IMMUNOREGULATORY EFFECTS OF ESTROGEN IN EAE

描述（由申请人提供）：用17 - β -雌二醇（E2）治疗可以预防实验性自身免疫性脑脊髓炎（EAE）的临床和组织学症状，EAE是多发性硬化症（MS）的动物模型。E2抑制海洋T细胞的激活、细胞因子（尤其是tnf - α）和趋化因子的产生以及致脑活性，并阻止炎症细胞进入中枢神经系统。在过去的给药期间，我们证明缺乏Esr1 （E2的α受体）而没有Esr2 （E2的β受体）的小鼠对E2介导的慢性EAE抑制难以耐受，从而暗示Esr7参与E2介导的保护。此外，我们发现E2治疗并不能直接抑制致病性T细胞。将E2条件的Esrf+树突状细胞（DC）转移到Esr1敲除小鼠中，完全抑制了EAE，表明DC至少代表了一种关键的E2敏感细胞类型。此外，我们发现E2可以通过Esr1上调FoxP3的表达，增强CD4+CD25+ Treg细胞的调控活性。重要的是，e2条件DC既降低了ARC激活脑源性T细胞的功能，又增强了对CD4+CD25+FoxP3+ Treg细胞的诱导。E2保护作用的一种机制是其显著上调DC巨噬细胞、B细胞和T细胞上的PD-1（程序性死亡-1）标志物，这一发现与最近描述的与MS疾病进展相关的PD-1多态性有关。尽管我们最近的研究结果缩小了E2预防EAE的候选范围，但关键问题仍然存在，包括额外的关键E2敏感细胞类型和PD-1在E2诱导的免疫调节中的作用。此外，与E2只能预防而不能治疗EAE不同，用于口服避孕药的乙炔雌二醇（ethinyl estradiol， EE）对EAE具有治疗作用，这就提出了一个根本性的问题，即这种结构不同的分子是否通过Esr1发出信号并激活E2敏感的关键通路。我们在此提出验证e2介导的保护和ee介导的治疗主要涉及Esr1依赖性APC和Treg细胞的假设，这些细胞通过增强PD-1表达、降低APC功能和提高CD4+CD25+FoxP3+ Treg细胞的活性来影响EAE的进程。因此，我们建议鉴定E2敏感细胞类型，这些细胞类型对esr7介导的EAE保护至关重要，评估PD-1及其配体在保护机制中的作用，并区分EE与E2在复发性、慢性和自发性EAE模型中的治疗和神经保护作用。这些研究将清楚地建立E2和EE依赖的EAE保护和治疗途径，这可能与未来MS患者的临床试验直接相关。

DESCRIPTION (provided by applicant): Treatment with 17beta-estradiol (E2) can prevent clinical and histological signs of experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis (MS). E2 inhibited activation, production of cytokines (particularly TNF-alpha) and chemokines, and encephalitogenic activity of marine T cells, and prevented recruitment of inflammatory cells into the CNS. During the past granting period, we demonstrated that mice lacking Esr1 (alpha receptor for E2) but not Esr2 (beta receptor for E2) were refractory to E2-mediated inhibition of chronic EAE, thus implicating Esr7 in E2-mediated protection. Moreover, we found that E2 treatment did not directly inhibit pathogenic T cells. Transfer of E2-conditioned Esrf+ dendritic cells (DC) into Esr1 knockout mice completely suppressed EAE, indicating that DC represent at least one critical E2- sensitive cell type. Moreover, we found that E2 could up-regulate expression of FoxP3 and potentiate the regulatory activity of CD4+CD25+ Treg cells through Esr1. Of importance, E2-conditioned DC had both reduced ARC function for activating encephalitogenic T cells, and enhanced induction of CD4+CD25+FoxP3+ Treg cells. One mechanism that could account for the protective effects of E2 is its pronounced up-regulation of the PD-1 (programmed death-1) marker on DC macrophages, B cells and T cells, a finding relevant to a recently described PD-1 polymorphism associated with MS disease progression. Although our recent results have narrowed the candidates that contribute to E2 prevention of EAE, key issues still remain, including additional critical E2-sensitive cell types and the role of PD-1 in E2-induced immunoregulation. Moreover, unlike E2 that can prevent but not treat established EAE, ethinyl estradiol (EE) used in oral contraception has therapeutic effects on EAE, raising the fundamental question of whether this structurally different molecule signals through Esr1 and activates critical E2-sensitive pathways. We here propose to test the hypothesis that E2-mediated protection and EE-mediated therapy primarily involve Esr1- dependent APC and Treg cells that affect the course of EAE through enhanced PD-1 expression, reduced APC function, and heightened activity of CD4+CD25+FoxP3+ Treg cells. We thus propose to identify E2- sensitive cell types that are crucial for Esr7-mediated protection against EAE, evaluate the role of PD-1 and its ligands in the protective mechanism, and distinguish therapeutic and neuroprotective effects of EE vs. E2 in relapsing, chronic, and spontaneous models of EAE. These studies will clearly establish E2- and EE- dependent pathways of EAE protection and therapy that may have direct relevance for future clinical trials in MS patients.