Secondary Characterizations of Candidate F. tularensis NFkB Inhibitors

致病菌必须克服宿主的先天免疫屏障才能致病。干扰素 IFN γ和肿瘤坏死因子α（TNF α）是肿瘤生长早期和晚期产生的细胞因子。 免疫反应这些细胞因子的早期产生迅速激活炎症反应， 是抵御细菌入侵的第一道防线我们和其他实验室发现，土拉热弗朗西斯菌和 类鼻疽伯克霍尔德氏菌干扰NFicB活化（导致TNF α产生减少）和TNF α表达。 感染细胞对IFN γ的应答。我们假设，这些防御途径的破坏涉及 特定病原体基因产物（“效应物”）并促进由这些类别引起的感染和疾病 A和B胞质细菌病原体。我们已经开发了新的筛选技术，以确定 土拉热弗朗西斯菌和类鼻疽伯克霍尔德菌基因产物对宿主的破坏作用 IFN γ和NFicB应答。在我们的筛选中鉴定的效应蛋白将被研究它们对 免疫破坏和疾病。我们还将剖析它们的作用机制， 开发有助于筛选其功能抑制剂的分析方法。这些研究将奠定 为今后开展F.土拉菌和B. B. pseudomallei 感染.我们的具体目标是： (1)识别F。土拉菌和B. B.类鼻疽基因产物干扰先天免疫应答。 (2)工程突变体F.土拉菌和B. B.缺乏假定免疫抑制的假鼻疽菌株 基因，并在小鼠感染模型中测试这些突变对毒力的影响。 (3)确定巨噬细胞对IFN γ的应答中因感染F.土拉热。 我们将使用新的试剂和新技术来确定新的治疗靶点和减毒 疫苗株F.土拉菌和B. B.假鼻疽此外，通过展示这些技术如何 应用，我们的研究可能最终促进免疫识别和治疗靶向 调节来自其他选择因子和新兴病原体的毒力蛋白。这个研究项目符合 在细菌治疗的RMRCE综合研究重点中，将直接与RP（s）1.4相互作用， 1.5、2.1、2.5和2.6，并将利用核心C、E和F的资源。

To cause disease, pathogenic bacteria must overcome host innate immune barriers to infection. Interferon gamma (IFNy) and tumor necrosis factor alpha (TNFa) are cytokines produced both early and later in the immune response. Early production of these cytokines rapidly activates inflammatory responses to serve as a first line of defense against invading bacteria. We and other labs have found that Francisella tularensis and Burkholderia pseudomallei interfere with NFicB activation (causing reduced production of TNFa) and with the response of infected cells to IFNy. We hypothesize that subversion of these defense pathways involves specific pathogen gene products ("effectors") and promotes infection and disease caused by these category A and B cytosolic bacterial pathogens. We have developed novel screening technologies to identify the Francisella tularensis and Burkholderia pseudomallei gene products responsible for their subversion of host IFNy and NFicB responses. Effector proteins identified in our screens will be studied for their contributions to immune subversion and disease in infected animals. We will also dissect their mechanisms of action and develop assays that will facilitate screening for inhibitors of their functions. These studies will thus lay the foundation for future work to therapeutically impair establishment of F. tularensis and B. pseudomallei infections. Our Specific Aims are: (1) Identify F. tularensis and B. pseudomallei gene products interfering with innate immune responses. (2) Engineer mutant F. tularensis and B. pseudomallei strains deficient for putative immune-suppressive genes and test the effects of such mutations on virulence in mouse infection models. (3) Identify the stage in the macrophage response to IFNy that is impaired by infection with F. tularensis. We will use novel reagents and new technologies to identify novel therapeutic targets and attenuated vaccine strains in F. tularensis and B. pseudomallei. Further, by demonstrating how these technologies can be applied, our studies may ultimately promote the identification and therapeutic targeting of immune modulating virulence proteins from other select agents and emerging pathogens. This research project fits within the RMRCE Integrated Research Focus on Bacterial Therapeutics, will interact directly with RP(s) 1.4, 1.5, 2.1, 2.5, and 2.6, and will utilize the resources of Core(s) C, E, and F.