A Novel Therapy for Restricted Induction of Tolerance to Treat Diabetes Mellitus

描述(申请人提供)：我们正在开发一种新的免疫调节方法来阻止新发的1型糖尿病(T1D)患者的胰岛损伤并恢复特异性免疫耐受。T1D患者胰岛损伤可能与致病Th1/Th17细胞过多、耐受诱导抗原特异性Treg(Foxp3+CD25+)和TR1CD4+细胞(Foxp3-CD25-IL-10High)缺乏有关。由于缺乏合适水平的TR1细胞，致病激活的Th1/Th17细胞无对抗性，导致胰岛细胞的损伤和破坏。我们的方法将自身免疫激活的Th1/Th17细胞的极化重定向到诱导耐受的TR1细胞，其基础是研究表明，输注体外产生的抗原特异性TR1细胞在自身免疫的实验模型中具有保护作用，如实验性T1D和胰岛细胞移植。然而，Th1细胞的体外复极化既繁琐又昂贵。在我们的活体方法中，我们父母给CXCL11(“MR-412”)，一种CXCR3结合的配体，我们最近发现是一种反调节趋化因子。用CXCL11的长效Fc融合蛋白(“MR-411”)治疗可以深刻抑制小鼠实验性变态反应性脑脊髓炎(EAE)，即使在疾病发作后开始治疗也是如此。此外，在过继转移实验中，MR-411体内处理的EAE供者体内分离的Ag特异性效应Th1细胞将其极化重定向至TR1细胞，并抑制EAE。与泛抑制性免疫调节剂不同，MR-411诱导对活动期疾病具有抗原特异性的耐受性，同时保持对先前遇到的抗原的普遍免疫力。我们现在试图扩大这些观察，并建立概念验证，即MR-412在T1D小鼠模型中建立了胰岛免疫耐受。具体目标#1：在自发性小鼠T1D模型中建立MR-412抢救糖尿病的有效性、剂量依赖性和持久性。从180日龄雌性糖尿病NOD小鼠开始，给予MR-412(0，4，40g/kg，ip 2X，每周1次)，连续18周，此时间点以高血糖为特征。在MR-412治疗停止时(急性组)或停止治疗12周后(恢复组)，直接终止小鼠。我们将检查胰岛损伤的组织学和免疫组织化学证据，并测定胰岛素含量。脾和胰腺将被检查：1)细胞内细胞因子在淋巴细胞中的表达，2)T细胞亚群的免疫组织化学鉴定和T-bet和STAT3的磷酸化。MR-412的血浆浓度将通过酶联免疫吸附试验测定，并与功能结果进行比较。我们预计MR-412将恢复正常血糖，直到恢复期结束。支持性数据将包括剂量依赖的证明，即MR-412对牺牲时收获的胰岛产生良好的生化和免疫效果，包括维持胰岛胰岛素含量，阻断T细胞渗透和T-bet磷酸化，以及STAT3磷酸化。

DESCRIPTION (provided by applicant): We are developing a novel immunomodulatory approach to arrest pancreatic islet injury and restore specific immune tolerance in new-onset Type 1 diabetes mellitus (T1D). Damage of pancreatic islets in T1D may result from excess pathogenic Th1/Th17 cells and deficient tolerance-inducing antigen (Ag)-specific Treg (FOXp3+CD25+) and Tr1 CD4+ cells (FOXp3-CD25- IL-10high). Lacking suitable levels of Tr1 cells, pathogenic activated Th1/Th17 cells are unopposed, resulting in islet cell damage and destruction. Our approach, which redirects the polarization of autoimmune-activated Th1/Th17 cells towards tolerance-inducing Tr1 cells, is grounded in research showing that the transfusion of ex vivo produced Ag-specific Tr1 cells is protective in experimental models of autoimmunity, such as experimental T1D and islet cell transplantation. Ex vivo repolarization of Th1 cells, however, is cumbersome and expensive. In our in vivo approach, we parentally administer CXCL11 ("mR-412"), a CXCR3-binding ligand that we have recently identified as a counter-regulatory chemokine. Therapy with a long-acting Fc fusion protein of CXCL11 ("mR-411") profoundly suppresses murine experimental allergic encephalomyelitis (EAE), even when initiated after disease onset. Moreover, Ag-specific effector Th1 cells isolated from EAE donors treated in vivo with mR-411 redirect their polarization into Tr1 cells and suppress EAE in adoptive transfer experiments. In contrast to pan-suppressive immunomodulators, mR-411 induces tolerance that is Ag-specific for the active disease yet preserves generalized immunity to previously encountered antigens. We now seek to extend these observations and establish proof-of-concept that mR-412 establishes immune tolerance of islets in a murine model of T1D. Specific Aim #1: Establish the potency, dose-dependence, and durability of mR-412 rescue therapy of well- established diabetes mellitus in a spontaneous murine T1D model. mR-412 (0, 4, 40 ?g/kg IP 2 X per week) will be dosed for 18 weeks to female diabetic NOD mice beginning at 180 days of age, a time point characterized by established hyperglycemia. Mice will be terminated either directly at the cessation of mR-412 therapy (acute group) or 12 weeks thereafter (recovery group). We will examine pancreases for histologic and immunohistochemical evidence of islet injury and determine insulin content. Spleen and pancreases will be examined for: 1) intracellular cytokine expression in lymphocytes, and 2) immunohistochemical identification of T cell subset infiltration and the phosphorylation of T-bet and STAT3. Plasma concentrations of mR-412 will be determined by ELISA and compared to functional outcomes. We expect that mR-412 will restore normoglycemia until the conclusion of the recovery period. Supportive data will include dose-dependent demonstration that mR-412 produces favorable biochemical and immunologic effects on islets harvested at the time of sacrifice, including the maintenance of islet insulin content, the blockade of T-cell infiltration nd T-bet phosphorylation, and STAT3 phosphorylation.