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

项目总结/摘要 该项目的目标是利用粘蛋白O-聚糖作为有效的天然化合物，抑制生物膜 条件致病菌的形成、聚集等重要毒力基因和途径 金黄色葡萄球菌(S. aureus)具有良好的抗菌活性。S.金黄色葡萄球菌可导致多种衰弱性感染， 作为坚固的生物膜持续存在。生物膜难以根除，因为它们能够逃避宿主免疫， 对抗菌剂具有耐受性，并增加了抗生素耐药性的出现。抑制的治疗策略 并防止S.金黄色葡萄球菌生物膜形成是迫切需要的。粘液是一种重要的防御机制 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 S.通过粘蛋白聚合物上展示的聚糖。因此，粘液具有很强的 开发新的方法来对抗这种问题病原体。粘蛋白多肽骨架嫁接 有几百个独特的聚糖结构。它们在减毒作用方面的特殊潜力 相关的聚糖已经被认识了一段时间，但由于它们各自的生物活性 它们的潜力难以分析，几乎没有得到开发。我们将利用我们的集体力量来缩小这一差距 在微生物学、粘蛋白生物学、聚糖化学和体内感染模型方面的专业知识，可识别单个和 抑制链球菌的一小群粘蛋白聚糖金黄色葡萄球菌生物膜形成和聚集。我们的试点数据显示 支持了本研究的前提和可行性：粘蛋白聚糖抑制与S.金黄色 生物膜形成、结块/聚集和毒素介导的人嗜中性白细胞的溶解，所有这些都 在感染中很重要。这些发现支持了粘蛋白聚糖在宿主保护中的核心作用，并提供了 推动鉴定负责抗毒力作用的聚糖结构。我们的目标是提供- 我需要减毒分子来控制这个有问题的病原体，从丰富的和未开发的 作为宿主防御基础的生物聚糖的天然文库。我们将联合收割机功能性聚糖分析， 微生物学和体内感染研究，以鉴定阻碍S.金黄色葡萄球菌毒力。 在目标1中，我们将从粘蛋白中收获生物活性聚糖，以生成用于功能分析的注释文库 并鉴定那些使S.金黄色葡萄球菌生物膜形成和聚集。在目标2中，我们将 研究粘蛋白O-聚糖在成熟的人中性粒细胞和体内的抗毒性作用 感染模型。这个项目意义重大，因为它将使我们能够阐明和驾驭 多糖和粘蛋白对S.金黄色葡萄球菌及其宿主。这一建议也树立了坚定的实验性 这可能会导致在预防和治疗S.金黄色葡萄球菌感染。此外，委员会认为， 许多公知的抗生素含有聚糖作为其核心结构的一部分。因此，成功识别 和体内验证减弱S.金黄色葡萄球菌的毒力有可能创造令人兴奋的新 基于聚糖的或模拟聚糖的治疗剂，其增强或甚至替代抗生素的使用。

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.