Modulating chemokine receptors at the blood-brain barrier under flow

描述（由申请人提供）：本研究提案的目的是确定穿过血脑屏障（BB B）如何调节外周血单核细胞（PBMC）（包括T细胞、B细胞和单核细胞）上的趋化因子受体表达。该研究策略利用了一种新颖独特的体外血脑屏障模型，并结合了流动条件。总的假设是，个别趋化因子受体的调节不同的白细胞亚群，视配体的可用性;白细胞谱系;和白细胞活化状态。这项研究的表现将在两个方面推进当前的知识：首先，我们将获得新的信息，在流动条件下的PBMC与独特的脑血管内皮细胞相互作用的趋化因子受体的调节;第二，我们将能够解释组织浸润细胞的趋化因子受体表达所揭示的炎症人类中枢神经系统（CNS）的免疫组织化学研究。具体目标是：1。确定管腔“阻滞”趋化因子如何调节迁移细胞上趋化因子受体的表达。这些研究将纳入来自健康志愿者和接受那他珠单抗的MS患者的PBMC，在这些患者中，趋化因子受体与配体的结合与停滞和迁移解偶联。2.为了确定近腔的“穿越”趋化因子如何在蛋白质和mRNA水平上调节穿越细胞上的趋化因子受体表达。这些知识将确定特定的趋化因子受体作为治疗神经炎性疾病的突出治疗靶点。 公共卫生相关性：血脑屏障（BBB）由直接穿过大脑并滋养大脑的专门血管组成。这些专门的血管限制有害物质的进入，并促进葡萄糖等有益成分的进入。此外，BBB限制免疫细胞进入大脑，无论是在防御细菌的过程中，还是在炎症性疾病如多发性硬化症（MS）的情况下。这里的“底线”是免疫细胞使用一套特殊的“规则”穿过BBB进入大脑。这些“规则”对应于免疫细胞表面的分子，如果我们要开发安全有效的方法来减少有害的免疫细胞进入并在有益时促进免疫细胞进入，那么识别这些分子至关重要。在这个研究项目中，我们建议利用一个新开发的体外（组织培养）模型的血脑屏障。该模型结合了血脑屏障的主要元素：专门的血管细胞，流动的培养基（模拟血液）和人类免疫细胞和分子。将使用复杂的分析方法来研究这些细胞，这些细胞在进入系统的“大脑”侧后可以恢复。我们将使用这个系统来描绘免疫细胞亚群用来穿过BBB的“规则”，我们还将测试哪些分子在穿过后留在细胞表面。这些结果将增加关于这一重要过程的新知识，也将有助于我们解释前几年的研究。这些知识对于我们在MS和其他疾病期间安全有效地阻止免疫细胞进入大脑至关重要。

DESCRIPTION (provided by applicant): The goal of this research proposal is to establish how crossing the blood-brain barrier (BBB) regulates chemokine receptor expression on peripheral blood mononuclear cells (PBMC) including T cells, B cells and monocytes. The research strategy utilizes a novel and unique model of the BBB in vitro, incorporating flow conditions. The overall hypothesis is that individual chemokine receptors are regulated differentially on different subsets of leukocytes, contingent on ligand availability; leukocyte lineage; and leukocyte activation state. Performance of this research will advance current knowledge in two ways: first, we will gain new information about chemokine receptor modulation under flow conditions as PBMC interact with the unique cerebrovascular endothelium; second we will be enabled to interpret chemokine receptor expression by tissue-infiltrating cells as revealed by immunohistochemistry studies of the inflamed human central nervous system (CNS). The Specific Aims are: 1. To establish how luminal 'arrest' chemokines modulate chemokine receptor expression on transmigrated cells. These studies will incorporate both PBMC from healthy volunteers and from MS patients receiving natalizumab, in whom chemokine receptor engagement with ligand is uncoupled from arrest and transmigration. 2. To determine how abluminal 'transmigration' chemokines regulate chemokine receptor expression on transmigrated cells both at the protein and mRNA levels. This knowledge will identify specific chemokine receptors as salient therapeutic targets to treat neuroinflammatory diseases. PUBLIC HEALTH RELEVANCE: The blood-brain barrier (BBB) consists of specialized vessels which course directly through, and nourish, the brain. These specialized vessels limit the entry of noxious substances and promote access for beneficial components such as glucose. In addition, the BBB restricts entry of immune cells into the brain both during defense against germs and in the setting of inflammatory diseases such as multiple sclerosis (MS). The 'bottom line' here is that immune cells use a special set of 'rules' to enter the brain across the BBB. These 'rules' correspond to molecules on the immune cell surface and identifying these molecules is critical if we are to develop safe, effective ways to reduce harmful immune cell entry and promote immune-cell entry when it's beneficial. In this research project, we propose to utilize a newly-developed in-vitro (tissue culture) model of the BBB. This model incorporates the major elements of the BBB: specialized blood vessel cells, flowing culture medium (mimicking blood) and human immune cells and molecules. Sophisticated analytic methods will be used to study the cells, which can be recovered after they've crossed into the 'brain' side of the system. We will use this system to delineate the 'rules' which subsets of immune cells use to cross the BBB, and we will also test which molecules remain on the cell surface after crossing. These results will add new knowledge about this important process, and will also help us to interpret studies done in previous years. This knowledge is essential as we move towards safely and effectively blocking immune-cell movement into the brain during MS and other diseases.