Lipid Effector Molecules of Innate Immunity: Antimicrobial Cholesteryl Esters

先天免疫的脂质效应分子：抗菌胆固醇酯

• 批准号: 8274652
• 负责人: EDITH PORTER
• 金额: $ 30.15万
• 依托单位: CALIFORNIA STATE UNIVERSITY LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-06 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8274652
• 关键词: Anabolism; Animal Model; Anti-Bacterial Agents; Antibiotic Resistance; Antibiotics; Bacteria; Biochemical; Biological; Biological Assay; Body Surface; Cell Wall; Cells; Cessation of life; Cholesterol Esters; Colony-Forming Units Assay; Communicable Diseases; Data; Dependence; Development; Enzymes; Epithelial; Epithelial Cells; Fatty acid glycerol esters; Haemophilus influenzae; Health; Host Defense; Human; Immune; Immune response; Immunotherapy; In Vitro; Infection; Infectious Agent; Inflammation; Inflammatory; Interleukin-17; Knowledge; Lead; Ligands; Lipids; Liquid substance; Measures; Mediating; Methodology; Microbe; Modeling; Muramidase; Natural Immunity; Nose; Operative Surgical Procedures; Pathway interactions; Pattern recognition receptor; Peptides; Positioning Attribute; Predisposition; Prevention therapy; Process; Production; Prophylactic treatment; Proteins; Pseudomonas aeruginosa; Public Health; Regulation; Relative (related person); Reporting; Research; Respiratory System; Respiratory Tract Infections; Respiratory tract structure; Reverse Transcriptase Polymerase Chain Reaction; Signal Pathway; Small Interfering RNA; Source; Staphylococcus aureus; Streptococcus pneumoniae; Structure of mucous membrane of nose; Surface; System; Technology; Testing; Time; Toll-like receptors; Virulence Factors; Work; antimicrobial; antimicrobial peptide; arm; bactericide; base; cholesteryl linoleate; chronic rhinosinusitis; cystic fibrosis patients; cytokine; disease diagnosis; in vivo; innovation; insight; microbial; neutrophil; novel; pathogen; receptor; research study; respiratory; response; synergism

DESCRIPTION (provided by applicant): Infectious diseases including respiratory infections continue to be a major health concern. In many cases infections establish when the innate mucosal defense fails. Antimicrobial peptides have been recognized as important contributors to the first line of defense. Our recent work has provided evidence that host-derived lipids represent a new class of antimicrobial effector molecules that are integral to the inherent antimicrobial activity of mucosal fluids exerting bactericidal activity alone and in synergism with antimicrobial peptides. We have further identified, for the first time, cholesteryl esters (CE's) as antimicrobial effector molecules. However, there is a major gap in knowledge with respect to the regulation of antimicrobial lipids, their mode of action, and their interaction with antimicrobial peptides. The research proposed here will answer the important questions how antimicrobial CE's are regulated in the context of infection and inflammation in the respiratory tract, which of the CE's exert most potent antibacterial activity, and how they interface with antimicrobial peptides. To identify key regulators of epithelial CE production and the most potent antibacterial CE's we will use an infection model with polarized airway epithelial cells and opportunistic respiratory tract pathogens that cause infection when the mucosal barrier function is impaired. We will assess the expression of key enzymes involved in CE biosynthesis and quantify antibacterial CE's in response to ligands for pattern recognition receptors such as bacterial cell wall products, and pro-inflammatory cytokines that act on epithelial cells, for example IL1b, IL17A. We will employ quantitative RT-PCR, biochemical analysis, and antibacterial assays. We will validate our results with primary epithelial cells established from sino-nasal mucosa obtained as surgical excess material, and confirm key regulators with siRNA methodology. We will dissect the relative contributions of antimicrobial lipids and antimicrobial peptides to the mucosal innate defense employing antibacterial assays, and bacterial challenge experiments with epithelial cells and selective inhibition of effector molecule production with siRNA technology. Upon completion of the proposed work we will be in the position to study the mode of action of antimicrobial lipids in vitro and moving into an animal model. Our study is innovative and highly significant. The lipid-arm of innate defense is an emerging concept and this research promises a high impact on public health in multiple ways. A better understanding of how to manipulate the natural production and secretion of antimicrobial lipids, in particular CE's, can lead to novel immunotherapies for infectious diseases caused by a deficiency in lipid production. The identification of antibacterial CE's and synergistically acting antimicrobial peptides may guide the development of novel lipid-antibiotics. Last, not least, this research may lead to the discovery of novel virulence factors of pathogenic microbes that circumvent host defenses mediated by antimicrobial lipids in the respiratory tract and on other mucosal surfaces.

描述（由申请人提供）：包括呼吸道感染在内的传染病仍然是主要的健康问题。在许多情况下，感染建立在先天粘膜防御失败时。抗菌肽已被认为是第一道防线的重要贡献者。我们最近的工作提供了证据，表明宿主衍生的脂质代表了一类新的抗菌效应分子，它们是粘膜液固有抗菌活性的组成部分，单独发挥杀菌活性，并与抗菌肽协同作用。我们首次进一步确定了胆固醇酯（CE’s）作为抗菌效应分子。然而，关于抗菌脂质的调节，它们的作用方式，以及它们与抗菌肽的相互作用，在知识上存在很大的差距。本文提出的研究将回答以下重要问题：在呼吸道感染和炎症的背景下，抗菌CE是如何被调节的，哪一种CE发挥最有效的抗菌活性，以及它们如何与抗菌肽结合。为了确定上皮CE产生的关键调节因子和最有效的抗菌CE，我们将使用极化气道上皮细胞和机会性呼吸道病原体的感染模型，这些病原体在粘膜屏障功能受损时引起感染。我们将评估参与CE生物合成的关键酶的表达，并量化抗菌CE对模式识别受体配体（如细菌细胞壁产物）和作用于上皮细胞的促炎细胞因子（如IL1b、IL17A）的响应。我们将采用定量RT-PCR、生化分析和抗菌试验。我们将用从鼻黏膜中获得的原代上皮细胞作为手术多余材料来验证我们的结果，并用siRNA方法确认关键调节因子。我们将通过抗菌实验、上皮细胞的细菌攻击实验和siRNA技术选择性抑制效应分子的产生来剖析抗菌脂质和抗菌肽对粘膜先天防御的相对贡献。在完成拟议的工作后，我们将能够在体外研究抗菌脂质的作用方式并进入动物模型。我们的研究具有创新性，意义重大。先天防御的脂质臂是一个新兴的概念，这项研究有望在多个方面对公众健康产生重大影响。更好地了解如何操纵抗菌脂质的自然产生和分泌，特别是CE，可以导致针对由脂质产生不足引起的传染病的新型免疫疗法。抗菌CE和协同作用抗菌肽的鉴定可能指导新型脂类抗生素的开发。最后，同样重要的是，这项研究可能会导致发现病原微生物的新的毒力因子，这些毒力因子可以绕过呼吸道和其他粘膜表面由抗菌脂质介导的宿主防御。