Structure-Function Studies of Chemokines and Receptors

描述(申请人提供)：拟议研究的目标是在分子水平上了解趋化因子及其受体是如何控制细胞迁移和激活的。这些蛋白质是监视系统的一部分，该系统保护宿主免受病原体、细胞异常生长和其他生理侮辱的影响。然而，趋化因子或其受体的表达失控，细胞的渗透和激活有增无减，都会导致细胞损伤。因此，许多炎症性疾病，如类风湿性关节炎、哮喘、多发性硬化症和动脉粥样硬化，至少部分是由趋化因子引起的。趋化因子受体也被艾滋病毒用作细胞进入的一种手段。此外，在过去的几年里，人们已经认识到，许多其他临床上重要的病毒模仿、利用或靶向趋化因子和趋化因子受体，作为一种抑制宿主免疫反应的机制。因此，趋化因子及其受体现在被认为是治疗许多人类疾病的有吸引力的靶点。 为了了解这些蛋白质的功能，我们采取了结构、生物物理、生化和体内研究相结合的方法。具体地说，我们的目标是确定这些蛋白质的结构，了解受体结合和信号传递的分子细节，了解它们是否、如何以及为什么与细胞表面糖胺多聚糖(GAG)结合，以及病毒趋化因子蛋白如何操纵趋化因子系统。在这些基础研究的同时，我们试图确定作为受体拮抗剂的蛋白质变体，因此潜在的蛋白质疗法或试剂可以用于研究特定受体和趋化因子在疾病中的作用。该建议的具体目标如下： 1.研究趋化因子与糖胺聚糖相互作用的相关性和结构细节，重点研究趋化因子MCP-1。 2.确定趋化因子优先识别的特定GAG序列。 3.表征与MCP-1受体CCR2结合的额外趋化因子的受体结合、信号传递和GAG结合的细节。 4.对形成高阶低聚物和/或被GAGS寡聚的趋化因子进行结构调查，以研究寡聚的功能相关性和寡聚结构的多样性。 5.研究趋化因子与病毒趋化因子结合蛋白的相互作用。

DESCRIPTION (provided by applicant): The goal of the proposed research is to understand at a molecular level, how chemokines and their receptors control cellular migration and activation. These proteins are part of a surveillance system that protects the host from pathogens, abnormal cell growth, and other physiological insults. However, deregulated expression of chemokines or their receptors, and unabated infiltration and activation of cells, can cause cell damage. Thus many inflammatory diseases such as rheumatoid arthritis, asthma, multiple sclerosis and atherosclerosis are caused, at least in part, by chemokines. Chemokine receptors are also exploited by HIV as a means of cell entry. Furthermore, over the past few years it has been recognized that many other clinically important viruses mimic, exploit, or target chemokines and chemokine receptors as a mechanism for suppressing the host immune response. Chemokines and their receptors are therefore now considered attractive targets for the treatment of many human diseases. In order to understand how these proteins function, we take an approach that combines structural, biophysical, biochemical and in vivo studies. Specifically, our goals are to determine structures of these proteins, understand the molecular details of receptor binding and signaling, understand if, how, and why they bind to cell surface glycosaminoglycans (GAGs), and how viral chemokine proteins manipulate the chemokine system. In parallel with these fundamental studies we attempt to identify protein variants that are receptor antagonists, and therefore potential protein therapeutics or reagents that can be used to investigate the roles of specific receptors and chemokines in disease. The specific aims of the proposal are as follows: 1. Investigate the relevance and structural details of the interaction of chemokines with glycosaminoglycans, focusing on the chemokine MCP-1. 2. Identify specific GAG sequences that are preferentially recognized by chemokines. 3. Characterize the details of receptor binding, signaling and GAG binding of additional chemokines that bind to the MCP-1 receptor, CCR2. 4. Conduct a structural survey of chemokines that form higher order oligomers and/or that are oligomerized by GAGs to investigate the functional relevance of oligomerization and the diversity of oligomeric structures. 5. Characterize the interaction of chemokines with a viral chemokine binding protein.