Tr1-Specific Tolerance: a Novel Treatment of Multiple Sclerosis

描述（由申请人提供）： 我们正在开发一种新的免疫调节疗法，hR-411，用于治疗复发缓解型多发性硬化症（RRMS）。hR-411通过将致病性Th 1/Th 17细胞重定向为耐受诱导性Tr 1细胞来恢复调节性T细胞平衡。hR-411由人Ig-Fc和CXCL 11融合形成，CXCL 11是一种CXCR 3结合配体，最近被鉴定为反调节趋化因子。与促炎性CXCR 3结合配体CXCL 9和CXCL 10相反，体外暴露于CXCL 11的炎症效应Th 1和Th 17细胞将其极化重定向为抗炎Tr 1（FOXp 3-CD 25-IL-10 high）细胞。mR-411是hR-411的鼠同源物，即使在疾病发作后启动，也能显著抑制鼠EAE的神经学和组织学表现。这种复极化的持久性在过继转移研究中显示，其中从用mR-411体内处理的鼠EAE供体中分离的Ag特异性效应Th 1细胞抑制患有活动性疾病的受体中的EAE。与一般免疫抑制剂（类固醇、雷帕霉素、钙调磷酸酶抑制剂）相反，mR-411诱导对活动性疾病具有Ag特异性的耐受性，但保留了对不相关Ag的历史细胞介导的免疫。由于CXCL 11通过CXCR 3受体相互作用，因此预期其绕过MS中CD 4+细胞中的CD 46缺陷，并完全激活IL-10表达并诱导Tr 1细胞极化。为了支持这一假设，CXCL 11在体外与抗CD 28共孵育的人CD 4+细胞中强烈诱导IL-10表达。该授权的目的是建立mR-411在复发性MS的经典鼠EAE模型（“R-EAE”）中的药效学特征。待检验的科学假设是，mR-411通过抑制自身抗原特异性促炎性Th 1/Th 17应答的活化和分化（主要通过促进Tr 1细胞功能的活化）来降低R-EAE。目标一：在R-EAE小鼠模型中建立mR-411的药效学特征将在R-EAE中检测mR-411（1、3或10 mg/kg QOD IP）或不相关IgG 1对照品的滴定，各组小鼠在疾病急性期（16-21天）后接受治疗。将这些处理组与未暴露于PLP 139 -151的阴性（假）对照组和用地塞米松处理的阳性对照组进行比较。将在1个月内监测动物是否出现明显的神经功能恶化。将检查脊髓组织是否存在炎症和组织损伤的组织学证据。目标二：确定mR-411降低R-EAE疾病严重程度的体内机制我们将检验mR-411治疗通过抑制自身抗原特异性Th 1/Th 17效应子应答的激活来降低EAE疾病严重程度的工作假设。将采用与目标#1相同的实验范例。我们将确定mR-411治疗如何改变治疗后CNS、脾脏和引流淋巴结中存在的CD 4 + Th 1/Th 17细胞的数量、表型、诱导和功能。这些研究将使用EAE的主动诱导和转移模型的组合，采用髓鞘特异性5 B6 PLP 139 -151特异性TCR转基因T细胞。 公共卫生相关性： 拟议的研究旨在确定一种假定的机制，通过这种机制，用mR-411（一种反调节耐受诱导趋化因子融合蛋白）治疗小鼠可能会增强调节性T细胞功能，从而特异性抑制复发缓解型多发性硬化症小鼠模型中自身反应性Th 1/17 T细胞的活性。这项工作对多发性硬化的病因学和治疗有重要意义。

DESCRIPTION (provided by applicant): We are developing a novel immunomodulatory therapy, hR-411, to treat relapsing-remitting multiple sclerosis (RRMS). hR-411 restores regulatory T-cell balance by redirecting pathogenic Th1/Th17 cells into tolerance- inducing Tr1 cells. hR-411 is formed from the fusion of human Ig-Fc and CXCL11, a CXCR3-binding ligand that has been recently identified as a counter-regulatory chemokine. In contrast to the pro-inflammatory CXCR3- binding ligands CXCL9 and CXCL10, in vitro exposure of inflammatory effector Th1 and Th17 cells to CXCL11 redirects their polarization into anti-inflammatory Tr1 (FOXp3-CD25-IL-10high) cells. mR-411, the murine homologue of hR-411, profoundly suppresses the neurological and histologic findings of murine EAE, even when initiated after disease onset. The durability of this repolarization is shown in adoptive transfer studies wherein Ag-specific effector Th1 cells isolated from murine EAE donors treated in vivo with mR-411 suppress EAE in recipients with active disease. In contrast to general immunosupresants (steroids, rapamycin, calcineurin inhibitors), mR-411 induces tolerance that is Ag-specific for active disease yet preserves historical cell-mediated immunity to unrelated Ag's. Because CXCL11 interacts via the CXCR3 receptor, it is expected to bypass the CD46 defect in CD4+ cells in MS and fully activate IL-10 expression and induce Tr1 cell polarization. In support of this assumption, CXCL11 strongly induces IL-10 expression in human CD4+ cells co-incubated in vitro with anti-CD28. The purpose of this grant is to establish the pharmacodyamic profile of mR-411 in a classic murine EAE model of relapsing MS ("R-EAE"). The scientific hypothesis to be tested is that mR-411 decreases R-EAE by inhibiting the activation and differentiation of autoantigen-specific pro-inflammatory Th1/Th17 responses predominantly by promoting the activation of Tr1 cell function. Aim #1: Establish a pharmacodynamic profile of mR-411 in a murine model of R-EAE A titration of mR-411 (1, 3, or 10 mg/kg QOD IP) or an irrelevant IgG1 control will be tested in R-EAE, with groups of mice receiving treatment after the acute phase of disease (16-21 days). These treatment groups will be compared to a negative (sham) control group not exposed to PLP139-151, and a positive control group treated with dexamethasone. Animals will be monitored for overt neurological deterioration over a period of 1 month. Spinal cord tissue will be examined for histologic evidence of inflammation and tissue injury. Aim #2: Determination of the in vivo mechanism by which mR-411 decreases disease severity in R-EAE We will test the working hypothesis that mR-411 treatment decreases EAE disease severity by inhibiting the activation of autoantigen-specific Th1/Th17 effector responses. The same experimental paradigm will be employed as in Aim #1. We wil determine how mR-411 treatment alters the number, phenotype, induction, and function of CD4+ Th1/Th17 cells present within the CNS, spleen, and draining lymph nodes following treatment. These studies will use a combination of actively induced and transfer models of EAE employing myelin-specific 5B6 PLP139-151-specific TCR transgenic T cells. PUBLIC HEALTH RELEVANCE: The proposed studies are designed to determine a putative mechanism by which treatment of mice with mR-411, a counter-regulatory tolerance-inducing chemokine fusion protein, may augment regulatory T cell function, thereby specifically suppressing the activity of autoreactive Th1/17 T cells in a mouse model of the relapsing remitting form of multiple sclerosis. This work has important implications for the etiology and treatment of multiple sclerosis.