IFN-dependent macrophage-intrinsic innate resistance to Legionella pneumophila

虽然细胞内病原体，如嗜肺乳杆菌，操纵宿主细胞过程以建立细胞内生态位以维持其生存和复制，但宿主细胞已经进化出防御途径来限制感染。我们将研究由I型和II型ifn激活的细胞内先天耐药机制，该机制限制嗜肺乳杆菌感染。基于初步数据，我们假设两种类型的ifn都刺激抗菌蛋白定位到含军团菌液泡（LCV）。候选蛋白将通过IFNbeta和IFNgamma处理或未处理巨噬细胞LCVs的定量蛋白质组学分析来鉴定。这些蛋白的功能将通过siRNA介导的基因沉默、过表达和共聚焦显微镜来研究。对人类细胞的研究将验证IFN介导的耐药性的潜在弱点是否有助于人类细胞（和患者）对嗜肺乳杆菌感染的易感性。总的来说，该项目将提供对细胞内细菌的防御机制的见解，并将识别可能代表治疗干预新靶点的抗菌蛋白。

While intracellular pathogens, such as L. pneumophila, manipulate host cell processes in order to establish an intracellular niche for their survival and replication, host cells have evolved defense pathways to restrict the infection. We will examine an intracellular innate resistance mechanism activated by type I and II IFNs that restricts L. pneumophila infection. Based on preliminary data, we hypothesize that both types of IFNs stimulate the localization of antibacterial proteins to the Legionella containing vacuole (LCV). Candidate proteins will be identified by quantitative proteomic analyses of LCVs of IFNbeta and IFNgamma treated or untreated macrophages. The function of these proteins will be investigated by siRNA mediated gene silencing, overexpression and confocal microscopy. Studies of human cells will verify whether a potentially existing weakness of the IFN mediated resistance contributes to the susceptibility of human cells (and patients) towards L. pneumophila infection. Collectively, this project will provide insights in the defence mechanisms against intracellular bacteria and will identify antimicrobial proteins that might represent novel targets for therapeutic interventions.