IMMUNOREGULATORY EFFECTS OF ESTROGEN IN EAE

描述（由申请方提供）：17 β-雌二醇（E2）治疗可预防实验性自身免疫性脑脊髓炎（EAE）的临床和组织学体征，EAE是多发性硬化症（MS）的动物模型。E2抑制海洋T细胞的活化、细胞因子（特别是TNF-α）和趋化因子的产生以及致脑炎活性，并防止炎性细胞募集到CNS中。在过去的授权期间，我们证明了缺乏Esr1（E2的α受体）但不缺乏Esr2（E2的β受体）的小鼠对E2介导的慢性EAE抑制是难治的，从而暗示了Esr7在E2介导的保护中。此外，我们发现E2处理并不直接抑制致病性T细胞。E2条件Esrf+树突状细胞（DC）转移到Esr1敲除小鼠完全抑制EAE，表明DC代表至少一个关键的E2敏感细胞类型。E2通过Esr1上调FoxP3的表达，增强CD4 + CD25 + Treg细胞的调节活性。重要的是，E2处理的DC既降低了ARC激活致脑炎T细胞的功能，又增强了CD4 + CD25 + FoxP3 + Treg细胞的诱导。E2的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多态性相关。虽然我们最近的研究结果缩小了E2预防EAE的候选人，但关键问题仍然存在，包括其他关键的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，与可以预防但不能治疗已建立的EAE的E2不同，用于口服避孕药的炔雌醇（EE）对EAE具有治疗作用，这提出了一个根本问题，即这种结构不同的分子是否通过Esr1发出信号并激活关键的E2敏感途径。我们在此提出检验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功能和增强CD4 + CD25 + FoxP3 + Treg细胞的活性来影响EAE的进程。因此，我们建议确定E2敏感的细胞类型，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。这些研究将明确确立EAE保护和治疗的E2和EE依赖性途径，这可能与MS患者未来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.