Prevention of intracellular infection in diabetic wounds by commensal Staphylococcus epidermidis

共生表皮葡萄球菌预防糖尿病伤口细胞内感染

基本信息

批准号：
10679628
负责人：
Irena Pastar
金额：
$ 60.82万
依托单位：
UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-05-03 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10679628
关键词：
Acceleration Acute Adult Affect Agonist Amputation Animal Model Anti-Bacterial Agents Bacteria Cells Chronic Clinical Complications of Diabetes Mellitus Cutaneous Data Data Set Development Diabetic Foot Diabetic Foot Ulcer Diabetic mouse Down-Regulation Epithelium Evaluation Exposure to FOXM1 gene Functional disorder Gene Expression Profile Genetic Transcription Genus staphylococcus Goals Healthcare Systems Human Immune Impaired wound healing Impairment Infection Infection prevention Infectious Skin Diseases Inflammasome Inflammation Inflammatory Response Innate Immune Response Intervention Knowledge Leg Lower Extremity Macrophage Mediating Modeling Molecular Morbidity - disease rate Mus Outcome Pathogenesis Pathogenicity Pathway interactions Patients Phagocytes Population Prevention Process Proteins Quality of life Recurrence Risk Role Sampling Skin Small Interfering RNA Staphylococcus aureus Staphylococcus aureus infection Staphylococcus epidermidis TLR1 gene TLR2 gene TLR6 gene Testing Therapeutic Tissue Preservation Tissue Sample Tissues Transcriptional Regulation Ulcer Work Wound Infection Wound models acute wound antimicrobial comparative genomics cost diabetic diabetic patient diabetic ulcer diabetic wound healing effective therapy extracellular fighting healing human model in vivo insight keratinocyte limb amputation methicillin resistant Staphylococcus aureus microbiome microorganism mortality mouse model neutrophil new therapeutic target non-diabetic novel novel therapeutic intervention pathogen perforin 2 prevent response transcriptomics treatment strategy wound wound environment wound healing γδ T cells

项目摘要

Abstract Diabetic foot ulcers (DFUs) and diabetic foot infections (DFI) are one of the most challenging complications of diabetes due to high morbidity and associated mortality and precede the majority of non-traumatic lower limb amputations in the adult population. Diabetic foot microbiome of intact skin, prior to the onset of the ulcer, is characterized by the low level of Staphylococcus epidermidis (SE) and high levels of Staphylococcus aureus (SA). Persistent level of bacteria in ulcer tissue, resulting in prolonged and deregulated inflammation is one of the leading causes of lower leg amputations in patients suffering from DFUs. To gain greater insight into relationship between innate immune responses and wound healing outcomes, we propose to study how commensal microorganism SE prevents intracellular accumulation of SA and accelerates the diabetic wound healing process. The long term goal of this project is to prevent DFI by understanding the mechanism and developing new therapeutic strategies targeting cutaneous intracellular pathogens in patients with DFUs. We have already shown that downregulation of an innate-antimicrobial protein P-2 in keratinocytes and gamma delta (GD) T cells results in accumulation of intracellular MRSA in DFUs, contributing to persistent unresolved inflammation. Furthermore, loss of P-2 in murine models is associated with both, lower antimicrobial activity and accumulation of intracellular MRSA, and impaired epithelialization. Importantly, we have shown that killing of intracellular MRSA is enhanced in skin after exposure to SE. Based on robust preliminary data we postulate that SE colonization modifies diabetic skin and wound environment to prevent intracellular infections by pathogenic SA. Our hypothesis is that intracellular bacteria modify expression and function of P-2 to affect bacterial clearance and inflammatory response, directly impacting healing in DFU. The objective of this project is to determine mechanism by which SE prevents intracellular infections by pathogenic SA in a diabetic mouse and human wounds. We hypothesized that SE colonization modifies wound environment in order to prevent or resolve persistent bacterial wound infections. To test our hypothesis, we will evaluate SE-mediated induction of P-2 in professional and non-professional phagocytes during acute diabetic and non-diabetic wound healing process in vivo, using multiple animal and human models and samples obtained from DFU patients. We will also identify gene expression signatures and pathways in these cells that are differentially regulated in “low intracellular SA non-healing” vs “high intracellular SA healing” DFU (Aim 1). We will characterize SE protective mechanisms against intracellular MRSA in diabetic wound infections (Aim 2). Our findings will provide important new knowledge regarding the role and mechanisms by which commensal SE may prevent persistent diabetic wound infections. Targeting intracellular bacteria niche to accelerate healing in diabetic patients at risk of cutaneous and wound infections has potential to achieve a major clinical impact in promoting healing and reducing amputations.

抽象的糖尿病足溃疡（DFU）和糖尿病足感染（DFI）是最挑战的并发症之一由于高发病率和相关死亡率引起的糖尿病，并在大多数非创伤下肢之前成年人口的截肢。溃疡发作之前，完整皮肤的糖尿病脚微生物组为以低水平的葡萄球菌表皮（SE）和高水平的金黄色葡萄球菌为特征（SA）。溃疡组织中细菌的持续水平，导致炎症长期和失调的炎症是患有DFU的患者截肢截肢的主要原因。为了更深入地了解先天免疫反应与伤口愈合结果之间的关系，我们建议研究如何共生微生物SE可防止SA的细胞内加速度并加速糖尿病伤口康复过程。该项目的长期目标是通过了解机制和开发针对DFU患者皮肤细胞内病原体的新的治疗策略。我们已经表明，在角质形成细胞和伽马中的先天抗抗菌蛋白P-2下调 Delta（GD）T细胞导致细胞内MRSA在DFU中积累，从而导致持续未解决炎。此外，鼠模型中P-2的损失与较低的抗菌活性有关和细胞内MRSA的积累，以及上皮化受损。重要的是，我们已经证明了杀人暴露于SE后，皮肤上的细胞内MRSA的增强。基于强大的初步数据，我们假设 SE定植改变了糖尿病皮肤和伤口环境，以防止细胞内感染致病SA。我们的假设是细胞内细菌改变了P-2的表达和功能以影响细菌清除和炎症反应，直接影响DFU的愈合。这个项目的目的是为了确定SE通过致病小鼠中病原SA阻止细胞内感染的机制人赢了。我们假设SE定植修改了伤口环境，以防止或解决持续的细菌伤口感染。为了检验我们的假设，我们将评估SE介导的诱导急性糖尿病和非糖尿病伤口愈合期间的专业和非专业吞噬细胞中的P-2 使用从DFU患者获得的多个动物和人类模型以及样品进行体内处理。我们将还确定这些细胞中基因表达特征和途径在“低低”中受到不同调控细胞内SA非修改”与“高细胞内SA愈合” DFU（AIM 1）。我们将表征SE保护性糖尿病伤口感染中针对细胞内MRSA的机制（AIM 2）。我们的发现将提供关于Comensal SE可能阻止持续性的角色和机制的重要新知识糖尿病伤口感染。靶向细胞内细菌生态位以加速有风险的糖尿病患者的愈合皮肤和伤口感染有可能在促进愈合和减少截肢。