RECEPTORS AND TRANSDUCTION MECHANISMS IN HUMAN PHAGOCYTES

人类吞噬细胞的受体和转导机制

• 批准号: 3809668
• 负责人: H L MALECH
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3809668
• 关键词: Anura; NAD(P)H dehydrogenase; adenosine triphosphate; bactericidal immunity; biological signal transduction; calcium flux; cellular respiration; chemotaxis; chlorine; complement; complement receptor; cytochrome b; eosinophil; gene expression; genetic transcription; glycosylation; guanine nucleotide binding protein; human subject; inflammation; ion transport; membrane proteins; monocyte; neutrophil; peptides; phagocytes; phagocytosis; platelet activating factor; protein structure function; receptor; superoxides; tissue /cell culture

This project defines the biochemical structure and function of receptors, transduction proteins and the NADPH oxidase effector system involved in human neutrophil and monocyte responses to inflammation and infection. Studies focus upon: (i) chemotactic receptors for formyl peptides (FPCR), C5a, platelet activating factor (PAF) and ATP (P2); and (ii) NADPH oxidase components in the cytosol p47-phox, p67-phox, NCF-3 and the membrane cytochrome b558 (CYTO b) subunits P22-phox and gp9l-phox mediating microbicidal superoxide production. Using myeloid cell mRNA in a frog oocyte expression system we demonstrate chloride currents and calcium effluxes in response to FMLP, C5a, PAF, and ATP. These responses are mediated by mRNA transcripts of 2 kb for FMLP and C5a receptors and 4 and 6 kb for PAF and ATP. FMLP, C5a and ATP responses are pertussis toxin sensitive (mediated by G-protein) while PAF responses are not. We are the first to delineate and clone cDNA encoding two neutrophil cytosol factors p47-phox and p67-phox essential to NADPH oxidase activation. Both proteins contain a pair of homologous sequences with similarity to the src-oncogene SH3 (A-box) regulatory region. We show that p47-phox undergoes a series of phosphorylations culminating in the interaction of p47 with a distinct amino acid sequence (RGVHFIF) present in the cytoplasmic domain of cytochrome b558 gp9l subunit. This is followed by translocation of other cytoplasmic oxidase components to the membrane and activation of the oxidase. Using a baculovirus expression system, active recombinant p47-phox and p67-phox have been used to demonstrate the absolute requirement for a third cytoplasmic factor, NCF-3, for activation of the oxidase.

该项目定义了受体的生化结构和功能， 转导蛋白和参与的NADPH氧化酶效应系统 人类中性粒细胞和单核细胞对炎症和感染的反应。 研究重点是：（i）甲基肽（FPCR）的趋化受体， C5a，血小板激活因子（PAF）和ATP（P2）； （ii）NADPH氧化酶 细胞质P47-Phox，p67-Phox，NCF-3和膜中的成分 细胞色素B558（Cyto B）亚基P22-Phox和GP9L-Phox介导 微生物超氧化物的产生。在青蛙中使用髓样细胞mRNA 卵母细胞表达系统我们证明氯水流和钙 响应FMLP，C5A，PAF和ATP的排出。这些反应是 由FMLP和C5A受体的2 kb的mRNA转录物以及4和6介导 KB用于PAF和ATP。 FMLP，C5A和ATP响应是百日咳毒素 敏感（由G蛋白介导）而PAF响应不是。我们是 首先描述和克隆cDNA编码两个中性粒细胞胞质因子 NADPH氧化酶活性必不可少的P47-PHOX和P67-PHOX。两种蛋白质 包含一对与SRC-癌基因相似的同源序列 SH3（A-Box）监管区域。我们表明p47-phox经历了一系列 磷酸化最终导致p47的相互作用与不同的相互作用 存在于细胞质结构域中的氨基酸序列（RGVHFIF） 细胞色素B558 GP9L亚基。接下来是其他人的易位 细胞质氧化酶成分到膜和激活 氧化酶。使用杆状病毒表达系统，主动重组P47-Phox 和p67-phox已被用来证明A的绝对要求 第三个细胞质因子NCF-3，用于激活氧化酶。