Mechanisms of lymphocyte transmigration across the blood-brain barrier using an in vitro model that mimics blood flow and simulates inflammatory conditions as observed in the most frequent autoimmune disorder of the central nervous system, multiple sclero

使用体外模型模拟血流并模拟在中枢神经系统最常见的自身免疫性疾病多发性硬化症中观察到的炎症状况，从而研究淋巴细胞跨血脑屏障的迁移机制

• 批准号: 235301825
• 负责人: Dr. Birgit Obermeier, Ph.D.
• 金额: --
• 依托单位: Department of Cell Biology
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/235301825?language=en
• 关键词: Mechanisms; lymphocyte; transmigration; across; blood

Multiple sclerosis (MS) is a common neurological disease with about 2,000,000 people affected worldwide. The infiltration of autoreactive immune cells into the central nervous system is a crucial step in its pathogenesis as these cells cause injury to the brain tissue. Proof of principle comes from drugs like Natalizumab that prevent immune cells from crossing the blood-brain barrier (BBB) and provide benefit for patients. However, the mechanisms of cell trafficking across the BBB remain incompletely resolved. The aim of the proposed project is to study cellular transmigration in more detail. For that purpose, Dr. Ransohoff and his team have developed an in vitro model of the BBB which represents the in vivo situation very well. It comprises a tight monolayer of human brain microvascular endothelial cells which is exposed to cytokines that simulate inflammation. Further, shear forces are incorporated to mimic physiological blood flow. Previous studies in the lab using this model revealed that monocytes, but not lymphocytes, adhered efficiently on the inflamed endothelium upon encounter with the chemokine CXCL12 although both cell types expressed the appropriate chemokine receptor CXCR4 (Man S et al., 2012). Unexpectedly, monocyte arrest gave rise to the transmigration of T and B cells. We hypothesize that monocyte-endothelial interactions promote secretion of factors (chemokines, cytokines, proteolytic enzymes) which render the endothelial surface permissive for interaction with lymphocytes. We will test this hypothesis and address related questions using our innovative flow-based in vitro BBB model. First, we will examine molecular modulations of the endothelium after monocyte arrest. Next, we will ask whether those monocyte-mediated changes of the endothelial surface promote lymphocyte transmigration. We also take into account that lymphocytes may be capable to transmigrate without the help of monocytes but in the presence of a chemokine that selectively signals to lymphocytes. We aim to identify such an arrest chemokine specific for lymphocytes in our project. In addition, video microscopy will be used in order to visualize and characterize kinetics of interactions between endothelium, monocytes and lymphocytes under flow. Results arising from that research may reveal new perspectives on the development of selective therapeutics that prevent infiltration of autoreactive immune cells in MS.

多发性硬化症(MS)是一种常见的神经系统疾病，全球约有200万人受到影响。自身反应性免疫细胞渗入中枢神经系统是其发病机制中的关键一步，因为这些细胞会对脑组织造成损伤。原理的证据来自于像Natalizumab这样的药物，这些药物可以防止免疫细胞越过血脑屏障(BBB)，并为患者提供好处。然而，跨血脑屏障的细胞贩运机制仍未完全解决。拟议项目的目的是更详细地研究细胞的轮回。为此，兰索霍夫博士和他的团队开发了一种血脑屏障的体外模型，该模型很好地代表了体内的情况。它由一层紧密的人脑微血管内皮细胞组成，暴露在模拟炎症的细胞因子中。此外，还加入了剪切力以模拟生理血流。使用该模型的实验室先前的研究表明，尽管两种细胞都表达适当的趋化因子受体CXCR4，但单核细胞，而不是淋巴细胞，在遇到趋化因子CXCL12时，能有效地黏附在炎症的内皮细胞上(曼、S等，2012年)。出乎意料的是，单核细胞停滞导致了T和B细胞的迁移。我们假设单核细胞与内皮细胞的相互作用促进了因子(趋化因子、细胞因子、蛋白水解酶)的分泌，从而使内皮细胞表面允许与淋巴细胞相互作用。我们将使用我们创新的基于流动的体外血脑屏障模型来检验这一假说并解决相关问题。首先，我们将研究单核细胞停滞后内皮细胞的分子调控。接下来，我们将询问这些单核细胞介导的内皮表面变化是否促进了淋巴细胞的迁移。我们还考虑到，淋巴细胞可能能够在没有单核细胞的帮助下，但在有选择性地向淋巴细胞发出信号的趋化因子存在的情况下进行转生。我们的目标是在我们的项目中确定这样一种针对淋巴细胞的趋化因子。此外，视频显微镜将用于可视化和表征血流作用下内皮细胞、单核细胞和淋巴细胞之间的相互作用的动力学。这项研究的结果可能揭示出选择性疗法的发展的新视角，这种疗法可以防止自身反应性免疫细胞在MS中的渗透。