Adaptation of Staphylococcus aureus to Mn and Zn starvation imposed by the host

金黄色葡萄球菌对宿主造成的锰和锌饥饿的适应

• 批准号: 8814169
• 负责人: Thomas Everett Kehl-Fie
• 金额: $ 10.51万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-01 至 2016-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8814169
• 关键词: Abscess; Affinity; Amino Acids; Antibiotic Resistance; Bacteria; Bacterial Infections; Binding; Biology; C57BL/6 Mouse; Carbon; Collaborations; Communities; Counseling; Development; Disease; Environment; Enzymes; Faculty; Foundations; Future; Glycolysis; Goals; Graduate Degree; Growth; Host Defense; Human body; Immunity; Individual; Infection; Institution; Invaded; Investigation; Ions; Kinetics; Laboratories; Leukocyte L1 Antigen Complex; Manganese; Mediating; Medical; Metals; Methicillin Resistance; Microbiology; Modeling; Molecular; Morbidity - disease rate; Mus; Nosocomial Infections; Nutrient; Nutritional; Oxidative Stress; Pathogenesis; Pathway interactions; Pattern; Positioning Attribute; Postdoctoral Fellow; Process; Proteins; Regulation; Regulon; Research; Research Personnel; Resistance; Role; Running; S100A8 gene; S100A9 gene; Senior Scientist; Site; Source; Staphylococcal Infections; Staphylococcus aureus; Starvation; Stress; Superoxide Dismutase; Superoxides; System; Systemic disease; Technology; Testing; Time; Universities; Variant; Vertebrates; Virulence; Virulent; Washington; Work; Zinc; base; burden of illness; career; career development; combat; follow-up; insight; killings; microbial; mortality; mutant; neutrophil; novel therapeutics; pathogen; post-doctoral training; preference; prevent; programs; response; skills; soft drink; stressor; sugar; transcriptome sequencing; zinc-binding protein

DESCRIPTION (provided by applicant): Bacterial infections are of substantial global concern due to increasing antibiotic resistance. Staphylococcus aureus is a pathogen of alarm because of the ability of the bacterium to infect nearly every site in the human body. This adaptability combined with increasing antibiotic resistance results in the high levels of morbidity and mortality associated with staphylococcal infections. A powerful strategy utilized by vertebrates to combat bacterial pathogens is the sequestration of essential nutrients, a process known as nutritional immunity. Recent work found that during invasive staphylococcal disease mature abscesses are virtually devoid of manganese (Mn) and zinc (Zn). Further work revealed that the sequestration of Mn during staphylococcal infection is dependent on the neutrophil protein calprotectin (CP), a heterodimer of S100A8 and S100A9. CP is capable of binding one Mn ion and two Zn ions with nanomolar affinity, suggesting a role not only in Mn withholding but also in Zn sequestration. In a murine model of infection, CP-deficient mice have increased staphylococcal burdens, indicating that S. aureus is Mn starved during infection. This idea is further supported by the observation that during infection Mn-dependent bacterial processes are inhibited. In total, these results suggest that vertebrates cause S. aureus to become Mn and Zn starved during infection and that this starvation is critical to host defense. Even though vertebrates create an environment virtually devoid of Mn and Zn, S. aureus remains capable of causing significant and devastating disease. These observations led to the hypothesis that S. aureus must somehow adapt to the Mn and Zn limitation imposed by the host. S. aureus is known to encode dedicated Mn and Zn transporters that may help this pathogen resist the effects of vertebrate metal sequestration. However, the increased staphylococcal virulence in CP-deficient mice suggests that expression of Mn transporters, and presumably Zn transporters, by S. aureus is not sufficient to prevent metal starvation. Although it is known that vertebrates sequester Mn and Zn, the kinetics of this process have not been elucidated, and the extent of metal starvation imposed on S. aureus remain unknown. Furthermore, how S. aureus resists and adapts to Mn and Zn starvation imposed by CP remains unclear. Current projects are focused on elucidating the timing of Mn and Zn sequestration, the bacterial processes that are disrupted by this host defense, and the contribution of dedicated Mn and Zn import systems to resisting CP. Once a faculty position has been obtained, investigations will focus on determining how S. aureus adapts to Mn and Zn starvation. The work proposed in this application will follow up on the observations that the ArlRS two-component regulatory system and the two Mn-dependent superoxide dismutases expressed by S. aureus promote resistance to host imposed Mn and Zn limitation. The Specific Aims of this proposal are as follows: Aim I. Evaluate the role of ArlRS regulation and alterations in carbon source preference to facilitating S. aureus adaptation to host-imposed Mn and Zn limitation. Aim II. Determine the individual roles of S. aureus superoxide dismutases in resisting host-imposed metal starvation. In addition to providing substantial insight into the mechanisms that S. aureus uses to evade an important host defense, this proposal will facilitate the development of my independent research career. My long-term goal is to understand how the interactions between host and pathogen influence disease development. In pursuit of this goal, I obtained my graduate degree from Washington University in St. Louis with an emphasis in Molecular Microbiology and Microbial Pathogenesis followed by postdoctoral training in staphylococcal pathogenesis and metals biology with Dr. Eric Skaar at Vanderbilt University. My immediate goal is to obtain a faculty position and establish a highly productive independent research program. The commitment of Vanderbilt University to postdoctoral training, which includes offering seminars on how to run a successful independent laboratory, has substantially enhanced my ability to achieve this goal. To promote a successful transition from postdoctoral fellow to independent investigator, I will seek out advice and counsel from senior scientists at my future institution and an established network of informal advisors. I will also actively pursue opportunities to develop skills that will facilitate running a successful independent laboratory, and cultivate new collaborations. In combination, the proposed investigations and career development activities will provide an excellent foundation for the development of an independent research program.

描述（由申请人提供）：由于抗生素耐药性的增加，细菌感染具有实质性的全球关注。金黄色葡萄球菌是一种警报的病原体，因为细菌几乎感染了人体中每个部位的能力。这种适应能力与抗生素耐药性的增加相结合导致与葡萄球菌感染相关的高水平发病率和死亡率。脊椎动物使用的强大策略 战斗细菌病原体是必需营养物质的隔离，这是一种称为营养免疫的过程。最近的工作发现，在侵入性葡萄球菌疾病期间，成熟的脓肿实际上没有锰（MN）和锌（Zn）。进一步的工作表明，葡萄球菌感染期间MN的固相依赖于中性粒细胞蛋白钙粘蛋白（CP），S100A8和S100A9的异二聚体。 CP能够结合一个具有纳摩尔亲和力的两个Mn离子和两个Zn离子，这不仅表明在MN预扣中，而且在Zn固相中也起作用。在鼠类感染模型中，CP缺陷小鼠的葡萄球菌负担增加，表明金黄色葡萄球菌在感染过程中饿了。观察到在感染中抑制Mn依赖性细菌过程的观察结果进一步支持。总的来说，这些结果表明，脊椎动物会导致金黄色葡萄球菌在感染期间饿死，而这种饥饿对于宿主防御至关重要。即使脊椎动物几乎没有Mn和Zn创造了一个环境，金黄色葡萄球菌仍然能够引起重大毁灭性的疾病。这些观察结果导致了以下假设：金黄色葡萄球菌必须以某种方式适应宿主施加的MN和Zn限制。已知金黄色葡萄球菌可以编码专用的MN和Zn转运蛋白，这些转运蛋白可能有助于该病原体抵抗脊椎动物金属隔离的作用。然而，在CP缺陷型小鼠中增加的葡萄球菌毒力表明，金黄色葡萄球菌的表达和大概是Zn转运蛋白的表达不足以防止金属饥饿。虽然知道 脊椎动物隔离Mn和Zn，该过程的动力学尚未阐明，对金黄色葡萄球菌施加的金属饥饿程度仍然未知。此外，金黄色葡萄球菌如何抵抗并适应CP施加的MN和Zn饥饿。当前项目的重点是阐明MN和Zn固存的时间，该宿主防御的破坏的细菌过程以及专用的MN和Zn进口系统对抵抗CP的贡献。一旦获得了教师职位，调查将集中于确定金黄色葡萄球菌如何适应Mn和Zn饥饿。本应用中提出的工作将跟进以下观察结果：ARLR两组分组的调节系统和金黄色葡萄球菌表达的两个MN依赖性的超氧化物歧化酶促进了对宿主施加的Mn和Zn限制的抗性。该提案的具体目的如下：AIM I.评估ARLRS调节的作用以及碳源偏好在促进金黄色链链球菌适应宿主对寄主MN和Zn限制中的作用。目标II。确定金黄色葡萄球菌超氧化物歧化酶在抵抗宿主施加的金属饥饿中的单个作用。除了对S.金黄色葡萄球菌用来逃避重要的宿主防御的机制外，该提案还将促进我独立的研究职业的发展。我的长期目标是了解宿主与病原体之间的相互作用如何影响疾病的发展。为了实现这一目标，我从圣路易斯的华盛顿大学获得了研究生学位，重点是分子微生物学和微生物发病机理，然后在葡萄球菌发病机理中进行了博士后培训，并与范德比尔特大学的Eric Skaar博士一起在葡萄球菌发病机理中进行了培训。我的直接目标是获得教师职位并建立高产的独立研究计划。范德比尔特大学致力于博士后培训的承诺，其中包括提供有关如何运营独立实验室的研讨会，这显着增强了我实现这一目标的能力。为了促进从博士后研究员到独立调查员的成功过渡，我将向我未来机构的高级科学家和既定的非正式顾问网络寻求建议和建议。我还将积极寻求机会发展有助于的技能 经营成功的独立实验室，并培养新的合作。结合起来，拟议的调查和职业发展活动将为开发独立研究计划提供良好的基础。