Defining SaeR/S-dependent Neutrophil-S. aureus Interactions that Determine the Outcome of Infection

定义 SaeR/S 依赖性中性粒细胞-S。

• 批准号: 10408775
• 负责人: Tyler K Nygaard
• 金额: $ 60.9万
• 依托单位: MONTANA STATE UNIVERSITY - BOZEMAN
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-16 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10408775
• 关键词: Address; Antibiotic Resistance; Antibiotics; Apoptosis; Autophagocytosis; Bacterial Genes; Bacterial Infections; Cell Communication; Cell Culture System; Cell Culture Techniques; Cells; Communities; Complement; Cytolysis; Data; Development; Disease; Drug resistance; Effectiveness; Environment; Event; Foundations; Functional disorder; Future; Gene Expression; Genes; Genetic Transcription; High Prevalence; Hospitals; Human; Immune; Immune response; Immunotherapeutic agent; Individual; Infection; Inflammation Mediators; Intelligence; Life; Link; Mediating; Methods; Modeling; Molecular; Morbidity - disease rate; Natural Immunity; Necrotizing fasciitis; Neutrophil Infiltration; Outcome; Outpatients; Pathogenesis; Pathway interactions; Peripheral Blood Mononuclear Cell; Peroxidases; Phagocytosis; Play; Population; Production; Public Health; Publishing; RNA; Reactive Oxygen Species; Regulation; Regulator Genes; Reporting; Research; Resistance development; Risk; Role; Sepsis; Severities; Signal Transduction; Skin; Soft Tissue Infections; Staphylococcus aureus; Staphylococcus aureus infection; System; TNF gene; Testing; Therapeutic; Time; Transcript; Up-Regulation; Vaccines; Virulence; Visit; antimicrobial; base; clinically significant; combat; community setting; design; emerging pathogen; experimental study; extracellular; improved; in vivo; leukotoxin; monocyte; mortality; mouse model; neutrophil; next generation sequencing; novel; novel therapeutics; novel vaccines; pathogen; prevent; response; sensory system; skin abscess; transcriptome; transcriptome sequencing

Staphylococcus aureus (S. aureus) is one of the most frequent causes of bacterial infections in the U.S. and is responsible for diverse types of infections ranging in severity from mild to fatal in both hospital and community settings. In the community, S. aureus typically causes skin-and-soft-tissue infections with an estimated 12 – 13 million outpatient visits per-year (in the U.S.) but can also cause severe manifestations including necrotizing fasciitis and sepsis in individuals with no underlying risk. One of the most clinically significant aspects of S. aureus infections is the high prevalence of drug resistance and the innate ability for S. aureus to develop resistance to antibiotics making it very difficult to develop therapeutics that will have potential for long-term efficacy on S. aureus. The research proposed in this application will broaden our understanding of host- pathogen interactions, providing the foundation for future studies aimed at the intelligent design of novel vaccines and therapies to treat bacterial infection. To that end, this project will study how S. aureus uses the SaeR/S two-component gene regulatory system to evade innate immunity. The SaeR/S system is essential for evasion of neutrophil killing; however, exact mechanisms dependent on SaeR/S resulting in neutrophil dysfunction are not defined. Three specific Aims will test the hypothesis that the SaeR/S-mediated up- regulation of S. aureus virulence genes undermines an effective neutrophil response that would normally clear infection. In Aim One, host pathogen RNA expression via RNA-seq will be used to determine the direct influence of SaeR/S-regulated bacterial genes on human neutrophil gene expression as well as resolve the individual contribution of SaeR/S components on neutrophil and pathogen gene expression simultaneously. In Aim Two, we will determine how SaeR/S-dependent changes in neutrophil human myeloperoxidase (MPO) activity and the production reactive oxygen species (ROS) alters neutrophil apoptosis and neutrophil extracellular trap (NET) formation. In Aim Three, we will utilize a novel ex vivo model of neutrophil priming by stimulated PBMCs to determine the role of initial SaeR/S-mediated immune cell interactions on subsequent neutrophil function. These ex vivo primary human cell studies will be complemented with murine models of infection to thoroughly evaluate these immune responses. Findings from experiments outlined in this proposal will improve our overall understanding of host-pathogen interactions by specifically characterizing novel SaeR/S-mediated mechanisms used by S. aureus to overcome an effective neutrophil response. Collectively this research will address our long-term objective to characterize reciprocal response pathways between host and pathogen that will highlight key factors needed for both the pathogen to cause infection and for the host to resolve disease. Results will provide valuable information for vaccine and immunotherapeutic development.

金黄色葡萄球菌（金黄色葡萄球菌）是美国最常见的细菌感染原因之一，是 负责潜水员类型的感染类型，从医院和社区的轻度到致命的严重程度不等 设置。在社区中，金黄色葡萄球菌通常会引起皮肤和柔软的组织感染，估计有12 - 每年1300万门诊就诊（在美国），但也可能引起严重的表现 没有潜在风险的个体的筋膜炎和败血症。 S. 金黄色葡萄球菌感染是药物抗性的高流行，以及金黄色葡萄球菌的先天能力 对抗生素的耐药性使得很难开发长期的治疗 金黄色葡萄球菌的效率。本应用程序中提出的研究将扩大我们对宿主的理解 - 病原体相互作用，为未来研究的基础提供了针对新颖设计的智能设计 疫苗和治疗细菌感染的疗法。为此，该项目将研究S.金黄色葡萄球菌如何使用 SAER/S两个组分基因调节系统，以逃避先天免疫。 SAER/S系统对于 逃避中性粒细胞杀害；但是，确切的机制取决于SAER，导致中性粒细胞 功能障碍未定义。三个特定目标将检验以下假设：SAER/S介导的上 金黄色葡萄球菌病毒基因的调节破坏了有效的嗜中性粒细胞反应，通常会清除 在AIM中，通过RNA-Seq的宿主病原体RNA表达将用于确定直接 SAER/S调节细菌基因对人中嗜中性粒细胞基因表达的影响以及解决 SAER/S成分对中性粒细胞和病原体基因表达的个人贡献。 目标二，我们将确定中性粒细胞人脊髓过氧化物酶（MPO）的SAER/S依赖性变化如何 活性和生产活性氧（ROS）改变中性粒细胞凋亡和中性粒细胞 细胞外陷阱（净）形成。在AIM三中，我们将利用一种新型的嗜中性粒细胞启动的离体模型 刺激的PBMC确定初始SAER/S介导的免疫细胞相互作用对随后序列的作用 中性粒细胞功能。这些离体原代人细胞研究将通过鼠模型完成 感染以彻底评估这些免疫反应。该提案中概述的实验的发现 将通过专门表征新颖的新颖性来提高我们对宿主病原体相互作用的整体理解 金黄色葡萄球菌使用的SAER/S介导的机制克服了有效的中性粒细胞反应。集体 这项研究将解决我们的长期目标，以表征宿主之间的相互响应途径 病原体将突出病原体引起感染所需的关键因素和宿主 解决疾病。结果将为疫苗和免疫治疗开发提供有价值的信息。