Staphylococcus aureus induced itch and neuro-immune signaling in skin infections

金黄色葡萄球菌在皮肤感染中引起瘙痒和神经免疫信号传导

基本信息

批准号：
10707178
负责人：
Isaac Ming-Cheng Chiu
金额：
$ 73.54万
依托单位：
HARVARD MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-19 至 2027-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10707178
关键词：
Ablation Afferent Neurons Affinity Atopic Dermatitis Automobile Driving Behavior Binding Biochemical Biological Biological Assay Calcium Cells Cheek structure Complement Data Detection Disease Enzyme-Linked Immunosorbent Assay Esthesia Family G-Protein-Coupled Receptors Genetic Goals Human Image Immune Immune response Immunologics Impetigo Infection Infectious Skin Diseases Inflammation Inflammation Mediators Lesion Link Measures Mediating Mediator Microbe Modeling Molecular Molecular Target Mus Nerve Nervous System Neurobiology Neuroimmune Neurons PAR-1 Receptor Pain Pathogenesis Pathology Patients Peptide Hydrolases Play Production Proteinase-Activated Receptors Proteomics Pruritus Recombinants Role Serine Protease Signal Transduction Site Skin Small Interfering RNA Spinal Ganglia Staphylococcus aureus Staphylococcus aureus infection Symptoms TRPV1 gene Therapeutic Touch sensation Virulence Factors Work antagonist chronic itch cytokine extracellular genetic approach glutamyl endopeptidase host-microbe interactions immunoregulation intradermal injection knock-down luminescence microbial mutant neural neurobehavioral neurotransmission neutrophil novel pain behavior pathogenic bacteria pharmacologic proteinase In receptor response skills skin barrier skin damage skin disorder skin lesion subcutaneous

项目摘要

PROJECT SUMMARY Itch is an unpleasant sensation that evokes a desire to scratch. While itch accompanies many skin infections, a causative role for microbes in itch has not been previously investigated. Itch-induced scratching can contribute to significant skin damage and bacterial pathogenesis. Here, we investigate the role of the human bacterial pathogen Staphylococcus aureus and its secreted proteases in driving itch and inflammation. S. aureus colonizes 90% of skin lesions caused by Atopic Dermatitis, a disease characterized by chronic itch. S. aureus also causes impetigo, a contagious skin disease characterized by itchy lesions. We hypothesize that S. aureus secretes proteases that can directly act on host sensory neurons to drive itch, scratch-induced skin damage, and neuroimmune crosstalk. Our preliminary data shows that S. aureus epicutaneous infection of mice induces robust itch behaviors (alloknesis, spontaneous itch) and resulting skin pathology. Using isogenic mutant strains, we find that secreted S. aureus proteases, and in particular the serine protease V8 (SspA) is required for itch production during infection. In Specific Aim 1, we will determine the role of S. aureus V8 protease in driving itch, neuronal activation, and skin inflammation. We will utilize isogenic S. aureus mutant and complemented strains for V8, as well as recombinant V8 to elucidate the necessity and sufficiency of this protease in inducing itch, scratch induced damage, and inflammation caused by S. aureus. Itch is mediated by dorsal root ganglia (DRG) sensory neurons. DRG neuron calcium imaging will be performed to investigate specific neuronal responses to V8 protease. Cheek intradermal injections and neurobehavioral analysis will be performed to distinguish itch vs. pain behaviors in mice. In Specific Aim 2, we will determine whether neurons and host cells detect S. aureus V8 protease through specific protease-activated receptors (PARs). Preliminary data indicates that PAR1 may be an important host receptor that is activated by V8. We will utilize biochemical and luminescence-based approaches to determine the V8 cleavage site on PAR1. We will treat mice with pharmacological antagonists against PAR1 and utilize PAR1-/- mice to determine effects on V8-protease and S. aureus induced itch. In Specific Aim 3, we will utilize genetic approaches to ablate specific skin-innervating neurons (Nav1.8+, Mrgprd+, and Trpv1+) to assay their roles in S. aureus induced inflammation. We hypothesize that neurons will drive both itch/scratch-induced damage, and the release of neural mediators that directly signal to immune cells. We will use targeted approaches and proteomics to assess neuronal release of proinflammatory mediators. Our work could elucidate novel molecular crosstalk between S. aureus, host neurons and immune cells in itch. The three aims of this study leverage the complementary skills of Dr. Chiu and Dr. Horswill, combining neurobiological, immunological, and microbiological approaches to investigate the mechanisms of itch and neuroimmune signaling in S. aureus infection. Given the importance of itch in skin diseases, elucidating a microbial role in inducing this sensation could transform our understanding of host-microbe interactions at the skin barrier.

项目摘要瘙痒是一种令人不愉快的感觉，唤起了刮擦的欲望。瘙痒伴随着许多皮肤感染，但先前尚未研究微生物在瘙痒中的致病作用。瘙痒引起的划痕会贡献严重的皮肤损伤和细菌发病机理。在这里，我们研究了人类细菌的作用金黄色葡萄球菌及其分泌的蛋白酶在驱动瘙痒和炎症时。 S.金黄色葡萄酒在特应性皮炎引起的90％的皮肤病变中殖民，这种疾病是慢性瘙痒。 S.金黄色葡萄酒还会导致Impetigo，这是一种传染性的皮肤疾病，其特征是发痒的病变。我们假设金黄色葡萄球菌分泌可以直接作用于宿主感觉神经元的蛋白酶，以驱动瘙痒，刮擦引起的皮肤损伤和神经免疫串扰。我们的初步数据表明，小鼠的金黄色葡萄球菌的表皮感染会诱导强大的瘙痒行为（Alloknesis，自发瘙痒）和由此产生的皮肤病理学。使用等源性突变菌株，我们发现瘙痒需要分泌的金黄色葡萄球菌蛋白酶，尤其是丝氨酸蛋白酶V8（SSPA）感染期间的生产。在特定目标1中，我们将确定金黄色葡萄球菌V8蛋白酶在驱动瘙痒中的作用，神经元激活和皮肤炎症。我们将利用等源性金黄色葡萄球菌突变体和补充菌株对于V8，以及重组V8，以阐明该蛋白酶在诱导性基的必要性和充分性，刮擦引起的损害和由金黄色葡萄球菌引起的炎症。瘙痒是由背根神经节（DRG）介导的感觉神经元。将执行DRG神经元钙成像，以研究对特定的神经元反应 V8蛋白酶。将进行脸颊内注射和神经行为分析，以区分瘙痒与。小鼠的疼痛行为。在特定目标2中，我们将确定神经元和宿主细胞是否检测到金黄色葡萄球菌 V8蛋白酶通过特定的蛋白酶激活受体（PAR）。初步数据表明PAR1可能是由V8激活的重要宿主受体。我们将利用基于生化和发光的在PAR1上确定V8裂解位点的方法。我们将用药理学拮抗剂治疗小鼠针对PAR1并利用PAR1 - / - 小鼠来确定对V8-蛋白酶和金黄色葡萄球菌诱导的性感的影响。在特定的目标3，我们将利用遗传方法消除特定皮肤的神经元（NAV1.8+，MRGPRD+，和TRPV1+）分析其在金黄色葡萄球菌诱导的炎症中的作用。我们假设神经元会驱动两者瘙痒/刮擦诱导的损伤，以及直接发出免疫细胞的神经介质的释放。我们将使用靶向方法和蛋白质组学来评估促炎介质的神经元释放。我们的工作可以阐明金黄色葡萄球菌，宿主神经元和瘙痒中的免疫细胞之间的新型分子串扰。三个这项研究的目的利用了Chiu博士和Horswill博士的互补技能，结合了神经生物学，免疫学和微生物学方法研究瘙痒和神经免疫的机制金黄色葡萄球菌感染中的信号传导。鉴于瘙痒在皮肤疾病中的重要性，阐明了微生物在引起这种感觉可以改变我们对皮肤屏障上宿主微叶相互作用的理解。