FUNCTION OF MHC MOLECULES IN DEMYELINATING DISEASE

描述：(改编自申请者摘要)：MHC第二类(Ia) 小胶质细胞上的分子是许多脱髓鞘疾病的共同标志。 包括阿尔茨海默氏症、亨廷顿氏症、帕金森氏症和 多发性硬化症。我们建议对两只小鼠的小胶质细胞激活进行研究 脱髓鞘模型，抽动小鼠，这是克拉布S的模型 神经毒素所致小鼠的疾病和铜草酮治疗 脱髓鞘。这项提案的目的是通过以下方式确定机制 哪些MHC II类分子激活小胶质细胞以及 小胶质细胞激活对神经病理的影响。具体目标有三个方面： 1)。评估Ia分子是否介导信号转导以激活 体内的小胶质细胞。Ia加剧脑内脱髓鞘的机制 Twitcher模型尚不清楚。我们将确定信号转导是否 通过I-Ab链负责激活小胶质细胞和 随后脱髓鞘的严重程度增加。我们用小白鼠获得了 一个I-Ab-截短的细胞质尾巴，其中的信号域 已删除。这些I-Ab截短的小鼠将与Twitcher小鼠交配以 产生I-Ab截短的抽动小鼠，这些小鼠将与 野生型Twitcher小鼠的临床症状、神经病理和小胶质细胞 参与其中。 2)。确定Ia分子的细胞质结构域是否起作用 在体外小胶质细胞的信号转导中。MHC II类分子可以 作为其他类型细胞上的信号转导分子；然而，它 在小胶质细胞中证明这一点是很重要的。我们将构建我们的结构 和功能分析来测试I-Ab链的哪个结构域 负责小胶质细胞的激活。此外，我们还将使用主服务器 I-Ab-截短、I-Ab-/-和野生型小鼠的小胶质细胞 参与的MHC II类分子的存在或不存在会影响小胶质细胞 体外激活。 3)。确定T淋巴细胞是否在神经退行性变中起作用 抽动小鼠。这一目标将解决T细胞参与的问题 采用RAG-1基因敲除小鼠。尽管Twitcher老鼠 几乎没有表现出明显的T细胞浸润，其他人表现出很少 中枢神经系统中活化的T细胞仍可能发挥重要作用。我们会 通过与抽动小鼠交配直接评估T细胞对 RAG-1缺陷小鼠缺乏成熟淋巴细胞，并决定 脱髓鞘的结果。此外，我们还将采取脾移植的方式 Twitcher小鼠T细胞转化成RAG-1缺陷的Twitcher小鼠 细胞重建脱髓鞘的严重程度。

DESCRIPTION: (Adapted from Applicant's Abstract): MHC class II (Ia) molecules on microglia is a common hallmark of many demyelinating diseases including Alzheimer's disease, Huntington's disease, Parkinson's disease and multiple sclerosis. We propose to study microglial activation in two murine models of demyelination, the twitcher mouse which is a model for Krabbe s disease and cuprizone treatment of mice which is a neurotoxin-induce demyelination. The purpose of this proposal is to determine mechanisms by which MHC class II molecules activate microglia and the consequence of the microglial activation on neuropathology. The Specific Aims are threefold: 1). Assess if Ia molecules mediate signal transduction to activate microglia in vivo. The mechanism by which Ia exacerbates demyelination in the twitcher model is not clear. We will determine if signal transduction via the I-Ab chain is responsible for the activation of microglia and the subsequent increased severity on demyelination. We have obtained mice with a I-Ab-truncated cytoplasmic tail in which the signaling domain has been removed. These I-Ab truncated mice will be mated to twitcher mice to produce I-Ab-truncated twitcher mice and these mice will be compared to wildtype twitcher mice for clinical symptoms, neuropathology and microglial involvement. 2). Determine whether the cytoplasmic domain of the Ia molecule functions in signal transduction in microglia in vitro. MHC class II molecules can serve as signal transduction molecules on other cell types; however, it would be important to demonstrate this in microglia. We will us structure and functional analyses to test which domain of the I-Ab chain is responsible for microglial activation. In addition, we will use primary microglia from I-Ab-truncated, I-Ab-/- and wildtype mice and test whether the presence or absence of engaged MHC class II molecules affect microglia activation in vitro. 3). Determine whether T-lymphocytes play a role in neurodegeneration in the twitcher mice. This Aim will address the issue of T cell involvement in the twitcher mouse by using the RAG-1 knockout mice. Although the twitcher mice exhibit little apparent T cell infiltration, others have shown that few activated T cells in the CNS may still play an important role. We will directly assess the role of T cells by mating twitcher mice to the RAG-1-deficient mice which are devoid of mature lymphocytes and determine outcome of demyelination. In addition, we will adoptively transfer splenic T cells from twitcher mice into RAG-1-deficient twitcher mice and test if T cells reconstitute the severity of demyelination.