CFTR Expression and Function in Human Neutrophils

CFTR 在人中性粒细胞中的表达和功能

基本信息

批准号：
7320033
负责人：
GUOSHUN WANG
金额：
$ 36.54万
依托单位：
LSU HEALTH SCIENCES CENTER
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-09-01 至 2011-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7320033
关键词：
Accounting Affect Anions Azurophilic Granule Bacteria Biological Assay Candida albicans Caucasians Caucasoid Race Cell membrane Cells Chloride Channels Chloride Ion Chlorides Cyclic AMP Cystic Fibrosis Cystic Fibrosis Transmembrane Conductance Regulator Cytoplasmic Granules Data Defect Electrons Ensure Enzymes Epithelial Cells Escherichia coli Functional disorder Gelatinases Genes Goals Haemophilus influenzae Hereditary Disease Human Hydrogen Peroxide Hypochlorous Acid Hypochlorous Acids Immunoblotting Incubated Invaded Knowledge Label Laboratories Latex Bead Learning Life Link Magnetism Measures Mediating Microscopic Molecular Mutation Nitrogen Occupations Organelles Organism Oxidants Oxidases Pathway interactions Permeability Peroxidase Phagocytes Phagocytosis Phagolysosome Phagosomes Play Pneumonia Production Property Pseudomonas aeruginosa Publications Reaction Regulation Research Personnel Resistance Rest Role Role playing therapy Secretory Vesicles Serum Staining method Stains Staphylococcus aureus Subcellular Fractions Testing Vesicle Weight Zymosan antimicrobial antimicrobial peptide base chlorination cystic fibrosis patients inhibitor/antagonist killings microbial microbicide microorganism neutrophil novel pathogen programs

项目摘要

DESCRIPTION (provided by applicant): Neutrophilic polymorphonuclear leukocytes (PMNs or neutrophils), the main phagocytes responsible for elimination of pathogens and cell debris, synthesize and maintain abundant myeloperoxidase (MPO). This special oxidase converts hydrogen peroxide and chloride anion to hypochlorous acid (HOCI), one of the most potent oxidants for bacterial killing. Even though this reaction can occur extracellularly if MPO is secreted or leaked out, it is largely contained within PMN phagolysosomes. Our preliminary data and publication have demonstrated that cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP- regulated chloride channel, is expressed in neutrophils and their phagolysosomes. Importantly, the gene defects in PMNs from cystic fibrosis (CF) patients have an impaired HOCI production in phagolysosomes. Such a deficiency affects the chlorination and killing of phagocytosed bacteria. Based on these findings, we hypothesize that CFTR plays a pivotal role in regulating chloride levels in phagolysosomes. Therefore, a dysfunctional CFTR in CF may affect the chloride availability to this organelle, thus compromising the bacterial killing capacity of the PMNs. The long-term objective of this proposal is to confirm CFTR expression in PMNs and its function in chloride secretion to phagolysosomes. We put forward four specific aims: 1) to identify the subcellular localization of CFTR in resting neutrophils from normal subjects and CF patients; 2) to characterize CFTR function in isolated phagolysosomes from normal and CF neutrophils; 3) to examine the role of CFTR in regulation of phagolysosomal chloride concentration in live neutrophils; and 4) to compare the microbicidal abilities of normal, CF and MPO-deficient neutrophils. By completion of the four specific aims, we will understand the importance of CFTR in secretion of chloride anion to phagolysosomes. Such studies will extend our current understanding of the role played by CFTR in non-epithelial cells and establish the link of a dysfunctional chloride channel function with the neutrophil bacterial killing capacity. Apparently, the obtained knowledge is highly relevant to searching effective therapies for the treatment of CF, the most fatal genetic disease in Caucasians.

描述（由申请人提供）：中性粒细胞（PMN 或中性粒细胞）是负责消除病原体和细胞碎片的主要吞噬细胞，合成并维持丰富的髓过氧化物酶（MPO）。这种特殊的氧化酶将过氧化氢和氯阴离子转化为次氯酸 (HOCI)，次氯酸是杀菌最有效的氧化剂之一。尽管如果 MPO 分泌或漏出，这种反应可以在细胞外发生，但它主要包含在 PMN 吞噬溶酶体内。我们的初步数据和出版物表明，囊性纤维化跨膜电导调节因子（CFTR）是一种 cAMP 调节的氯离子通道，在中性粒细胞及其吞噬溶酶体中表达。重要的是，囊性纤维化 (CF) 患者的 PMN 中的基因缺陷导致吞噬溶酶体中 HOCI 的产生受损。这种缺陷会影响被吞噬细菌的氯化和杀灭。基于这些发现，我们假设 CFTR 在调节吞噬溶酶体中的氯水平方面发挥着关键作用。因此，CF 中功能失调的 CFTR 可能会影响该细胞器的氯化物可用性，从而损害 PMN 的细菌杀灭能力。该提案的长期目标是确认 PMN 中的 CFTR 表达及其在氯化物分泌到吞噬溶酶体中的功能。我们提出了四个具体目标：1）确定CFTR在正常受试者和CF患者的静息中性粒细胞中的亚细胞定位； 2) 表征从正常和 CF 中性粒细胞分离的吞噬溶酶体中的 CFTR 功能； 3) 检查CFTR在调节活中性粒细胞中吞噬溶酶体氯化物浓度中的作用； 4) 比较正常、CF 和 MPO 缺陷的中性粒细胞的杀菌能力。通过完成四个具体目标，我们将了解 CFTR 在氯离子分泌到吞噬溶酶体中的重要性。此类研究将扩展我们目前对 CFTR 在非上皮细胞中所发挥作用的理解，并建立功能失调的氯离子通道功能与中性粒细胞杀伤能力之间的联系。显然，所获得的知识对于寻找治疗 CF（白种人中最致命的遗传病）的有效疗法高度相关。