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）诱导狒狒对猪肾的耐受。 我们已经诱导了供体特异性T细胞无反应性，并阻止了抗供体抗体（Abs），但 尚未实现异种移植肾的长期存活。在上一个项目期间，我们确定了两个 实现这一目标的主要障碍，并制定了克服这些障碍的战略。（一）早期的外显缺失; 胸腺肾（TK）由于激活潜伏猪CMV（pCMV）;长期移植物存活恢复， 通过供体的剖腹产消除pCMV;和（ii）严重蛋白尿的发展;这 通过防止猪足细胞的SMPDL-3b依赖性破坏，可以延迟（但不能预防）问题 通过在围Tx期用利妥昔单抗治疗。目前正在处理的其余主要障碍 建议是：1）由于进行性蛋白尿最终发展为肾病综合征; 2）发展为 由于蛋白尿引起的免疫球蛋白丢失和可能的免疫球蛋白恢复不足引起的感染 猪胸腺移植物的保护性T细胞免疫。根据该团队开发的数据（项目2，3， （4）我们制定了克服这些障碍的创新战略。在目标1中，我们将首先确定 机制负责持续蛋白尿尽管利妥昔单抗治疗，并制定有效的治疗 战略布局我们已经发现，足细胞上SMPDL-3b的缺失和猪CD 80的上调都是由于 与异种移植肾病有关。我们的初步数据表明，利妥昔单抗，它结合到猪， 足细胞SMPDL-3B和抑制CD 80活化的贝拉西普都可以部分稳定蛋白质损失。的 最近的移植与这种联合治疗目前生存>70天，肌酐水平正常，只有 少量蛋白尿。我们的数据表明，物种间CD 47和SIRP-α的不相容性可能促进 先天免疫激活，在足细胞激活中达到高潮。在目标1中，我们将通过以下方式克服蛋白尿： 优化利妥昔单抗/CTLA-4 IG治疗，并使用hCD 47转基因（Tg）GalT-KO猪TK供体预防 狒狒巨噬细胞激活。在目标2中，我们将通过更快地重建异种移植物， 宿主和供体限制性保护性T细胞免疫。项目3中的研究证明了人类T细胞的局限性 在猪胸腺发育后的功能和体内平衡。我们将讨论的假设，这些 将通过向猪胸腺移植物中加入受体TEC与混合的 嵌合体我们现在将优化杂交胸腺移植物的构建，评估它们对免疫功能的影响， 并将该方案与项目2中开发的策略联合收割机结合，以实现持久的混合异种嵌合体 (Aim 3）。杂交胸腺移植和持久的混合嵌合体的结合将确保两者的耐受性 先天性和适应性免疫反应。该组合方法还将优化T细胞的功能， 对供体移植物和受体的感染的保护性免疫力，以及保护免受残余的 供体反应性T细胞和自身免疫。