ROLE OF CTL EFFECTOR MECHANISMS IN CHRONIC DEMYELINATION

JHM病毒（JHMV）感染导致急性脑脊髓炎 伴有原发性脱髓鞘在急性疾病期间， 部分无效，免疫反应发生在中枢神经系统内 系统（CNS）。无法产生杀菌免疫力导致 持续性CNS感染和慢性持续性脱髓鞘， 类似于多发性硬化症的病理特征两种主要 已经确定了病毒清除的效应子：细胞毒性T淋巴细胞 (CTL)介导的细胞溶解和干扰素γ（IFN-γ）。我们的工作 假设是CD 8 + T细胞，使用穿孔素介导的组合， 细胞溶解和IFN-γ分泌是主要的免疫效应系统 预防JHMV诱导的慢性脱髓鞘。为了理解这个角色 免疫反应从细胞中清除病毒， 感染（星形胶质细胞、少突胶质细胞和小胶质细胞），从而定义 有效预防持续性感染和慢性 这个项目有两个目标。第一部分分析了 穿孔素介导的细胞毒性。这是病毒中的主要效应子 从星形胶质细胞和小胶质细胞中清除。要完成的目标是CTL从 将IFN-γ KO（GKO）小鼠转移至感染的SCID、GKO/穿孔素 KO（GKO/PKO）和PKO接受者。GKO CTL表现出优异的穿孔性能 介导的细胞毒性，但不分泌IFN-γ。来自GKO捐赠者的CTL将 也被转移到感染的转基因小鼠中， 限制性因子（L/d）仅在少突胶质细胞上。第二个目的 确定IFN-γ对病毒清除的贡献， 持久性。IFN-γ似乎是参与病毒感染的效应器机制。 清除少突胶质细胞。这将通过转移 PKO供体的CTL向感染的SCID、PKO/GKO和GKO受体的转移。 病毒载量、特定细胞类型受到保护并进展为慢性 将分析感染和脱髓鞘。CTL衍生能力 IFN-γ改变少突胶质细胞复制的作用将通过 将PKO供体CTL转移到表达L/d的转基因小鼠中， 少突胶质细胞IFN-γ修饰感染的能力在 少突胶质细胞和星形胶质细胞将通过表达显性的 负性IFN-γ α链受体转基因，在 PLP和GFAP启动子。转基因表达将使这些细胞 特异性地抵抗IFN-γ信号传导事件。最后，瞬态 由DI载体驱动的来自感染细胞的IFN-γ表达将 确定IFN-γ对疾病早期进展的影响， 慢性脱髓鞘

JHM virus (JHMV) infection results in an acute encephalomyelitis accompanied by primary demyelination. During acute disease a vigorous, but partially ineffective, immune response occurs within the central nervous system (CNS). The inability to effect sterilizing immunity results in persistent CNS infection and chronic ongoing demyelination with many pathological hallmarks similar to multiple sclerosis. Two predominant effectors of virus clearance have been identified: cytotoxic T lymphocyte (CTL) mediated cytolysis and interferon gamma (IFN-gamma). Our working hypothesis is that CD8+ T cells, using a combination of perforin mediated cytolysis and IFN-gamma secretion are the major immune effector systems which prevent JHMV-induced chronic demyelination. To understand the role of the immune response in clearing virus from the cells which support infection (astrocytes, oligodendroglia and microglia) and thereby define the components effective in preventing persistent infection and chronic disease, this project has two aims. The first analyzes the contribution of perforin mediated cytotoxicity. This is the major effector in virus clearance from astrocytes and microglia. To accomplish is goal CTL from IFN-gamma KO (GKO) mice will be transferred to infected SCID, GKO/perforin KO (GKO/PKO) and PKO recipients. GKO CTL exhibit excellent perforin mediated cytotoxicity but secrete no IFN-gamma. CTL from GKO donors will also be transferred into infected transgenic mice expressing the restriction element (L/d) exclusively on oligodendroglia. The second aim determines the contribution of IFN-gamma to viral clearance and persistence. IFN-gamma appears to be effector mechanism involved in virus clearance from oligodendroglia. This will be accomplished by the transfer of CTL from PKO donors into infected SCID, PKO/GKO and GKO recipients. Virus load, specific cell types protected and progression to chronic infection and demyelination will be analyzed. The ability of CTL derived IFN-gamma to alter replication in oligodendroglia will be examined by transfers of PKO donor CTL into transgenic mice which express L/d on oligodendroglia. The ability of IFN-gamma to modify infection in oligodendroglia and astrocytes will be examined by expressing a dominant negative IFN-gamma alpha chain receptor transgene under the control of the PLP and GFAP promoters. Transgene expression will render these cells specifically resistant to IFN-gamma signaling events. Finally, transient IFN-gamma expression from infected cells, driven by a DI vector, will determine the effects of IFN-gamma on early progression of disease to chronic demyelination.