Identifying mucin O-glycans in the regulation of Staphylococcus aureus pathogenesis

项目摘要/摘要 该项目的目标是利用粘蛋白O-葡聚糖作为有效的天然化合物来抑制生物膜 条件致病菌的形成、聚集等重要毒力基因和致病途径 金黄色葡萄球菌(S.aureus)金黄色葡萄球菌会引起许多令人衰弱的感染，并在 作为坚固的生物膜持续存在。生物膜很难根除，因为它们能够逃避宿主的免疫， 对抗菌素有耐受性，并增加了抗药性的出现。抑制的治疗策略 预防金黄色葡萄球菌生物被膜的形成是当务之急。粘液是一种关键的防御机制 在许多器官系统的上皮衬里上，它可以抑制许多重要的毒力反应 金黄色葡萄球菌通过显示在粘蛋白聚合物上的多聚糖。因此，粘液具有很强的治疗作用。 开发新的方法来对抗这种有问题的病原体。粘蛋白多肽骨架被移植到 具有数百种独特的糖链结构。它们特殊的毒力潜力--粘蛋白的减弱-- 相关的多糖已经被认识到有一段时间了，但因为它们的个体生物活性 难以分析的是，它们的潜力几乎没有被挖掘出来。我们将通过利用我们的集体来缩小这一差距 在微生物学、粘蛋白生物学、葡聚糖化学和体内感染模型方面的专业知识，以识别单个和 抑制金黄色葡萄球菌生物膜形成和聚集的一小群粘蛋白多聚糖。我们的试点数据很强 支持这项研究的前提和可行性：粘蛋白多糖抑制与金黄色葡萄球菌有关的毒力基因 人中性粒细胞的生物膜形成、聚集/聚集和毒素介导的裂解，所有这些都是 在感染中很重要。这些发现支持粘蛋白多糖在宿主保护中的核心作用，并提供了 推动确定与抗毒力作用有关的多糖结构。我们的目标是提供更多- 需要毒性减弱的分子来管理这种有问题的病原体，这些病原体来自丰富的和未开发的 作为宿主防御基础的生物糖链的天然文库。我们将结合功能多糖分析， 微生物学和体内感染研究，以确定抑制金黄色葡萄球菌毒力的调节粘蛋白O-聚糖。 在目标1中，我们将从粘蛋白中获取生物活性多糖，以生成用于功能分析的注释库 并鉴定那些能抑制金黄色葡萄球菌生物膜形成和聚集的O-糖链。在目标2中，我们将 研究粘蛋白O-葡聚糖对已建立的人中性粒细胞和体内的抗毒力作用 感染模型。这个项目意义重大，因为它将使我们能够阐明和利用无数 多糖和粘蛋白对金黄色葡萄球菌及其宿主的生物学作用。这项提议还建立了一个坚定的试验性 可能导致预防和治疗金黄色葡萄球菌感染的关键变化的基础工作。此外， 许多广为人知的抗生素含有作为其核心结构一部分的葡聚糖。因此，成功的身份识别 在体内验证能减弱金黄色葡萄球菌毒力的O-葡聚糖有可能创造出令人兴奋的新的 以葡聚糖为基础的或模拟疗法，加强甚至取代抗生素的使用。

PROJECT SUMMARY/ABSTRACT The goal of this project is to leverage mucin O-glycans as potent natural compounds that suppress biofilm formation, aggregation, and other important virulence genes and pathways in the opportunistic pathogen Staphylococcus aureus (S. aureus). S. aureus causes numerous debilitating infections and is successful at persisting as robust biofilms. Biofilms are difficult to eradicate because they are able to evade host immunity, are tolerant to antimicrobials, and increase antibiotic-resistance emergence. Therapeutic strategies to suppress and prevent the S. aureus biofilm formation are urgently needed. Mucus functions as a key defense mechanism on epithelial linings of numerous organ systems and it can suppress numerous important virulence responses of S. aureus via the glycans displayed on mucin polymers. Therefore, mucus has strong potential for the development of new approaches to combat this problematic pathogen. Mucin polypeptide backbones are grafted with several hundred unique glycan structures. Their exceptional potential for virulence-attenuation of mucin- associated glycans has been recognized for some time, but because their individual bioactivities have been intractable to analysis, their potential has barely been tapped. We will close this gap by harnessing our collective expertise in microbiology, mucin biology, glycan chemistry, and in vivo infection models to identify single and small groups of mucin glycans that inhibit S. aureus biofilm formation and aggregation. Our pilot data strongly support the premise and feasibility of this study: mucin glycans suppress virulence genes involved with S. aureus biofilm formation, clumping/aggregation, and toxin-mediated lysis of human neutrophils, all of which are important in infection. These findings support a central role for mucin glycans in host protection and provide the impetus to identify glycan structures responsible for the anti-virulence effects. Our goal is to provide much- needed virulence-attenuating molecules to manage this problematic pathogen, drawn from the rich and untapped natural library of biological glycans underlying host defense. We will combine functional glycan analysis, microbiology, and in vivo infection studies to identify regulatory mucin O-glycans that impede S. aureus virulence. In Aim 1, we will harvest bioactive glycans from mucins to generate annotated libraries for functional analysis and identify those O-glycans that attenuate S. aureus biofilm formation and aggregation. In Aim 2, we will investigate the anti-virulence effects of mucin O-glycans in well-established human neutrophil- and in vivo infection models. This project is significant because it will empower us to elucidate and harness the myriad biological functions of glycans and mucins on S. aureus and its host. This proposal also sets a firm experimental groundwork that could lead to pivotal changes in the prevention and treatment of S. aureus infection. Moreover, many well-known antibiotics contain glycans as part of their core structure. Therefore, successful identification and in vivo validation of O-glycans that attenuate S. aureus virulence has the potential to create exciting new glycan-based or -mimetic therapeutics that enhance, or even replace, the use of antibiotics.