Optimizing Strategies to Overcome Kidney Xenograft Rejection

克服肾异种移植排斥的优化策略

基本信息

批准号：
9306769
负责人：
Andrew B Adams
金额：
$ 92.9万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2021-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9306769
关键词：
Acute Address Adverse effects American Antibodies Antigens Binding Biological Response Modifiers CD28 gene CD80 gene CD86 gene CRISPR/Cas technology CTLA4-Ig Carbohydrates Cell Adhesion Molecules Cell surface Cellular Immunity Clinic Clinical Complement Activation Critical Pathways Cytokine Signaling Data Development Enzymes Event Experimental Models Family suidae Future Galactose Gene Deletion Genes Genetic Genetic Engineering Genome engineering Graft Rejection HLA Antigens Heterophile Antigens Histocompatibility Antigens Class I Human Humoral Immunities IL2RB gene Immune response Immunity Immunologics Immunosuppression Immunosuppressive Agents Immunotherapeutic agent Infection Injury Integrin alpha4beta1 Kidney Kidney Transplantation Knock-out Life Malignant Neoplasms Mediating Modeling Modification Monkeys Mus Organ Organ Donor Organ Transplantation Pathway interactions Patients Play Pre-Clinical Model Primates Protocols documentation Publishing Reagent Recruitment Activity Regimen Reporting Resistance Risk Role Safety Savings Signal Transduction Source Sum System T cell response T-Cell Activation T-Cell Depletion T-Lymphocyte TNFRSF5 gene TNFSF5 gene Technology Testing Time Tissue Donors Tissues Toxic effect Transferase Transgenic Animals Transplantation Waiting Lists Work Xenograft procedure allograft rejection base clinical application clinical development clinical translation genome editing improved kidney xenograft next generation nonhuman primate novel novel strategies prevent response species difference targeted agent translational approach

项目摘要

With over 100,000 patients now on the waiting list for a kidney transplant it is obvious that there is a critical shortage of available donor organs. Xenotransplantation represents a promising solution. While pigs are viewed as the optimal non-human source of organs, the potency of the human immune response to pig organs has prevented the clinical application of pig-to-human kidney transplantation. In this application we propose using cutting-edge genetic engineering approaches in combination with the use of the next generation of agents targeting critical T cell costimulatory pathways to reduce both the humoral and cellular immune response of nonhuman primates (NHP) undergoing kidney transplantation as a preclinical model to inform future human trials. The first and dominant obstacle is the robust humoral immune response of primates to pig kidneys. Despite the gradual introduction of a number of genetic modification to pig donors including knocking out α-1,3-gal, the presence of pre-formed, naturally occurring antibodies as well as the de novo formation of xenoantigen-specific antibodies continues to result in early rejection. Here, we will use the powerful CRISPR/Cas9 system of genome editing to eliminate novel carbohydrate xenoantigens generated by the β4GAL-NT2 enzyme , and interrogate the impact of this gene deletion (layered onto GAL-/- hCD55 transgenic animals) on the survival of pig kidneys transplanted into NHP recipients. Beyond the humoral barrier to xenotransplantation, the robust cellular immune response to pig organs poses a second challenge to the clinical application of xenotransplantation. The development of immunosuppressive strategies based on the blockade of critical costimulatory signals that are required for T cell activation offers a potential strategy to more effectively control the cellular immune response with less toxicity in comparison to standard immunosuppressive regimens. However, current strategies targeting the two dominant costimulatory pathways, CD28 and CD154 using CTLA4-Ig and anti-CD154 mAb have been associated with issues of efficacy and safety. Importantly, our work has demonstrated the superior efficacy and safety of novel “next-generation costimulation blockers” compared to current costimulation blockers in both mouse and NHP models. Thus we will next interrogate the ability of these next generation reagents, or domain antibodies, to better control xeno- reactive immunity and prolong kidney xenograft survival. Finally, we will employ additional strategies that are synergistic with the blockade of T cell costimulation to consolidate graft acceptance: 1) genome-editing strategies to delete SLA class I/ class II on donor tissue and thereby mitigate T cell responses elicited via direct presentation following xenotransplantation, and 2) blockade of the cell adhesion molecule VLA-4 and cytokine signaling through CD122 as adjunct immunotherapeutic strategies to control the xeno-reactive, costimulation- independent T cell response xenotransplantation. In sum, this project uses cutting-edge technology to develop novel strategies to reduce both the humoral and cellular immunity barriers and prolong xenotransplant survival.

现在有超过100,000名患者在肾脏移植的等候名单上缺乏可用的供体器官。异种移植代表了一个有前途的解决方案。猪是被视为最佳的非人类器官来源，人类免疫反应对猪器官的效力已经阻止了猪到人类肾脏移植的临床应用。在此申请中，我们提出结合使用下一代的尖端基因工程方法靶向临界T细胞共刺激途径以减少体液和细胞免疫的药物非人类隐私（NHP）接受肾脏移植作为临床前模型的反应未来的人类试验。第一个和主导的障碍是对猪的强大的体质免疫反应肾脏。尽管对猪捐赠者进行了许多遗传修饰，包括敲门 α-1,3-gal，存在预先形成的，天然存在的抗体以及从头形成异种抗原特异性抗体继续导致早期排斥。在这里，我们将使用强大的 CRISPR/CAS9基因组编辑系统，以消除由新型的碳氢化物异种剂产生 β4GAL-NT2酶，并询问该基因缺失的影响（分层到GAL - / - HCD55转基因动物）关于移植到NHP接受者的猪肾存活。超越了壁式障碍异种移植，对猪器官的强大细胞免疫反应对异种移植的临床应用。基于 T细胞激活所需的关键共同刺激信号的封锁为潜在的策略提供了与标准相比，更有效地控制细胞免疫反应，毒性较小免疫抑制方案。但是，目前针对两种主要的共刺激途径的策略，使用CTLA4-Ig和抗CD154 MAB的CD28和CD154与效率和效率问题有关安全。重要的是，我们的工作证明了新的“下一代”的效率和安全性与当前的鼠标和NHP模型中当前的共刺激阻滞剂相比，共刺激阻滞剂”。接下来，将询问这些下一代试剂或域抗体的能力，以更好地控制Xeno- 反应性免疫和延长肾脏异种移植的存活。最后，我们将采用其他策略与T细胞共刺激的阻断以巩固接枝接受的协同作用：1）基因组编辑删除SLA II/ II类供体组织的策略，从而减轻通过直接引起的T细胞反应异种移植后的演示和2）细胞粘合分子VLA-4和细胞因子的阻滞通过CD122发出信号作为辅助免疫治疗策略，以控制异种反应性，共刺激 - 总而言之，该项目使用尖端技术来开发减少体液和细胞免疫障碍和延长异种移植生存的新型策略。