Quorum sensing, diversity and skin inflammation

群体感应、多样性和皮肤炎症

• 批准号: 10612259
• 负责人: Richard L Gallo
• 金额: $ 11.33万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-12 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10612259
• 关键词: Animal Model; Antibiotics; Atopic Dermatitis; Bacteria; Bacterial Infections; Cells; Coagulase; Communication; Communities; Culture Media; Data; Development; Disease; Enzymes; Epithelial; Genetic; Genus staphylococcus; Goals; Growth; Health; Health Promotion; Homeostasis; Human; Immune; Immunity; In Vitro; Individual; Infection; Inflammation; Investigation; Knowledge; Microbial Biofilms; Modeling; Peptide Hydrolases; Peptide Signal Sequences; Peptides; Phenols; Play; Production; Proteins; Public Health; Publications; Regulator Genes; Regulon; Research; Resources; Role; Signal Transduction; Skin; Skin colonization; Staphylococcus aureus; Staphylococcus epidermidis; Staphylococcus haemolyticus; Staphylococcus hominis; Stratum corneum; Structure; Surface; System; Testing; Tissues; Toxin; Work; antimicrobial peptide; base; commensal bacteria; exoenzyme; immunoregulation; improved; inhibitor; innovation; insight; member; methicillin resistant Staphylococcus aureus; mutant; pathogen; prevent; quorum sensing; skin barrier; skin damage; skin disorder; skin microbiome; staphylococcal protease; synthetic peptide; transcriptome sequencing

Project Summary The surface of the skin is persistently colonized with a community of bacteria that includes numerous different species and strains of coagulase negative staphylococci (CoNS). There is mounting evidence that these CoNS prevent colonization of the skin by pathogens such Staphylococcus aureus, thereby protecting the skin from damage. Our central hypothesis is that CoNS on the skin use a peptide quorum-sensing system to limit S. aureus-induced damage to the host. All Staphylococci have a quorum-sensing system, which is also called the accessory gene regulator (agr). The agr system responds to a secreted peptide signal (autoinducing peptide or AIP), and this system controls expression of toxins and exo-enzymes from S. aureus. In CoNS, the function of the agr system is less clear, but our recent data suggest CoNS uses the agr system to survive on the skin, establish diversity, and compete against S. aureus. In support of this hypothesis, we have discovered that several common skin CoNS species produce AIP signals that inhibit the S. aureus agr system and limit skin damage. However, strain-specific knowledge of the genetic basis for this hypothesis is essential since not all CoNS strains are benefical and some can trigger inflammation. To better understand these mechanisms and their significance to human skin immune defense, in Aim 1 we will investigate whether CoNS AIP signals prevent skin damage by S. aureus. To carry out this aim, we will identify the AIP structures from culture media of selected skin CoNS strains, and test their activity as S. aureus agr inhibitors in vitro and in skin models of deep tissue infection and superficial colonization that drives skin inflammation. We will also compare CoNS and S. aureus polymicrobial interactions on the skin using explants and animal models, and assess the contribution of CoNS agr function to antimicrobial peptide production and mixed infection with S. aureus. In Aim 2, we propose that dysregulation of agr-regulated factors is a major mechanism that influences skin disease. Our preliminary studies indicate that high expression of the S. epidermidis EcpA protease promotes epidermal damage and subsequent inflammation. We will investigate S. epidermidis EcpA protease expression and the host target(s) of cleavage, and we will compare WT and mutant strains to define the impact on skin barrier disruption and inflammation. We will also investigate protective CoNS species that use AIPs to inhibit S. epidermidis EcpA production. Defining deleterious mechanisms will enable better understanding of factors favoring survival of beneficial vs harmful CoNS. In Aim 3, we will determine how CoNS use agr-regulated factors to survive on the skin. Based on our preliminary studies with S. epidermidis, we hypothesize that CoNS strains colonize the skin using the agr quorum-sensing system. We will assess the requirement of various agr-regulated loci for CoNS survival on skin and evaluate the function of identified loci for skin barrier entry. We will also determine the CoNS agr regulon using RNAseq and investigate identified targets. Collectively, the findings from the proposed work will elucidate the mechanisms used by the skin microbiome to promote health and establish homeostasis.

项目概要 皮肤表面持续定植有细菌群落，其中包括许多不同的细菌 凝固酶阴性葡萄球菌 (CoNS) 的种类和菌株。越来越多的证据表明这些 CoNS 防止金黄色葡萄球菌等病原体在皮肤上定植，从而保护皮肤免受 损害。我们的中心假设是皮肤上的 CoNS 使用肽群体感应系统来限制金黄色葡萄球菌。 金黄色葡萄球菌对宿主造成的损害。所有葡萄球菌都有群体感应系统，也称为群体感应系统 辅助基因调节因子（agr）。 agr 系统响应分泌的肽信号（自诱导肽或 AIP），该系统控制金黄色葡萄球菌毒素和外切酶的表达。在 CoNS 中，函数 agr 系统不太清楚，但我们最近的数据表明 CoNS 使用 agr 系统在皮肤上生存， 建立多样性，并与金黄色葡萄球菌竞争。为了支持这一假设，我们发现了一些 常见的皮肤 CoNS 种类产生 AIP 信号，抑制金黄色葡萄球菌 agr 系统并限制皮肤损伤。 然而，该假设的遗传基础的菌株特异性知识至关重要，因为并非所有 CoNS 菌株 是有益的，有些会引发炎症。为了更好地理解这些机制及其意义 对于人类皮肤免疫防御，在目标 1 中，我们将研究 CoNS AIP 信号是否通过以下方式预防皮肤损伤： 金黄色葡萄球菌。为了实现这一目标，我们将从选定的皮肤 CoNS 的培养基中鉴定 AIP 结构 菌株，并在体外和深部组织感染的皮肤模型中测试其作为金黄色葡萄球菌 agr 抑制剂的活性和 导致皮肤炎症的浅表定植。我们还将比较 CoNS 和金黄色葡萄球菌多种微生物 使用外植体和动物模型研究皮肤上的相互作用，并评估 CoNS agr 功能对 抗菌肽的产生和金黄色葡萄球菌的混合感染。在目标 2 中，我们建议 agr调节因子是影响皮肤病的主要机制。我们的初步研究表明 表皮葡萄球菌 EcpA 蛋白酶的高表达会促进表皮损伤和随后的炎症。 我们将研究表皮葡萄球菌 EcpA 蛋白酶的表达和裂解的宿主靶点，并且我们将 比较野生型和突变株以确定对皮肤屏障破坏和炎​​症的影响。我们还将 研究使用 AIP 抑制表皮葡萄球菌 EcpA 产生的保护性 CoNS 物种。定义有害 机制将有助于更好地了解有利于有益与有害 CoNS 生存的因素。瞄准 3、我们将确定CoNS如何利用agr调节因子在皮肤上存活。根据我们的初步研究 对于表皮葡萄球菌，我们假设 CoNS 菌株利用 agr 群体感应系统在皮肤上定殖。 我们将评估各种agr调控位点对CoNS在皮肤上存活的需求并评估其功能 确定的皮肤屏障进入位点。我们还将使用 RNAseq 确定 CoNS agr 调节子并进行研究 确定的目标。总的来说，拟议工作的结果将阐明所使用的机制 皮肤微生物群促进健康并建立体内平衡。