IMMUNOREGULATORY EFFECTS OF ESTROGEN IN EAE

描述(申请人提供)：17β-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(尤其是肿瘤坏死因子-α)和趋化因子的产生，以及脑源性活动，并阻止炎症细胞向中枢神经系统募集。在过去的授予期间，我们证明了缺乏ESR1(E2的α受体)而不是Esr2(E2的β受体)的小鼠对E2介导的慢性EAE的抑制是无效的，因此暗示Esr7参与了E2介导的保护。此外，我们还发现，E2处理并不直接抑制致病T细胞。将E2条件下的ESRF+树突状细胞(DC)转移到ESR1基因敲除小鼠体内可完全抑制EAE，表明DC代表至少一种关键的E2敏感细胞类型。此外，我们还发现E2可以上调FoxP3的表达，并通过ESR1增强CD4+CD25+Treg细胞的调节活性。重要的是，经E2处理的DC既降低了激活脑源性T细胞的ARC功能，又增强了对CD4+CD25+FoxP3+Treg细胞的诱导。可以解释E2保护作用的一个机制是它显著上调DC巨噬细胞、B细胞和T细胞上的PD-1(程序性死亡-1)标记，这一发现与最近描述的与MS疾病进展相关的PD-1基因多态性有关。尽管我们最近的结果缩小了有助于预防EAE的E2的候选因素，但关键问题仍然存在，包括其他关键的E2敏感细胞类型以及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确立的EAE的E2不同，用于口服避孕药的乙基雌二醇(EE)对EAE具有治疗作用，这提出了一个基本问题：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。我们在这里提出的假设是，E2介导的保护和EE介导的治疗主要涉及ESR1依赖的APC和Treg细胞，这些细胞通过增强PD-1的表达、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，我们建议确定对于Esr7介导的EAE保护至关重要的E2敏感细胞类型，评估PD-1及其配体在保护机制中的作用，并在EAE复发、慢性和自发模型中区分EE和E2的治疗和神经保护作用。这些研究将清楚地建立依赖于E2和EE的EAE保护和治疗途径，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.