ANTIMICROBIAL EFFECT OF PEROXIDASE - ROLE IN LEUKOCYTES

过氧化物酶的抗菌作用 - 在白细胞中的作用

• 批准号: 3124386
• 负责人: SEYMOUR J KLEBANOFF
• 金额: $ 13.29万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-06-01 至 1988-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3124386
• 关键词: Mycobacterium leprae; antiinfective agents; autoradiography; bacterial cytopathogenic effect; bactericidal immunity; chemotaxis; cytotoxicity; electron microscopy; gel electrophoresis; human subject; immune tolerance /unresponsiveness; leukocytes; peroxidases; phagocytes; phagocytosis; superoxides

We propose to study the properties, mechanism of action and biological significance the oxygen-dependent antimicrobial systems of phagocytes. Phagocytes respond to perturbation of the plasma membrane with a burst of oxygen consumption and extra oxygen consumed is converted to the superoxide anion, hydrogen peroxide, hydroxyl radicals and possible singlet oxygen, each of which may contribute to themicrobicidal activity of the cells. the toxicity of H2O2 is increased considerably by the addition of peroxidase and a halide and this antimicrobial system appears to play a role in certain phagocytes (e.g. neutrophils, monocytes). Our aim is to determine the mechanism of target cell destruction by these antimicrobial systems with emphasis on the oxidation of iron centers with the release of iron into the medium. Intact organisms, membrane vesicles or model iron-containing compounds will be exposed to isolated antimicrobial systems and, in some instances, to intact phagocytes. The organisms will be prelabeled with 59Fe, and polyacrylamide gel electrophoresis, radioautography and histochemical staining will be employed to identify the proteins primarily affected. The binding of the released iron by lactoferrin will be investigated since this iron-binding protein is present in neutrophil granules and may serve as a biological chelator of the iron in situ. The properties of a new iron-containing antimicrobial system consisting of iron, H2O2 and iodide will be investigated with emphasis on the usefulness of this system for the disinfection of water of organisms which induce diarrhea (e.g. Giardia cysts). A study of the susceptibility of the intracellular pathogen Mycobacterium leprae to the antimicrobial systems of phagocytes will be undertaken in an attempt to determine the basis for their host resistance. A microscopic and metabolic method for the rapid detection of viability of M leprae will be evaluated. Neutrophil function of selected patients with an increased susceptibility to infectionwill be evaluated in an attempt to elucidate the basis for the dysfunction. The long term goals are 1) to determine the role of these systems in the killing of microorganisms by phagocytes; 2) to determine whether alterations in these systems contribute to the pathogenesis of disease; and 3) to determine whether manipulations of these systems influence the course of disease.

我们建议研究的性质，作用机制和生物 吞噬细胞的氧依赖性抗菌系统的重要性。 吞噬细胞对质膜的扰动作出反应， 氧气消耗和额外消耗的氧气转化为超氧化物 阴离子、过氧化氢、羟基自由基和可能的单线态氧， 每一种都可能有助于细胞的杀微生物活性。 的 过氧化物酶的加入大大增加了H2 O2的毒性 和卤化物，这种抗菌系统似乎在 某些吞噬细胞（如中性粒细胞、单核细胞）。 我们的目标是确定 这些抗微生物系统破坏靶细胞的机制 重点是铁中心的氧化和铁的释放 进入介质。 完整生物体、膜囊泡或模型 含铁化合物将暴露于隔离的抗微生物系统 并且在某些情况下，对完整的吞噬细胞。 这些生物体将 59 Fe预标记，聚丙烯酰胺凝胶电泳， 放射自显影和组织化学染色将用于识别 蛋白质主要受到影响。 释放的铁被 将研究乳铁蛋白，因为存在这种铁结合蛋白 在中性粒细胞颗粒中，可作为铁的生物螯合剂 在原地。 一种新型含铁抗菌体系的性能 由铁，H2 O2和碘化物将重点研究 该系统用于生物体的水消毒的有用性 引起腹泻（例如贾第虫囊肿）。 易感性研究 胞内病原体麻风分枝杆菌对抗菌药物 系统的吞噬细胞将进行尝试，以确定 是宿主抵抗力的基础。 一种显微镜和代谢方法， 将评价麻风菌活力的快速检测。 中性粒 功能的选定患者的易感性增加 感染将被评估，试图阐明的基础上， 功能障碍 长期目标是：（1）确定 系统在杀死微生物的吞噬细胞; 2），以确定 这些系统的改变是否有助于 疾病;和3）以确定是否操纵这些系统 影响疾病的进程。