Blood-brain barrier traversal by African trypanosomes

描述：（由申请人提供）：睡眠的神经症状 由布氏冈比亚锥虫和 T b. 引起的人类疾病。罗德西亚群岛 归因于锥虫侵入中枢神经系统。 然而，非洲锥虫如何穿过血脑屏障（BBB）仍然是一个未知数。 未解决的问题。使用由人脑构建的体外 BBB 系统 我们已经启动了旨在破译微血管细胞（BMEC）的研究 非洲锥虫穿过血脑屏障的机制。初步研究 表明人类传染性 T. b.冈比亚血流形式寄生虫分离物 比动物感染性 T. b. 更有效地穿过体外 BBB 模型。 brucei 427.寄生虫似乎与细胞间的连接结合 BMEC。同样运动的原环形式既不结合也不穿过 障碍。更重要的是，BBB 紧密连接保持完整，这一发现 之前已经在体内描述过。抑制寄生虫 BBI3 蛋白酶抑制剂的交叉表明寄生虫蛋白酶在 血脑屏障渗透。我们的人类血脑屏障体外模型将成为一个重要的工具 了解非洲锥虫如何穿过血脑屏障。总体目标 这项研究将检验非洲锥虫的体外潜力 穿越宿主血脑屏障并解剖底层 机制。我们将描述相互作用的动力学 布氏锥虫的遍历。跨 BBB 体外模型。我们会 识别穿越障碍的方式；例如细胞旁或 跨细胞并检查寄生虫的潜在机制 和 BMEC 相互作用。从拟议的研究中获得的结果将是 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 设计阻止寄生虫进入大脑的疗法 预防许多令人痛苦的神经症状，这些症状最终导致 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.