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

项目摘要： 项目1的目的是在压缩条件处理方案中使用多克隆受体Tclase， 嵌合和对死亡供体肾和/或胰岛的耐受性。胰岛移植治疗1型糖尿病 糖尿病（T1 D）目前受到低5年存活率的限制。胰岛存活率低可能是胰岛丢失的结果 这是由于同种免疫应答、复发性自身免疫和免疫抑制药物的毒性。因此， 从伦理上讲，治疗只能提供给患有危及生命的T1 D并发症的患者。诱导耐受性 通过混合嵌合体的发展， 自身免疫性胰岛丧失，以及对免疫抑制药物的需求。有几个障碍， 使用死亡供体诱导混合嵌合体和对肾脏和/或胰岛的耐受性，我们的目标是 克服我们目前的耐受性诱导方案，在食蟹猴中开发，并转化为 人类，涉及在器官移植之前免疫系统的6天调节，因此仅 适用于活体捐赠。以前试图将免疫调节压缩到24小时，以允许使用 不能诱导嵌合或耐受。此外，可能需要持久的嵌合体 用于逆转T1 D患者的自身免疫性，并且可能是治疗后最佳胰岛存活所必需的。 移植由于肾脏已被证明有助于在短暂嵌合体的情况下的耐受性， 更重要的是在没有共同移植的胰岛移植受体中获得持久的嵌合体 移植肾的移植我们现在有数据显示，扩增的多克隆受体 与以前相比，THBE可以实现显着延长的嵌合状态和更强大的耐受性 在食蟹猴模型中可能。我们假设，多克隆受体TdR的加入， 预先准备，压缩预处理方案，将允许混合嵌合体的发展 以及对肾脏和/或胰岛的耐受。我们的方法仅针对终末期肾病患者（Aim 1），患有T1 D和肾衰竭的患者（目标2A），最后是T1 D无肾衰竭（目标2B）。因此，我们认为， 如果在目标1中未实现持久嵌合体，则在目标2中添加其他措施。最后，准确 在非人中短暂或持久嵌合后耐受机制的表征 灵长类缺乏，在很大程度上是由于缺乏精确的工具来表征缺失和调控 机制等在目标3中，我们将使用标准免疫学检测结合高通量TCR 核心B中开发的CDR 3追踪系统（基于本实验室开发的人TCR平台 并针对食蟹猴进行了修改），以准确定量供体反应性效应T细胞的缺失/扩增。 细胞和供体特异性T细胞。胰岛将由核心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.