FUNCTION OF MHC MOLECULES IN DEMYELINATING DISEASE

描述：（改编自申请人摘要）：MHC II类（Ia） 小胶质细胞上的分子是许多脱髓鞘疾病的共同标志 包括阿尔茨海默病、亨廷顿病、帕金森病和 多发性硬化 我们建议在两个小鼠模型中研究小胶质细胞的激活， 脱髓鞘模型，抽搐小鼠，这是一个模型，为克拉布s 神经毒素诱导的小鼠疾病和铜腙治疗 脱髓鞘 本提案的目的是确定机制， 哪些MHC II类分子激活小胶质细胞， 小胶质细胞激活对神经病理学的影响 具体目标有三个： 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加重脑梗死患者脱髓鞘的机制 抽搐模型不清楚。 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， 随后脱髓鞘的严重程度增加。 我们已经获得了 I-Ab截短的胞质尾区，其中信号传导结构域已被 删除. 这些I-Ab截短的小鼠将与抽搐小鼠交配， 产生I-Ab截短的抽搐小鼠，并将这些小鼠与 野生型抽搐小鼠的临床症状、神经病理学和小胶质细胞 参与。 2）。 确定Ia分子的胞质结构域是否起作用 在体外小胶质细胞信号转导中的作用。 MHC II类分子可以 作为其他细胞类型的信号转导分子;然而， 在小胶质细胞中证明这一点很重要。 我们将构建 和功能分析，以测试I-Ab链的哪个结构域是 负责激活小胶质细胞 此外，我们将使用primary 来自I-Ab-截短的、I-Ab-/-和野生型小鼠的小胶质细胞，并测试是否 参与的MHC II类分子的存在或不存在影响小胶质细胞 体外活化。 3）。 确定T淋巴细胞是否在神经退行性变中发挥作用， 抽搐的老鼠 该目标将解决T细胞参与免疫应答的问题。 twitcher小鼠。 虽然抽搐小鼠 很少表现出明显的T细胞浸润，其他人已经表明，很少 CNS中活化的T细胞可能仍然起重要作用。 我们将 直接评估T细胞的作用，通过交配抽搐小鼠到 缺乏成熟淋巴细胞的RAG-1缺陷小鼠， 脱髓鞘的结果。 另外，我们会将脾脏 将来自twitch小鼠的T细胞导入RAG-1缺陷型twitch小鼠，并测试T细胞是否 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.