ACTIVATION OF MACROPHAGES IN PERIODONTAL DISEASE

牙周疾病中巨噬细胞的激活

• 批准号: 3219452
• 负责人: MICHAEL J PABST
• 金额: $ 14.29万
• 依托单位: UNIVERSITY OF TENNESSEE HEALTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1994-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3219452
• 关键词: G protein; Mycobacterium tuberculosis; NAD(P)H dehydrogenase; affinity chromatography; biological signal transduction; cachexia; calcium metabolism; cholera toxin; cortisol; cyclic nucleoside monophosphate; cytochalasins; cytochrome b; cytoplasm; electron microscopy; gene expression; genetic transcription; genetic translation; glycoproteins; granuloma; human tissue; hyperthermia; inflammation; interleukin 1; lipopolysaccharides; macrophage activating factor; membrane proteins; messenger RNA; monocyte; monokines; oral bacteria; oxidoreductase; pathologic bone resorption; periodontium disorder; phospholipase A2; phospholipase C; phospholipase inhibitor; phosphorylation; physiologic bone resorption; platelet activating factor; protein kinase C; protein transport; steroid hormone; superoxides; tumor necrosis factor alpha

"Activation" or "priming" is the biochemical process that controls the ability of macrophages to produce microbicidal oxygen radicals like superoxide anion (O2-). Activated macrophages produce more O2- when they are "triggered" by microbes or by chemical stimuli like phorbol ester or f-met-leu-phe. Therefore, activated macrophages are better able to control infection. Activated macrophages also secrete more IL-1 and TNFalpha, which cause inflammation, bone resorption, fever, and cachexia. Macrophages are activated in vivo by infection, or they can be "primed" in vitro by exposure to lipopolysaccharide (LPS), muramyl dipeptide or interferon-gamma(IFN-gamma). IL-1 and TNFalpha also prime macrophages. The goal of this project is to understand the mechanisms involved in activation and priming. The first specific aim is to examine the effects of a powerful inhibitor of priming, sulfatide from Mycobacterium tuberculosis, on O2-- release and secretion of monokines in human monocytes. The purpose is to understand how a successful pathogen can block the normal priming pathway that prepares macrophages to kill bacteria. Preliminary evidence suggests that sulfatide blocks priming for enhanced O2-release by LPS and IFN-gamma, but augments secretion of IL-1beta. In this way, sulfatide may prevent the mycobacteria from being killed, while promoting granuloma formation and tissue destruction. The second aim is to investigate the receptors involved in priming by LPS. Because only a few molecules of LPS are needed to prime monocytes, detection of the LPS receptor has been difficult. The possibility that Mac-1 membrane glycoprotein is the LPS receptor will be tested using monocytes from Mac-1 deficient patients. The possibility of a plasma membrane or intracellular receptor for LPS, or for an LPS-lipoprotein complex, will be examined by electron microscopy and affinity chromatography. The third aim is to examine the signal transduction pathway controlling LPS priming. The involvement of G proteins, phospholipases and lipocortin, cytosolic Ca2+, protein phosphorylation, and translocation will be examined. The fourth aim is to examine how LPS affects the regulation of gene expression for NADPH oxidase (the enzyme system that produces O2-), and for IL-1 and TNFalpha. Cytochrome b, a membrane-associated component of NADPH oxidase, will be studied to determine if its concentration, sub-cellular distribution or participation in electron transport is affected by priming. Two cytosolic components of the oxidase will also be examined. The effect of primers and inhibitors on the transcription, stability and translation of mRNA for IL-1 and TNFalpha will be determined. Knowledge of the mechanisms involved in priming monocytes will permit development of stratagems and drugs to improve killing of pathogens by macrophages, and to suppress inflammation caused by macrophages and their products. Such agents should help to limit tissue destruction in periodontal disease and in other chronic infections and inflammatory diseases.

“激活”或“启动”是控制该过程的生化过程 巨噬细胞产生微生物氧自由基的能力 超氧化阴离子（O2-）。激活的巨噬细胞产生更多的O2- 是由微生物或化学刺激（如佛波尔酯或）“触发”的 F-met-leu-phe。因此，激活的巨噬细胞能够更好地控制 感染。激活的巨噬细胞还分泌更多的IL-1和TNFALPHA，这是 引起炎症，骨吸收，发烧和恶病质。巨噬细胞是 通过感染在体内激活，或者可以在体外“置入”体外 暴露于脂多糖（LPS），穆拉米尔二肽或 干扰素 - 伽马（IFN-gamma）。 IL-1和TNFALPHA也是主要巨噬细胞。这 该项目的目标是了解激活所涉及的机制 和启动。第一个具体目的是检查强大的效果 O2-上的结核分枝杆菌抑制剂，硫酸硫化物的硫化物 人类单核细胞中的单因子的释放和分泌。目的是 了解成功的病原体如何阻止正常的启动途径 这准备巨噬细胞杀死细菌。初步证据表明 硫化物阻止启动启动，以增强LPS和IFN-Gamma的O2释放， 但是增强了IL-1Beta的分泌。这样，亚磺胺可能会阻止 分枝杆菌在促进肉芽肿形成和 组织破坏。第二个目的是调查所涉及的受体 在LPS启动中。因为只需要几个分子来启动 单核细胞，LPS受体的检测很困难。这 Mac-1膜糖蛋白是LPS受体的可能性 使用来自MAC-1缺陷患者的单核细胞进行测试。可能性 LPS的质膜或细胞内受体或 LPS脂蛋白复合物将通过电子显微镜和 亲和色谱。第三个目的是检查信号 控制LPS启动的转导途径。 G的参与 蛋白质，磷脂酶和脂皮质素，胞质Ca2+，蛋白 将检查磷酸化和易位。第四个目标是 检查LP如何影响NADPH氧化酶的基因表达调节 （产生O2-的酶系统，以及用于IL-1和TNFALPHA。 细胞色素B是NADPH氧化酶的膜相关成分，将是 研究以确定其浓度，细胞亚分布或 参与电子传输受到启动的影响。两个胞质 还将检查氧化酶的成分。引物和 IL-1的转录，稳定性和翻译的抑制剂 将确定tnfalpha。了解涉及的机制 启动单核细胞将使策略和药物的开发 改善巨噬细胞杀死病原体，并抑制炎症 由巨噬细胞及其产品引起。这样的代理应该有助于限制 牙周疾病和其他慢性感染中的组织破坏 和炎症性疾病。