INTERACTIONS BETWEEN INFLAMMATORY CELLS AND BASEMENT MEMBRANES

为了让炎性细胞离开循环进入 肺和其他组织中的血管外部位，它们必须穿过 内皮基底膜和内皮下基底膜由 细胞外基质(BCM)。在认识上取得了重大进展 中性粒细胞(PMN)与内皮细胞的相互作用 中性粒细胞与内皮下细胞之间的相互作用知之甚少 基底膜。该项目涉及炎症性疾病之间的相互作用 细胞和基底膜。重点主要放在PMN和 Entactin，一种完整的基底膜成分，在 基底膜通过其与两者结合的能力而组装 层粘连蛋白和IV型胶原。最近，我们报道了两种野生型 重组的entactin对PMN和PMN具有趋化性和粘附性 由PMN和其他组织释放的基质金属蛋白酶降解 炎性细胞。在本项目中，我们将进一步定义响应 通过观察entactin对PMN的影响来研究PMN对entactin的影响 中性粒细胞吞噬活性和初级颗粒内容物的释放。 我们将确定entactin结构域和PMN受体负责 Entactin-PMN相互作用，定量entactin与PMN的结合，并研究 信号转导参与PMN对entactin的反应。使用域- 我们将把特定的抗牙本质蛋白抗体提高到重组 Entactin域，我们将确定域在什么情况下 与炎性细胞相互作用的entactin在基底中暴露 膜。扩大我们对纯牙本质降解的观察 通过蛋白酶，我们将确定entactin的敏感性，即 在基底膜中组装以被基质溶酶和其他物质降解 炎性细胞蛋白酶。为了定义细胞表达和 肌动蛋白在正常肺和急性肺损伤肺组织中的分布 炎症，我们将使用分子和免疫学技术 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性肺泡炎。

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.