EFFICACY OF COSTIMULATION BLOCKADE IN PREVENTING, TREATING ALLOGRAFT REJECTION

联合刺激阻断在预防和治疗同种异体移植排斥方面的功效

• 批准号: 6352624
• 负责人: ALLAN D KIRK
• 金额: $ 34万
• 依托单位: HENRY M. JACKSON FDN FOR THE ADV MIL/MED
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6352624
• 关键词: CD antigens; FK506; Macaca mulatta; biological models; biopsy; blocking antibody; bone marrow; cell adhesion molecules; cellular immunity; cyclosporines; cytokine; genetic transcription; homologous transplantation; humoral immunity; immunocytochemistry; immunosuppression; immunotherapy; interleukin 12; interleukin 2; kidney transplantation; mixed lymphocyte reaction test; monoclonal antibody; nonhuman therapy evaluation; polymerase chain reaction; prednisone; skin transplantation; transplant rejection; transplantation immunology

Successful allotransplantation currently requires continuous administration of immunosuppressive medication to prevent immunological graft rejection. These drugs are expensive and their non-specific effects greatly increase the risk of infection and malignancy. Therapies with long lasting, antigen specific effects have thus been sought. Recently, it has been shown that T cells can be made specifically non-reactive by allowing for T cell receptor engagement while preventing signaling through co- stimulatory receptors including CD28 and possibly CD154. We have initiated extensive studies in non-human primates showing that monoclonal antibodies (Mabs) that block CD154 prevent and treat allograft rejection and that their effects appear, preliminary, to be long lasting and graft specific. Additional study has been initiated with agents that block CD28 activation by interrupting its association with its ligands CD80 and CD86. The role of this project will be to investigate Mabs that block the function of CD28 and CD154 in an applicable pre-clinical model and to provide information for the design of a clinical trial with these promising agents. We will utilize a well established rhesus monkey renal allograft model to study the efficacy and safety of induction with costimulation blocking agents alone and in combination with conventional agents. Extensive collaboration with project 2 will ensure that transplants will be performed between animals with defined donor and recipient MHC disparity. We will monitor the potential side effects of each agent, and optimize the duration and dosing of each induction regimen. We will test for allograft tolerance using secondary skin grafts from donor and third party animals complemented by assays for immune competence to environmental antigens. We will investigate the mechanism of costimulation blockade induced graft acceptance. We will assay the intragraft cytokine milieu by RT-PCR and with project 2 by immunohistochemistry. Particular attention will be directed to the intragraft transcription of cytokines, costimulation molecules, and adhesion molecules associated with ischemia re-perfusion injury. Peripheral donor-specific immune responses will be studied by mixed lymphocyte reaction, allo-antibody determination, limiting dilution analysis and cytotoxicity assays. We will also test whether graft acceptance established by costimulation blockade is dependent on the suppressed expression of Th1 cytokines IL-2 and IL-12. Using neutralizing antibodies against IL-12 and the administration of recombinant IL-2 and IL-12, the ability of these cytokines to reverse the effects of costimulation blockade will be assessed during induction and after prolonged graft survival. We will also apply mechanistic concepts derived from project 4 in vivo. In collaboration with project, we will test whether co-administered donor-specific hematopoietic stem cells at the time of transplantation promote graft acceptance, and adapt the methods for expansion of primitive marrow derived stem cells to the rhesus model. We will transition the most successful method for preventing graft rejection into clinical trials planned with project 2 and project 3 investigators.

目前成功的同种异体移植需要持续 服用免疫抑制药物以预防免疫反应 移植排斥反应。这些药物价格昂贵且作用非特异性 大大增加感染和恶性肿瘤的风险。治疗方法长 因此，人们寻求持久的、抗原特异性的效果。近日，有 研究表明，T 细胞可以通过允许特定的非反应性 用于 T 细胞受体接合，同时防止通过 co- 刺激受体包括 CD28 和可能的 CD154。我们已发起 对非人灵长类动物的广泛研究表明，单克隆抗体 (Mab) 阻断 CD154 预防和治疗同种异体移植排斥 初步看来，它们的效果是持久的且具有移植特异性。 已开始针对阻断 CD28 激活的药物进行更多研究 通过中断其与其配体 CD80 和 CD86 的结合。角色 该项目的目的是研究阻断以下功能的单克隆抗体 CD28和CD154在适用的临床前模型中并提供 设计具有这些前景的临床试验的信息 代理。我们将利用成熟的恒河猴肾同种异体移植物 研究共刺激诱导的有效性和安全性的模型 单独使用封闭剂以及与常规试剂组合。 与项目 2 的广泛合作将确保移植 在具有明确供体和受体 MHC 的动物之间进行 差距。我们将监测每种药物的潜在副作用，并且 优化每个诱导方案的持续时间和剂量。我们将测试 使用来自供体和第三次的二次皮肤移植来实现同种异体移植耐受 派对动物辅以免疫能力测定 环境抗原。我们将研究共刺激的机制 封锁诱导移植物接受。我们将检测移植物内细胞因子 通过 RT-PCR 检测环境，并通过免疫组织化学检测项目 2。特别的 注意力将集中在细胞因子的移植内转录， 共刺激分子和与缺血相关的粘附分子 再灌注损伤。外周供体特异性免疫反应将 通过混合淋巴细胞反应、同种抗体测定进行研究， 有限稀释分析和细胞毒性测定。我们也会测试 是否通过共刺激阻断建立的移植物接受 依赖于 Th1 细胞因子 IL-2 和 IL-12 表达的抑制。 使用针对 IL-12 的中和抗体并施用 重组IL-2和IL-12，这些细胞因子能够逆转 将在诱导期间评估共刺激阻断的效果 移植物长期存活后。我们还将应用机械概念 源自体内项目4。通过与项目合作，我们将 测试是否共同施用供体特异性造血干细胞 移植时间促进移植物接受，并适应 将原始骨髓干细胞扩增至恒河猴的方法 模型。我们将转变最成功的预防移植方法 项目 2 和项目 3 计划的临床试验被拒绝 调查人员。