Blood-brain barrier traversal by African trypanosomes

描述：(申请人提供)：睡眠的神经症状 由布氏冈比亚锥虫和罗德赛锥虫引起的人类疾病是 归因于锥虫穿透中枢神经系统。 然而，非洲锥虫如何跨越血脑屏障(BBB)仍然是一个 未解决的问题。利用人脑构建的体外血脑屏障系统 微血管细胞(BMEC)我们已经启动了旨在破译 非洲锥虫跨越血脑屏障的机制。初步研究 显示人类感染性冈比亚结核杆菌血液形成寄生虫分离物 跨越体外血脑屏障模型的效率高于动物感染性T。 布鲁西427。寄生虫似乎与细胞间的连接结合在一起。 BMEC。同样能动的原环形式既不结合也不交叉 障碍。更重要的是，血脑屏障的紧密连接保持完好，这是一个发现 这在以前的活体实验中已经被描述过。寄生虫BBI3的抑制作用 蛋白水解酶抑制剂的交叉表明寄生虫蛋白酶在 血脑屏障穿透力。我们的人体血脑屏障体外模型将是一个重要的工具 了解非洲锥虫是如何跨越血脑屏障的。的总体目标 这项研究将检测非洲锥虫体外培养的潜力。 横穿宿主血脑屏障并解剖潜在的 机制(S)。我们将描述相互作用的动力学和 布氏锥虫(Trypanosoma brucei spp.跨越血脑屏障的体外模型。我们会 确定穿越屏障的模式；例如，细胞旁或 以及研究寄生虫的潜在机制(S) 和BMEC的相互作用。建议的研究结果将会是 我们对非洲锥虫最初事件的理解迈出了重要一步 侵入大脑。有了这些知识，我们将能够更好地 设计治疗方法，阻止寄生虫进入大脑和 预防许多令人痛苦的神经症状，这些症状最终会导致 死亡。

DESCRIPTION: (provided by the applicant): The neurological symptoms of sleeping sickness in man caused by Trypanosoma brucei gambiense and T b. rhodesiense are attributed to the penetration of the central nervous system by trypanosomes. Yet, how African trypanosomes cross the blood-brain barrier (BBB) remains an unresolved issue. Using an in vitro BBB system constructed of human brain microvascular cells (BMEC) we have initiated studies aimed at deciphering the mechanisms used by African trypanosomes to cross the BBB. Preliminary studies show that a human infective T. b. gambiense bloodstream form parasite isolate crossed the in vitro BBB model more efficiently than animal infective T. b. brucei 427. The parasites appeared to bind to intercellular junctions between BMEC. Equally motile procyclic forms do not bind or nor do they cross the barrier. More importantly, the BBB tight junctions remain intact, a finding that has been previously described in vivo. Inhibition of parasite BBI3 crossing by protease inhibitors suggests that parasite proteases play a role in BBB penetration. Our in Vitro model of the human BBB will be an important tool for understanding how African trypanosomes cross the BBB. The overall aims of this study will be to examine the in vitro potential of African trypanosomes to transverse the host blood-brain barrier and to dissect the underlying mechanism(s). We will characterize the kinetics of the interaction and traversal of Trypanosoma brucei spp. across an in vitro model of BBB. We will identify the mode of traversal of the barrier; e.g. paracellular or transcellular as well as examine the underlying mechanism(s) of the parasite and BMEC interactions. The results obtained from the proposed study will be a major step in our understanding of the initial events of African trypanosome invasion into the brain. Armed with this knowledge we will be better able to design therapies that will stop the parasites from entering the brain and prevent many of the agonizing neurological symptoms, which eventually lead to death.