Achieving Xenograft Tolerance through Thymic Programming in Primates

通过灵长类动物的胸腺编程实现异种移植耐受

• 批准号: 9073458
• 负责人: KAZUHIKO YAMADA
• 金额: $ 27.96万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9073458
• 关键词: Acids; Address; Adolescent; Antibodies; Autoimmunity; Autologous; B-Lymphocytes; Binding; CD47 gene; CD80 gene; CTLA4-Ig; Cell physiology; Cesarean section; Chimerism; Collagen; Creatinine; Cytomegalovirus; Data; Development; Doctor of Philosophy; Edema; Engraftment; Family suidae; Funding; Gel; Goals; Graft Survival; Grant; Homeostasis; Human; Hybrids; Immune Tolerance; Immune response; Immunity; Immunoglobulins; In Vitro; Inbreeding; Infection; Kidney; Kidney Diseases; Kidney Transplantation; Lead; Life; Link; Macrophage Activation; Natural Killer Cells; Nephrotic Syndrome; Organ; Papio; Peripheral; Phenotype; Primates; Proteins; Proteinuria; Protocols documentation; Recovery; Regimen; Residual state; Serum; Solid; Sphingomyelinase; T-Lymphocyte; TNFRSF5 gene; Therapeutic; Thymic epithelial cell; Thymus Gland; Transgenic Organisms; Transplantation; Treatment Protocols; Up-Regulation; Xenograft procedure; adaptive immunity; base; bone; cytokine; design; effective therapy; humanized mouse; immune activation; immune function; improved; in vivo; innovation; kidney xenograft; podocyte; prevent; programs; protective effect; reconstitution; rituximab; thymus transplantation; tositumomab; treatment strategy

Project 1 aims to induce tolerance of porcine kidneys in baboons by co-transplantation (Tx) of vascularized thymus. We have induced donor-specific T cell unresponsiveness and prevented anti-donor elicited antibodies (Abs), but have not achieved long-term survival of xenograft kidneys. During the previous project period, we identified two major obstacles to this goal and developed strategies to overcome them. These are: (i) early loss of xeno- thymokidneys (TKs) due to activation of latent porcine CMV (pCMV); long-term graft survival was restored by elimination of pCMV through cesarean section of donors; and (ii) development of severe proteinuria; this problem could be delayed (but not prevented) by preventing SMPDL-3b-dependent disruption of pig podocytes through treatment with Rituximab in the peri-Tx period. The remaining major obstacles addressed in the current proposal are: 1) eventual development of nephrotic syndrome due to progressive proteinuria; and 2) development of infections due both to loss of immunoglobulins from proteinuria and presumably insufficient recovery of protective T cell immunity from porcine thymic grafts. Based upon the data developed by this team (Projects 2, 3, and 4), we have designed innovative strategies to overcome these obstacles. In Aim 1, we will first identify the mechanism responsible for continuing proteinuria despite Rituximab treatment and develop effective treatment strategies. We have found both loss of SMPDL-3b and upregulation of porcine CD80 on podocytes to be associated with xenograft nephropathy. Our preliminary data indicate that Rituximab, which binds to porcine podocyte SMPDL-3B and Belatacept, which inhibits CD80 activation, can both partially stabilize protein loss. The latest transplant with this combined therapy currently survives >70 days, with normal creatinine levels and only minimal proteinuria. Our data suggest that CD47 and SIRP-alpha incompatibility between species may promote innate immune activation that culminates in podocyte activation. In Aim 1, we will overcome proteinuria by optimizing Rituximab/CTLA-4 Ig therapy and using hCD47 transgenic (Tg) GalT-KO pig TK donors to prevent baboon macrophage activation. In Aim 2, we will achieve xenograft tolerance with more rapid reconstitution of host- and donor-restricted protective T cell immunity. Studies in Project 3 demonstrated limitations in human T cell function and homeostasis following development in a pig thymus. We will address the hypothesis that these abnormalities will be corrected by adding recipient TEC to the porcine thymus graft combined with mixed chimerism. We will now optimize the construction of hybrid thymic grafts, assess their impact on immune function and combine this protocol with strategies developed in Project 2 to achieve durable mixed xenogeneic chimerism (Aim 3). The combination of hybrid thymic grafting and durable mixed chimerism will assure tolerance of both innate and adaptive immune responses. The combined approach will also optimize functions of T cells providing protective immunity against infections for the donor graft and recipient and of Tregs that protect against residual donor-reactive T cells and autoimmunity, respectively.

项目1旨在通过血管化胸腺的共移植（TX）诱导鲍氏肾脏的耐受性。 我们已经诱导了供体特异性的T细胞无响应性，并阻止了抗抑制抗体（ABS），但 尚未实现异种移植肾脏的长期生存。在上一个项目期间，我们确定了两个 这一目标的主要障碍并制定了克服它们的策略。这些是：（i）Xeno-早期丧失 由于激活潜在的猪CMV（PCMV），胸腺虫（TKS）；长期移植生存已通过 消除PCMV通过剖宫产捐助者部分； （ii）发生严重蛋白尿；这 可以通过防止SMPDL-3B依赖性猪足细胞的破坏来延迟（但不能阻止）问题 通过利妥昔单抗治疗在THE-TEX时期。电流中剩下的主要障碍 建议是：1）由于进行性蛋白尿而导致的肾病综合征的最终发展； 2）发展 由于蛋白尿中的免疫球蛋白丧失以及可能不足以恢复的感染 猪胸腺移植物的保护性T细胞免疫。基于该团队制定的数据（项目2，3， 4），我们设计了创新的策略来克服这些障碍。在AIM 1中，我们将首先确定 尽管治疗了利妥昔单抗，但仍能继续蛋白尿并发展有效治疗的机制 策略。我们发现SMPDL-3B的损失和猪CD80在足细胞上的上调 与异种移植肾病有关。我们的初步数据表明利妥昔单抗与猪结合 抑制CD80激活的Podocyte SMPDL-3B和Belatacept都可以部分稳定蛋白质损失。这 目前使用这种联合疗法的最新移植量> 70天，肌酐水平正常，仅 最小蛋白尿。我们的数据表明，物种之间的CD47和Sirp-Alpha不兼容可能会促进 先天免疫激活，最终在足细胞激活中。在AIM 1中，我们将通过 优化利妥昔单抗/CTLA-4 Ig疗法并使用HCD47转基因（TG）Galt-Ko Pig TK供体来防止 狒狒巨噬细胞激活。在AIM 2中，我们将实现异种移植的耐受性，并更快地重构 宿主和供体限制的保护性T细胞免疫。项目3中的研究表明了人类T细胞的局限性 猪胸腺发育后的功能和稳态。我们将解决以下假设 通过将受体TEC添加到猪胸骨移植中，将纠正异常 嵌合体。现在，我们将优化混合胸腺移植物的构建，评估它们对免疫功能的影响 并将该协议与项目2中制定的策略相结合，以实现耐用的混合异构嵌合嵌合体 （目标3）。混合胸腺嫁接和耐用的混合嵌合体的结合将确保两者的耐受性 先天和适应性免疫反应。合并的方法还将优化提供T细胞的功能 防止供体移植物和受体的感染的保护性免疫力，以及防止残留的Tregs 供体反应性T细胞和自身免疫性。