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）是一种异质性的脑自身免疫性炎症性疾病。拟议研究的长期目标是开发改进的动物模型，以了解和治疗疾病亚型，特别是那些严重的疾病亚型。具体目的是评估CD8 T淋巴细胞在介导EAE疾病表型严重程度中的作用。该假说认为，自反应性Th1 CD4 T淋巴细胞引发中枢神经系统（CNS）炎症后，在特定的关键时期，随后的实质CD8 T淋巴细胞募集导致更严重的临床疾病。为了验证这一假设，我们在（C57BL6xB10.PL） F1小鼠身上建立了EAE的过继转移模型。初步数据表明，与B10.PL小鼠相比，过继性转移髓鞘碱性蛋白（MBP）特异性（Acl-11） Th1 CD4 T淋巴细胞可诱导免疫正常（C57BL6xB10.PL） F1小鼠发生严重的EAE。组织学表征、基因表达分析和CD8缺失揭示了CD8细胞毒性T淋巴细胞（CTL）在（C57BL6xB10.PL） F1小鼠中的致病作用。这些结果表明，依赖于遗传背景，CD8 T淋巴细胞可以调节疾病的严重程度。我们的假设将在三个具体目标中得到进一步的验证。在Aim 1中，我们计划使用CD8缺陷和CTL效应缺陷小鼠来阐明CD4和CD8 T淋巴细胞在急性病变中的致病作用。Aim 2的重点是确定严重EAE早期发展中CD8 T淋巴细胞进入的关键时期和相关的CNS微环境变化。在Aim 3中，我们建议分离CNS特异性CD8 T淋巴细胞克隆，在体外对其进行表征，并评估其诱导CNS炎症性疾病的能力。这些研究将更好地理解中枢神经系统炎症性脱髓鞘疾病中ctl介导的损伤。此外，该EAE模型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，具有临床意义。由于CTL可能在急性MS病变中引发轴突损伤，从而导致慢性进行性临床缺陷，因此该模型也可用于筛选抑制CD4 T淋巴细胞引发炎症的潜在MS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.