WATCHING TARGET CELL OXIDATION AND CYTOLYSIS

描述：（改编自研究者摘要）人类激活 多形核白细胞（PMN）在慢性和急性炎症中起着关键作用。 炎症过程，包括传染病、脓毒性休克， 缺血-再灌注损伤、关节炎、肾炎，可能还有对 癌 该计划的总体目标是了解PMN的机制 activation. 我们发现某些细胞表面蛋白 与3型补体受体（CR 3）发生物理相互作用， 炎症相关整合素。 为了利用这一发现，我们将 使用PMN和/或转染子解决以下具体目标 表达天然或工程化受体。 我们将检验这个假设， 某些糖磷脂连接的膜蛋白，如尿激酶 受体（uPAR），可逆地与CR 3相互作用。 实验方法 将使用对受体-受体接近和横向移动敏感的 来表征这些相互作用，这将与信号 转导和细胞迁移。 我们将研究CR 4与uPAR的相互作用 并提供锁相信号的实验测试 转导假说及其细胞起源。 的机理 uPAR-整联蛋白相互作用及其生理相关性将被 考察 为了分析FcRIII-CR 3相互作用的分子机制， 中性粒细胞和表达FcRIII的转染子中FcRIIIB的同种异型变体 将研究N-连接共有序列的选择性缺失。 我们 将使用转染子检验FcRII与CR 3相互作用的假设 其表达这些缺陷形式的天然蛋白质（FcRII-或CR 3-）， 缺乏其胞质结构域和内化能力。 使用反向 基因互补方法，我们将测试野生型CR 3的能力， 或FcRII来拯救由FcRII-或CR 3-连接介导的内化， 分别 物理关联将使用生物物理和 免疫沉淀技术，而功能协会将是 使用跨膜信号传导和吞噬测定监测。 我们 研究将确定受体间的性质和机制 相互作用，这可能会导致新的抗炎药的开发 剂.

DESCRIPTION: (Adapted from the investigator's abstract) Activation of human polymorphonuclear leukocytes (PMN) plays a key role in chronic and acute inflammatory processes including infectious disease, septic shock, ischemia-reperfusion injury, arthritis, nephritis, and perhaps resistance to cancer. This program's overall goal is to understand the mechanism of PMN activation. We have discovered that certain cell surface proteins physically interact with complement receptor type 3 (CR3), an inflammation-associated integrin. To capitalize on this finding, we will address the following specific aims using PMNs and/or transfectants expressing native or engineered receptors. We will test the hypothesis that certain glycophospholipid-linked membrane proteins, such as urokinase receptors (uPAR), reversibly interact with CR3. Experimental methods sensitive to receptor-receptor proximity and lateral mobility will be used to characterize these interactions, which will be linked with signal transduction and cell migration. We will examine CR4-to uPAR interactions on PMNs and provide experimental tests of the phase-locked signal transduction hypothesis and its cellular origin. The mechanism of uPAR-integrin interactions and their physiological relevance will be examined. To analyze the molecular mechanism of FcRIII-CR3 interaction, allotypic variants of FcRIIIB in PMNs and transfectants expressing FcRIII with selected deletion of N-linked consensus sequences will be studied. We will test the hypothesis that FcRII interacts with CR3 using transfectants that express these native proteins of defective forms (FcRII- or CR3-) that lack their cytoplasmic domains and internalization ability. Using a reverse genetic complementation approach, we will test the ability of wild-type CR3 or FcRII to rescue internalization mediated by ligation of FcRII- or CR3-, respectively. Physical association will be studied using biophysical and immunoprecipitation techniques whereas functional associations will be monitored using transmembrane signaling and phagocytosis assays. Our studies will determine the nature and mechanisms of inter-receptor interactions, which may lead to the development of new anti-inflammatory agents.