Using Polyclonal Tregs to Develop a Compressed BMT Regiment for Deceased Donor Islets and Kidneys

项目总结： 项目1旨在利用多克隆受体Tregs在压缩条件下实现混合方案 嵌合体和对已故供者肾脏和/或胰岛的耐受性。胰岛移植治疗1型糖尿病 糖尿病(T1D)目前受到低5年存活率的限制。胰岛存活率差很可能是胰岛丧失的结果 由于同种异体免疫反应，反复的自身免疫，以及免疫抑制药物的毒性。因此，这一点 治疗只能在伦理上提供给有危及生命的T1D并发症的患者。诱导耐受性 通过发展混合嵌合体的胰岛有可能消除同种异体免疫和 自身免疫性胰岛丧失，以及需要免疫抑制药物。要做到这一点有几个障碍 我们的目标是利用已故供者诱导对肾脏和/或胰岛的混合嵌合体和耐受性 克服困难。我们目前的耐受诱导方案是在食蟹猴身上开发的，并转化为 在器官移植之前，需要对免疫系统进行6天的调节，因此 适用于活体捐赠。之前尝试将免疫调节压缩到24小时，以允许使用 在已故捐献者中，未能引起嵌合体或耐受性。此外，可能需要持久的嵌合体。 以逆转T1D患者的自身免疫，从而可能是最佳胰岛存活所必需的 移植。由于肾脏已经被证明在短暂性嵌合体的情况下有助于耐受，所以它是 更重要的是，在不进行联合移植的胰岛移植受者中实现持久的嵌合体 如果要产生耐受性，就需要移植供体肾。我们现在有数据显示扩增的多克隆受体 Tregs可以实现显著延长的嵌合体和比以前更强大的耐受性 在食蟹猴模型中是可能的。我们假设多克隆受体Tregs的加入，可以 事先准备好的，压缩的条件反射方案，将允许混合嵌合体的发展 对肾脏和/或胰岛的耐受性。我们的方法仅针对终末期肾病患者(目的 1)，T1D合并肾功能衰竭患者(目标2A)，最后是无肾功能衰竭的T1D(目标2B)。因此， 如果目标1中没有实现持久的嵌合体，将在目标2中添加额外的措施。 非人短暂性或持久性嵌合体耐受机制的特征(S) 灵长类的缺失，在很大程度上是因为缺乏精确的工具来表征缺失和调控 机械装置。在目标3中，我们将使用标准免疫学分析结合高通量TCR 核心B开发的CDR3跟踪系统(基于本实验室开发的人类TCR平台 并针对食蟹猴进行了修改)以准确量化供体反应性效应器T的缺失/扩展 细胞和供体特异性树突状细胞。小岛将由核心A提供，并与项目2和核心合作 将通过核心C进行协调。

Project Summary: Project 1 aims to use polyclonal recipient Tregs in a compressed conditioning protocol to achieve mixed chimerism and tolerance to deceased-donor kidneys and/or islets. Islet transplantation for the cure of Type 1 diabetes (T1D) is currently limited by low 5-year survival rates. Poor islet survival is likely the result of islet loss due to alloimmune responses, recurrent autoimmunity, and toxicity from immunosuppressive drugs. Thus, this therapy can only ethically be offered to patients with life-threatening complications of T1D. Inducing tolerance to islets through the development of mixed chimerism has the potential to eliminate both alloimmune and autoimmune islet loss, as well as the need for immunosuppressive medications. There are several barriers to inducing mixed chimerism and tolerance to kidneys and/or islets using deceased donors that we aim to overcome. Our current tolerance induction regimen, developed in cynomolgus monkeys and translated to humans, involves a 6-day conditioning of the immune system prior to organ transplant and is therefore only applicable to living donation. Previous attempts to compress immune conditioning to 24 hours, to allow the use of deceased donors, failed to induce chimerism or tolerance. Additionally, durable chimerism may be required for reversal of autoimmunity in T1D patients and might then be necessary for optimal islet survival post- transplant. Since the kidney has been shown to contribute to tolerance in the case of transient chimerism, it is even more important to achieve durable chimerism in recipients of islet transplants without co-transplantation of a donor kidney if tolerance is to develop. We now have data showing that expanded polyclonal recipient Tregs can achieve markedly prolonged chimerism and more robust tolerance than has previously been possible in the cynomolgus model. We hypothesize that the addition of polyclonal recipient Tregs, that can be prepared in advance, to a compressed conditioning regimen, will permit the development of mixed chimerism and tolerance to kidneys and/or islets. Our approach targets patients with end-stage renal disease alone (Aim 1), patients with T1D and renal failure (Aim 2A), and finally T1D without renal failure (Aim 2B). Therefore, additional measures will be added in Aim 2 if durable chimerism is not achieved in Aim 1. Finally, accurate characterization of the mechanism(s) of tolerance following transient or durable chimerism in nonhuman primates is lacking, in large part due to the absence of precise tools to characterize deletional and regulatory mechanisms. In Aim 3, we will use standard immunologic assays combined with the high-throughput TCR CDR3 tracking system developed in Core B (based on the human TCR platform developed in this laboratory and modified for cynomolgus monkeys) to accurately quantify deletion/expansion of donor-reactive effector T cells and donor-specific Tregs. Islets will be provided by Core A and collaboration with Project 2 and the cores will be coordinated through Core C.