Attacking anthrax action by blocking receptor signaling

描述（由申请人提供）：申请R21，NOT-AI-02-023，生物防御和新发传染病研究 从炭疽杆菌中分离出的炭疽毒素进入人体细胞并破坏细胞功能。 该毒素由受体结合组分、可与酶组分、水肿因子（EF）和/或致死因子（LF）缔合以形成炭疽毒素的保护性抗原（PA）组成。 毒素结合介导毒素复合物内化的细胞表面受体。 最近，来自John Young和John Collier实验室的工作鉴定了炭疽毒素的受体，命名为炭疽毒素受体（ATR;布拉德利等人，2001年）。 由于炭疽毒素造成伤害的能力取决于受体结合，因此靶向炭疽受体可能提供额外的治疗方法，即使在疑似接触炭疽孢子后也可能有用。 在许多情况下，细胞表面受体下游的信号传导涉及蛋白质和脂质激酶的活化。 小分子激酶抑制剂Gleevec在慢性粒细胞白血病中的成功应用表明，靶向激酶可能提供治疗各种疾病的有效手段。 本项目的目标是研究ATR信号通路，以确定作为抑制靶点的关键效应分子。 ATR在介导毒素内化中的作用将在哺乳动物细胞中使用生物化学和免疫荧光方法进行解剖。 斑马鱼将被用作动物模型来研究体内ATR功能，并评估其作为测试旨在阻断毒素作用的药物的动物模型的潜力。 申请人有3个具体目标，将与Young和Collier实验室合作进行。 目标1. 探讨炭疽受体胞浆区在潜在治疗干预中的作用。 目标二。 探讨炭疽热受体在斑马鱼正常胚胎发育过程中的生理作用。 目标3. 检查斑马鱼中的炭疽毒性，以用作药物或疫苗测试的额外廉价模型系统。

DESCRIPTION (provided by applicant): Application for R21, NOT-AI-02-023, Biodefense and Emerging Infectious Diseases Research Anthrax toxin, isolated from the bacterium, Bacillus anthracis, enters human cells and disrupts cellular function. The toxin consists of a receptor binding component, protective antigen (PA) which can associate with the enzymatic components, edema factor (EF) and/or lethal factor (LF) to form the anthrax toxin. The toxin binds a cell surface receptor which mediates the internalization of the toxin complex. Recently, work from the laboratories of John Young and John Collier identified the receptor for the anthrax toxin, named the anthrax toxin receptor (ATR; Bradley et al., 2001). Since the ability of the anthrax toxin to cause harm is dependent upon receptor binding, targeting the anthrax receptor might provide additional therapies that could be useful even after suspected exposure to anthrax spores. In many cases, signaling downstream of cell surface receptors involves the activation of protein and lipid kinases. Successful use of the small molecule kinase inhibitor Gleevec in chronic myelogenous leukemia has shown that targeting kinases might provide an efficient means to treat various diseases. This goal of this project is to study the ATR signaling pathway in order to identify key effector molecules as targets for inhibition. The role of ATR in mediating toxin internalization will be dissected using biochemical and immunofluorescence methods in mammalian cells. The zebrafish will be used as an animal model to study ATR function in vivo and to assess its potential as an animal model for testing drugs aimed at blocking toxin action. The applicant has 3 specific aims which will be undertaken in collaboration with the Young and Collier labs. Aim 1. To investigate the role of the cytoplasmic domain of the anthrax receptor for potential therapeutic intervention. Aim 2. To determine the physiological role of the anthrax receptor by functional interference during normal embryonic development in the zebrafish. Aim 3. To examine anthrax toxicity in the zebrafish for use as an additional inexpensive model system for drug or vaccine testing.