CD8 T Lymphocyte Regulation of EAE Disease Phenotype

描述（由申请人提供）：多发性硬化症及其动物模型，实验性自身免疫性脑脊髓炎（EAE），是一组异质性的自身免疫性脑部炎症疾病。拟议研究的长期目标是开发改进的动物模型来了解和治疗疾病亚型，特别是那些严重的疾病亚型。具体目标是评估 CD8 T 淋巴细胞在介导 EAE 疾病表型严重程度中的作用。该假设认为，在自身反应性 Th1 CD4 T 淋巴细胞引发中枢神经系统 (CNS) 炎症后，随后在特定关键时期实质内募集 CD8 T 淋巴细胞会导致更严重的临床疾病。为了检验这一假设，在 (C57BL6xB10.PL) F1 小鼠中开发了 EAE 过继转移模型。初步数据表明，与 B10.PL 小鼠相比，髓鞘碱性蛋白 (MBP) 特异性 (Acl-11) Th1 CD4 T 淋巴细胞的过继转移可在免疫活性 (C57BL6xB10.PL) F1 小鼠中诱导严重的 EAE。组织学特征、基因表达分析和 CD8 耗竭揭示了 (C57BL6xB10.PL) F1 小鼠中 CD8 细胞毒性 T 淋巴细胞 (CTL) 的致病作用。这些结果表明，根据遗传背景，CD8 T 淋巴细胞可以介导疾病的严重程度。我们的假设将在三个具体目标中得到进一步检验。在目标 1 中，我们计划使用 CD8 缺陷和 CTL 效应子缺陷小鼠来阐明 CD4 和 CD8 T 淋巴细胞在急性病变中的致病作用。目标 2 侧重于确定 CD8 T 淋巴细胞进入的关键期以及严重 EAE 早期发展中相关 CNS 微环境的变化。在目标 3 中，我们建议分离 CNS 特异性 CD8 T 淋巴细胞克隆，在体外表征它们，并评估它们诱导 CNS 炎症性疾病的能力。这些研究将有助于更好地了解 CTL 介导的中枢神经系统炎症、脱髓鞘疾病损伤。此外，该EAE模型具有临床意义，因为它更准确地反映了自身反应性CD4和CD8 T淋巴细胞在多发性硬化症急性脱髓鞘病变发病机制中的复杂作用。由于 CTL 可能引发急性多发性硬化症病变中的轴突损伤，从而导致慢性、进行性临床缺陷，因此该模型也应可用于筛选抑制 CD4 T 淋巴细胞引发的炎症的潜在多发性硬化症治疗方法以及 CTL 效应机制。

DESCRIPTION (provided by applicant): Multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), are a heterogeneous group of autoimmune, inflammatory diseases of the brain. The long-term goal of the proposed studies is to develop improved animal models to understand and treat disease subtypes, particularly those that are severe. The specific objective is to assess the role of CD8 T lymphocytes in mediating severity of EAE disease phenotype. The hypothesis is that, following initiation of central nervous system (CNS) inflammation by auto-reactive Th1 CD4 T lymphocytes, the subsequent parenchymal recruitment of CD8 T lymphocytes during a specific critical period leads to more severe clinical disease. To test this hypothesis, an adoptive transfer model of EAE was developed in (C57BL6xB10.PL) F1 mice. Preliminary data demonstrate that adoptive transfer of myelin basic protein (MBP)-specific (Acl-11) Th1 CD4 T lymphocytes can induce severe EAE in immune competent (C57BL6xB10.PL) F1 mice as compared to B10.PL mice. Histologic characterization, gene expression analysis, and CD8 depletion reveal a pathogenic role for CD8 cytotoxic T lymphocytes (CTL) in (C57BL6xB10.PL) F1 mice. These results suggest that, dependent on genetic background, CD8 T lymphocytes can mediate disease severity. Our hypothesis will be tested further in three Specific Aims. In Aim 1, we plan to use CD8-deficient and CTL effector-deficient mice to clarify the pathogenic roles of CD4 and CD8 T lymphocytes in acute lesions. Aim 2 focuses on defining the critical period of entry of CD8 T lymphocytes and associated CNS microenvironment changes in the early development of severe EAE. In Aim 3, we propose to isolate CNS-specific CD8 T lymphocyte clones, characterize them in vitro, and assess their ability to induce CNS inflammatory disease. These studies will provide a better understanding of CTL-mediated injury in inflammatory, demyelinating diseases of the CNS. In addition, this EAE model has clinical relevance because it more accurately reflects the complex roles of autoreactive CD4 and CD8 T lymphocytes in the pathogenesis of acute demyelinating lesions in multiple sclerosis. Since CTL's may initiate axonal injury in acute MS lesions with resultant chronic, progressive clinical deficits, this model should also be useful in screening potential MS therapeutics that inhibit CD4 T lymphocyte-initiated inflammation as well as CTL effector mechanisms.