Quorum sensing, diversity and skin inflammation

群体感应、多样性和皮肤炎症

• 批准号: 10411990
• 负责人: Richard L Gallo
• 金额: $ 59.52万
• 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/10411990
• 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.

项目摘要 皮肤的表面持续地与包括许多不同不同的细菌群落殖民 凝固酶阴性葡萄球菌的物种和菌株（CONS）。有越来越多的证据表明这些缺点 防止病原体这样的金黄色葡萄球菌将皮肤定殖，从而保护皮肤免受 损害。我们的中心假设是，皮肤上的缺点使用肽群体感应系统来限制S。 金黄色葡萄球菌引起的宿主损坏。所有葡萄球菌都有一个法定感应系统，也称为 辅助基因调节剂（AGR）。 AGR系统对分泌的肽信号（自动诱导肽或 AIP），该系统控制来自金黄色葡萄球菌的毒素和外酶的表达。在缺点，功能 AGR系统不太清楚，但是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，我们发现有几个 常见的皮肤缺陷物种产生AIP信号，可抑制金黄色葡萄球菌AGR系统并限制皮肤损伤。 但是，该假设的遗传基础特定于应变的知识至关重要，因为并非所有菌株 有益，有些会引发炎症。更好地了解这些机制及其意义 对人皮肤免疫防御，在AIM 1中，我们将调查AIP信号是否可以防止皮肤损害 S.金黄色葡萄酒。为了实现这一目标，我们将确定所选皮肤缺点的培养基中的AIP结构 菌株，并在体外和深层组织感染的皮肤模型中测试其活性 浅表定植会驱动皮肤炎症。我们还将比较Cons和S.金黄色葡萄球菌多菌粒 使用外植体和动物模型在皮肤上的相互作用，并评估Cons Agr功能对 抗菌肽的产生和金黄色葡萄球菌混合感染。在AIM 2中，我们提出了失调的 AGR调节的因素是影响皮肤疾病的主要机制。我们的初步研究表明 表皮链球菌ECPA蛋白酶的高表达会促进表皮损伤和随后的炎症。 我们将研究表皮链球菌ECPA蛋白酶的表达和切割的宿主靶标，我们将 比较WT和突变菌株，以定义对皮肤屏障破坏和炎​​症的影响。我们也会 研究使用AIP抑制表皮链球菌ECPA产生的保护性CON物种。定义有害 机制将使人们更好地理解有利于有益和有害缺点生存的因素。目标 3，我们将确定如何使用AGR调节的因子在皮肤上生存。基于我们的初步研究 使用表皮链球菌，我们假设使用Agr Quorum-Sensing系统会菌株菌株使皮肤定居。 我们将评估各种AGR调节的基因座对皮肤生存的影响并评估功能的要求 鉴定出皮肤屏障进入的基因座。我们还将使用RNASEQ确定CONS AGR调节子并进行调查 确定的目标。总的来说，提议的工作的发现将阐明 皮肤微生物组以促进健康并建立稳态。