们将使用分子和免疫技术， 开发模拟人类香烟烟雾诱导的肺和动物模型， 肺气肿、弥漫性肺泡损伤和纤维化肺泡炎。

In order for inflammatory cells to leave the circulation and enter extravascular sites in the lungs and other tissues, they must cross endothelium and subendothelial basement membranes composed of extracellular matrix (BCM). Major advances have occurred in understanding the interactions between neutrophils (PMN) and endothelium, but relatively little is known about interactions between PMN and the subendothelial basement membrane. This project concerns interactions between inflammatory cells and basement membranes. The focus is primarily upon PMN and entactin, an integral basement membrane component which plays a role in basement membrane assembly through its ability to bind avidly to both laminin and type IV collagen. Recently, we reported that both wild type and recombinant forms of entactin are chemotactic and adhesive for PMN and are degraded by matrix metalloproteinases released by PMN and other inflammatory cells. In this project we will define further the responses of PMN to entactin by looking at the effects of entactin upon PMN phagocytic activity and the release of primary granule contents from PMN. We will identify the entactin domains and PMN receptors responsible for entactin-PMN interactions, quantify entactin binding to PMN, and study signal transduction involved in PMN responses entactin. Using domain- specific anti-entactin antibodies that we will raise to recombinant entactin domains, we will determine the circumstances under which domains of entactin that interact with inflammatory cells are exposed in basement membranes. To extend our observations about degradation of pure entactin by proteinases, we will determine the susceptibility of entactin that is assembled in basement membranes to degradation by matrilysin and other inflammatory cell proteinases. To define the cellular expression and distribution of entactin in normal lung and in lung injured by inflammation, we will use molecular and immunologic techniques in developing lung and animal models that mimic human cigarette smoke-induced emphysema, diffuse alveolar injury, and fibrosing alveolitis.