Regulatory CD4/CD8 T cells in autoimmune demyelination

描述（由申请人提供）：免疫调节在控制成熟的自身反应性、潜在致病性T细胞中起关键作用。 不同的细胞成分和它们在调节机制中的相互作用还不清楚。 在这里，我们将研究如何一个显性负反馈机制控制髓鞘碱性蛋白（MBP）反应性V β 8.2 + T细胞介导的实验性自身免疫性脑脊髓炎的H-2u小鼠，多发性硬化症的原型。这种调节集中于分别通过调节性CD 8和CD 4 T细胞（Treg）识别I类和II类MHC背景中的TCR肽/MHC复合物。 我们已经提出（参见图1），CD 4 Treg在CD 8 Treg的募集/活化中提供帮助，其最终诱导活化的V β 8.2 + Th 1细胞的凋亡。致病性Th 1细胞的耗竭和非致病性Th 2细胞的扩增最终导致抗MBP应答的免疫偏离和对EAE的保护。 CD 4 Treg与框架3区肽BS反应，而CD 8 Treg识别来自TCR V β 8.2链的CDR 1/2区肽B3或p41-50。 使用CFSE标记的细胞的CDR 3长度谱分析或免疫镜分析和膜联蛋白-V染色，我们将确定体内诱导或生理调节后V β 8.2 + T细胞的命运。 我们将分别确定1型和2型细胞因子在调节的初始阶段和晚期阶段的作用。将产生CD 8 Treg克隆，并表征其MHC限制性、TCR-V基因使用和功能特性，包括其体外和体内的细胞溶解活性，以及其在过继转移后控制疾病的能力。我们将使用B10.PL.lpr、B10.PL.gld和B10.PL.perforin-/-小鼠确定CD 8 Treg的杀伤机制。这里涉及的免疫原理的知识不仅对于理解免疫调节的生物学，而且对于设计针对人类自身免疫性疾病的基于TCR的治疗方法都很重要。

DESCRIPTION (provided by applicant): Immune regulation plays a critical role in the control of mature self-reactive, potentially pathogenic T cells. Different cellular components and their interactions in regulatory mechanisms are not well understood. Here we will investigate how a dominant negative feedback mechanism controls myelin basic protein (MBP)-reactive Vbeta8.2+ T cells mediating experimental autoimmune encephalomyelitis in the H-2u mouse, a prototype for multiple sclerosis. This regulation is focused on the recognition of TCR peptide/MHC complexes in class I and II MHC contexts by regulatory CD8 and CD4 T cells (Treg) respectively. We have proposed (see Figure 1) that CD4 Treg provide help in the recruitment/activation of CD8 Treg, which ultimately induce apoptosis in activated Vbeta8.2+ Th1 cells. The depletion of pathogenic Th1 and expansion of non-pathogenic Th2 cells eventually leads to immune deviation of the anti-MBP response and protection from EAE. CD4 Treg are reactive to a framework 3-region peptide, BS, whereas CD8 Treg recognize the CDR1/2 region peptide, B3 or p41-50, from the TCR Vbeta8.2 chain. Using CDR3 length spectratyping, or immunoscope analysis and annexin-V staining of CFSE-labeled cells we will determine the fate of Vbeta8.2+ T cells following induced or physiological regulation in vivo. We will determine the role of type 1 and type 2 cytokines in the initial and late phases of regulation, respectively. CD8 Treg clones will be generated and characterized for their MHC-restriction, TCR-V gene usage and functional properties, including their cytolytic activity both in vitro and in vivo, and their ability to control disease upon adoptive transfer. We will determine the mechanism of killing by the CD8 Treg using B10.PL.lpr, B10.PL.gld and B10.PL.perforin-/- mice. Knowledge of the immune principles involved here is important not only for understanding the biology of immune regulation but also in the design of TCR-based therapeutic approaches for autoimmune conditions in humans.