Virulence of Staphylococcus aureus Corneal Infections

摘要 细菌性角膜炎（角膜感染）是一种威胁视力的疾病， 失明重要的人类病原体金黄色葡萄球菌（Staphylococcus aureus）是角膜炎的主要原因， 侵袭性感染通常导致无法修复的眼组织损伤。虽然人们对 了解S.金黄色葡萄球菌在非眼部感染部位，如败血症，心内膜炎或 令人惊讶的是，对于控制S.金黄色 角膜炎。缺乏这方面的知识，就不可能理解S. 金黄色角膜炎或合理设计治疗方法来治疗这种致盲性疾病。因此，中心目标 该建议的目的是识别和表征S。调节角膜炎的金黄色葡萄球菌遗传决定因素。 鉴于眼表和角膜相对于泪膜组成的独特环境， 从眨眼产生的力量，和相对免疫特权，我们假设将有一组独特的 导致角膜炎的毒力因子我们的实验室已经开发出了创新的工具， 时间，前瞻性地识别和验证全面的S。金黄色葡萄球菌毒力因子， 在BK发病机制中发挥作用。我们的发现管道利用最先进的基因组学和生物信息学 包括全基因组测序，Tn-seq和RNA-seq，以产生高优先级的线索， 作用研究，以及在我们的小鼠角膜炎模型中的生物学意义的评价。我们有 成功地使用这种方法来鉴定和验证肠毒素，分泌的细菌蛋白质， 它们的细胞毒性和调节宿主免疫应答的能力在介导角膜炎中是重要的。因此，在本发明中， 该提案将建立在这些令人兴奋的初步数据的基础上，以开发角膜炎关键驱动因素的扩展列表。 最终，这项工作将直接推进我们对S的理解。金黄色角膜炎的发病机制， 可能是支持这种使人衰弱的疾病的治疗干预策略的基础。

ABSTRACT Bacterial keratitis (corneal infection) is a vision threatening disease and contributes significantly to world blindness. The important human pathogen, Staphylococcus aureus, is a predominant cause of keratitis, causing aggressive infections that often lead to irreparable ocular tissue damage. While much attention has been given to understanding the pathogenesis of S. aureus in non-ocular sites of infection such as sepsis, endocarditis or osteomyelitis, surprisingly, relatively little is yet known about the bacterial virulence factors that govern S. aureus keratitis. In the absence of this knowledge, it is impossible to understand the fundamental pathogenesis of S. aureus keratitis or rationally design therapeutics to treat this blinding disease. Accordingly, the central goal of this proposal is to identify and characterize S. aureus genetic determinants that modulate keratitis. Given the unique environment of the ocular surface and cornea with respect to tear film composition, sheer forces generated from blinking, and relative immune privilege, we hypothesize that there will be a unique set of virulence factors that drive keratitis. Our laboratory has developed innovative tools that will allow, for the first time, the ability to prospectively identify and validate the comprehensive set of S. aureus virulence factors that play a role in BK pathogenesis. Our discovery pipeline leverages state of the art genomics and bioinformatics including whole genome sequencing, Tn-seq and RNA-seq to generate high priority leads for mechanism of action studies, as well as the evaluation of biologic significance in our murine model of keratitis. We have successfully used this approach to identify and validate enterotoxins, secreted bacterial proteins well known for their cytotoxicity and ability to modulate the host immune response, as important in mediating keratitis. Thus, this proposal will build on this exciting preliminary data to develop an expanded list of the key drivers of keratitis. Ultimately this work will directly advance our understanding of S. aureus keratitis pathogenesis and as such, may be foundational in supporting strategies for the therapeutic intervention of this debilitating disease.