Mammalian metal transporters & Salmonella infection

哺乳动物金属转运蛋白

• 批准号: 7140197
• 负责人: Bobby Joseph Cherayil
• 金额: $ 24.94万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7140197
• 关键词: Salmonella; Salmonella infections; bacteria infection mechanism; cell line; host organism interaction; ion transport; laboratory mouse; macrophage; membrane transport proteins; microorganism growth; phagocytosis; protein localization; protein structure function; vesicle /vacuole; virulence

DESCRIPTION (provided by applicant): Salmonellae cause either acute gastroenteritis or the systemic febrile illness typhoid in humans. Both syndromes are significant public health problems worldwide. The interactions between Salmonella and mammalian cells that result in invasion and intracellular growth of the bacteria depend on both bacterial and host factors. Metal ions such as iron, magnesium and manganese play important roles in these interactions. Mutations in bacterial proteins that are involved in the binding or transport of these metals have major effects on Salmonella virulence. Correspondingly, mutations in the mammalian divalent metal transporter Nrampl result in increased susceptibility to Salmonella infection. Based on these observations, I hypothesized that mammalian metal transporters other than Nramp1 might also influence Salmonella-host cell interactions. In support of this idea, I present preliminary evidence showing that the iron efflux protein ferroportin 1 (FPN1), a member of the solute carrier (SLC) family of transporters that includes Nramp1, significantly inhibits the intracellular growth of Salmonella when expressed in HeLa cells. The experiments in this proposal will extend this line of investigation to: (a) Elucidate the mechanism of the bacteriostatic effect of FPN1, by examining its sub-cellular localization, involvement of its iron transport function in bacteriostasis, and its effects on movement of iron into or out of the phagosome. (b) Clarify the role of FPN1 in the growth of Salmonella inside macrophages, the cell type that is chronically infected by this organism in vivo in systemic disease, using siRNA technology to knock-down expression of the protein, (c) Identify other metal ion transporters of the SLC family that might influence the intracellular growth of Salmonella by using an siRNA-based functional screen of all such transporters in the mouse genome. These studies will identify new aspects of the Salmonella-host cell interaction, shed light on the role of mammalian metal transporters in Salmonella infection, and suggest novel approaches to treating salmonellosis.

描述（由申请人提供）：沙门氏菌会引起人类急性胃肠炎或全身性发热性疾病伤寒。这两种综合症都是全世界重大的公共卫生问题。沙门氏菌和哺乳动物细胞之间导致细菌入侵和细胞内生长的相互作用取决于细菌和宿主因素。铁、镁和锰等金属离子在这些相互作用中发挥着重要作用。参与这些金属的结合或运输的细菌蛋白质的突变对沙门氏菌的毒力有重大影响。相应地，哺乳动物二价金属转运蛋白 Nrampl 的突变导致沙门氏菌感染的易感性增加。基于这些观察结果，我假设除 Nramp1 之外的哺乳动物金属转运蛋白也可能影响沙门氏菌与宿主细胞的相互作用。为了支持这一观点，我提出了初步证据，表明铁外排蛋白铁转运蛋白 1 (FPN1) 是溶质载体 (SLC) 转运蛋白家族的成员，其中包括 Nramp1，当在 HeLa 细胞中表达时，可显着抑制沙门氏菌的细胞内生长。本提案中的实验将把这一研究范围扩展到：（a）通过检查 FPN1 的亚细胞定位、其铁转运功能在抑菌中的参与及其对铁运动的影响，阐明 FPN1 的抑菌作用机制。进入或离开吞噬体。 (b) 阐明 FPN1 在巨噬细胞内沙门氏菌生长中的作用，巨噬细胞是这种生物体在全身性疾病中长期感染的细胞类型，使用 siRNA 技术敲低该蛋白的表达，(c) 识别其他金属通过对小鼠基因组中所有此类转运蛋白进行基于 siRNA 的功能筛选，我们发现 SLC 家族的离子转运蛋白可能会影响沙门氏菌的细胞内生长。这些研究将确定沙门氏菌与宿主细胞相互作用的新方面，阐明哺乳动物金属转运蛋白在沙门氏菌感染中的作用，并提出治疗沙门氏菌病的新方法。

项目成果

Siderocalin inhibits the intracellular replication of Mycobacterium tuberculosis in macrophages.

• DOI: 10.1111/j.1574-695x.2009.00622.x
• 发表时间: 2010-02
• 期刊: FEMS immunology and medical microbiology
• 作者: Johnson EE;Srikanth CV;Sandgren A;Harrington L;Trebicka E;Wang L;Borregaard N;Murray M;Cherayil BJ
• 通讯作者: Cherayil BJ