WATCHING TARGET CELL OXIDATION AND CYTOLYSIS

描述：(改编自调查人员的摘要)激活人类 中性粒细胞(PMN)在慢性和急性白血病中起关键作用。 炎症过程包括传染病、感染性休克、 缺血再灌注损伤、关节炎、肾炎，可能还有对 癌症。本项目的总体目标是了解PMN的机制 激活。我们发现某些细胞表面蛋白 与补体受体3(CR3)的物理相互作用，以及 炎症相关整合素。为了充分利用这一发现，我们将 使用PMN和/或转染剂实现以下特定目标 表达天然的或基因改造的受体。我们将检验这一假设 某些糖磷脂连接的膜蛋白，如尿激酶 受体(UPAR)可逆地与CR3相互作用。实验方法 将使用对受体-受体接近和横向移动性敏感的 为了描述这些相互作用，这将与信号联系在一起 转导和细胞迁移。我们将研究CR4到UPAR的交互 并对锁相信号进行了实验测试 转导假说及其细胞起源。它的作用机制 UPAR-整合素相互作用及其生理相关性 检查过了。为了分析FcRIII-CR3相互作用的分子机制， FcRIIIB在中性粒细胞中的异型变异及表达FcRIII的转染体 通过选择删除N-连接的共有序列，将对其进行研究。我们 将使用转染体检验FcRII与CR3相互作用的假设 表达这些缺陷形式的天然蛋白质(FcRII-或CR3-) 缺乏其胞质结构域和内化能力。使用反转 遗传互补的方法，我们将测试野生型CR3的能力 或FcRII来挽救通过结扎FcRII-或CR3-介导的内化， 分别进行了分析。物理关联将使用生物物理和 免疫沉淀技术，而功能关联将是 通过跨膜信号和吞噬实验进行监测。我们的 研究将确定受体间的性质和机制 相互作用，这可能导致新的抗炎药物的开发 探员们。

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.