Overcoming nutritional immunity: Staphylococcal adaptation to host-imposed manganese and zinc starvation

项目概要/摘要： 细菌感染是人类健康的严重问题，因为细菌感染的持续出现和 抗生素耐药性的传播。疾病控制中心和世界卫生组织的报告 抗生素时代即将结束他们还呼吁开发新的 用于治疗细菌病原体如金黄色葡萄球菌的治疗策略。强大的战略 宿主用来对抗入侵病原体的是限制必需营养素，如锰 (Mn)和锌（Zn）。尽管在感染期间经历了Mn和Zn饥饿，S。金黄色葡萄球菌和其他成功的 病原体仍然能够引起疾病。阐明细菌如何适应这种宿主防御， 有可能确定治疗干预的新靶点，破坏这些靶点将提高 宿主的免疫反应最近的研究表明，一个关键的组成部分，营养扣留 在免疫应答中，最常见的是Mn和Zn结合的免疫效应蛋白钙卫蛋白（CP）。这一发现使得创造 基于CP的新型试剂，可用于施加高度特异性和生物相关的金属 文化中的饥饿利用这些试剂揭示了细菌双组分信号转导 系统ArlRS是葡萄球菌对宿主施加的金属饥饿反应的关键调节剂。 令人惊讶的是，虽然已知ArlRS有助于葡萄球菌的毒力，但激活葡萄球菌的信号可能与ArlRS有关。 系统和系统的直接与间接目标是未知的。进一步研究表明，Mn 锌螯合防止S.金黄色葡萄球菌利用糖，而不是氨基酸作为能源。这 观察表明，锰和锌饥饿破坏糖酵解在S。金黄色。其他物种的最新研究 表明糖酵解依赖于这些金属。他们还透露， puericum Mn依赖性超氧化物歧化酶，这是唯一的S.金黄色葡萄球菌，促进抵抗宿主- 施加营养金属饥饿。总的来说，这些结果导致的假设，S。aureus深刻地改变了 它如何产生能量并表达替代酶以适应宿主施加的Mn和Zn 饥饿本文的目的是对这一假说进行评价并阐明S.金黄色葡萄球菌适应锰 和Zn饥饿。艾姆岛阐明ArlRS监管网络的直接与间接目标， 调节系统活动的环境信号。Aim II.确定Mn和Zn的影响 饥饿对葡萄球菌中枢代谢和碳源偏好影响Aim III.说明金属 可用性影响SodA和SodM对葡萄球菌疾病的贡献。为了实现这些目标 一种跨学科的方法，利用微生物学和生物化学的技术，以及 将使用先进的元素定量和全细胞顺磁光谱。

Project Summary/Abstract: Bacterial infections are of serious concern to human health because of the continued emergence and spread of antibiotic resistance. Reports by both the Centers for Disease Control and World Health Organization have stated that the end of the antibiotic era is upon us. They also called for the development of new therapeutic strategies for treating bacterial pathogens, such as Staphylococcus aureus. A powerful strategy utilized by the host to combat invading pathogens is the restriction of essential nutrients, such as manganese (Mn) and zinc (Zn). Despite experiencing Mn and Zn starvation during infection, S. aureus and other successful pathogens remain capable of causing disease. Elucidating how bacteria adapt to this host defense has the potential to identify new targets for therapeutic intervention, the disruption of which will enhance the efficacy of the host immune response. Recent work revealed that a critical component of the nutrient withholding response is the Mn- and Zn-binding immune effector protein calprotectin (CP). This finding allowed the creation of novel reagents based on CP that can be used to impose highly specific and biologically relevant metal starvation in culture. Utilizing these reagents revealed that the bacterial two-component signal transduction system ArlRS is a critical regulator of the staphylococcal response to host-imposed metal starvation. Surprisingly, while ArlRS is known to contribute to staphylococcal virulence, the signal that activates the system and the direct vs. indirect targets of the system are unknown. Further investigations suggest that Mn and Zn sequestration prevents S. aureus from utilizing sugars, but not amino acids, as an energy source. This observation suggests that Mn and Zn starvation disrupts glycolysis in S. aureus. Recent work in other species has shown that glycolysis can be dependent on these metals. They also revealed that the expression of two putatively Mn-dependent superoxide dismutases, which is unique to S. aureus, promotes resistance to host- imposed nutrient metal starvation. In total, these results lead to the hypothesis that S. aureus profoundly alters how it generates energy and expresses alternative enzymes in order to adapt to host-imposed Mn and Zn starvation. The Aims of this proposal will evaluate this hypothesis and elucidate how S. aureus adapts to Mn and Zn starvation. Aim I. Elucidate the direct vs. indirect targets of the ArlRS regulatory network and the environmental signals that modulate activity of the system. Aim II. Determine the impact of Mn and Zn starvation on staphylococcal central metabolism and carbon source preference. Aim III. Elucidate how metal availability impacts the contributions of SodA and SodM to staphylococcal disease. To accomplish these aims an interdisciplinary approach utilizing techniques taken from microbiology and biochemistry, as well as advanced elemental quantification and whole cell paramagnetic spectroscopy, will be utilized.