TRANSPLANT IMMUNOMODULATION BY ALLOCHIMERIC MOLECULES

通过异种嵌合分子进行移植免疫调节

• 批准号: 6679033
• 负责人: Rafik MARK GHOBRIAL
• 金额: $ 13.34万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6679033
• 关键词: MHC class I antigen; T lymphocyte; antigen presentation; autoradiography; biotechnology; chimeric proteins; dendritic cells; epitope mapping; flow cytometry; genetic manipulation; hematopoietic growth factor; immune tolerance /unresponsiveness; immunogenetics; immunomodulators; laboratory rat; nonhuman therapy evaluation; transplant rejection; transplantation; transplantation immunology; western blottings

DESCRIPTION (provided by applicant): We seek to develop a clinically applicable strategy to induce "true" transplantation tolerance treated with allochimeric Class I MHC molecules. Our novel findings in a rat cardiac allograft model provide the foundation of this proposal. We hypothesize: (i) allochimeric-induced tolerance is applicable to genetically diverse allograft recipients; (ii) allochimeric molecules modulate the immune response by indirect presentation; (iii) aIlochimeric molecules generate unique regulatory T cells with distinctive functional and TcR allospecificities. We propose: 1. To Define the Requirements of Different AIIochimeric Molecules to Induce Tolerance. Multiple allochimeric molecules, in different strain combinations, will be constructed to define critical immunogenic epitopes in the polymorphic regions of class I MHC. AIIochimeric molecules that display donor-dominant epitopes on recipient class I antigens will be tested for their ability to induce "true" chronic rejection-free tolerance. 2. To Analyze AIIoimmune Modulation by Indirect Presentation of Allochimeric [alpha1h I/u]-RT1.Aa Class I MHC Molecules. Fine mapping of immunogenic/cryptic self-epitopes that are critical for allograft tolerance will be performed. Indirect allochimeric deviation of T cell responses will be addressed by employing host or donor-type dendritic cells that have been pulsed in vitro with donor wild-type or alpha1h 1/u]-RT1.Aa molecules. AIIochimeric protein labeling and detection will localize the site and cell-type involved in allochimeric processing and presentation. Requirement of 'immature vs mature' hepatic DC for allochimeric tolerance induction will be investigated in vivo by functional stimulation of DC maturity and allostimulatory capacity using FIt3L, a hematopoietic growth factor, to potentially abrogate indirectly induced tolerance following intra-portal allochimeric delivery. 3. To Characterize the Unique Population of Regulatory T Cells Induced by Indirect Allorecognition. We will perform in vivo and ex vivo phenotypic and functional characterization of regulatory T cells. Allochimeric generation of regulatory T cells, a possible key tolerogenic mechanism in this model, will be probed in vitro by studying immature hepatic dendritic cells that indirectly present allochimeric molecules to CD4+ T cells. Third, in vivo analysis of chronic rejection coupled with CDR3 spectrotyping, immunoscope and sequence analysis of allochimeric-induced clonally-restricted regulatory T cells will define unique T cell functional specificities and the influence of allochimeric sequence on the allospecific TcR repertoire.

描述（由申请人提供）： 我们试图制定一种临床上适用的策略，以诱导用同种元素I类MHC分子治疗的“真实”移植耐受性。我们在大鼠心脏同种异体移植模型中的新发现为该提案提供了基础。我们假设：（i）同种蛋白酶诱导的耐受性适用于遗传多样的同种异体移植受者； （ii）通过间接表现调节免疫反应； （iii）二胆料分子产生具有独特功能和TCR分配性的独特调节T细胞。我们提出：1。定义不同的Aiiochimeric分子诱导公差的要求。将在不同的应变组合中构建多个同种型分子，以在I类MHC的多态区域定义关键的免疫原性表位。在接受者I类抗原上显示供体主导表位的AIIOCHIMEREC分子将因其诱导“ True”慢性拒绝耐受性的能力进行测试。 2。通过间接表现同种型[alpha1h i/u] -RT1.AA I类MHC分子来分析AIIOMMUNE调制。将对同种异体移植耐受性至关重要的免疫原性自我射击的精细映射。通过使用宿主或供体类型的树突状细胞来解决T细胞反应的间接异源偏差，这些细胞已在体外与供体野生型或alpha1h 1/U] -RT1.AA分子进行体外脉冲。 AIIOCHIMERIC蛋白的标记和检测将定位与异素化处理和表现有关的位点和细胞类型。通过功能性刺激DC成熟度和使用FIT3L的功能性刺激DC成熟和同种异体刺激能力，将研究“未成熟与成熟”肝DC对同种型耐受性诱导的需求，该造血生长因子是一种潜在地消除了间接诱导的耐受性，在间接诱导的耐受性耐受性的耐受性。 3。为了表征通过间接同种识别引起的调节T细胞的独特群体。我们将进行调节T细胞的体内和离体表型和功能表征。在该模型中，将在体外研究未成熟的肝树突状细胞（间接地呈现给CD4+ T细胞）的未成熟肝树突状细胞，从而在体外探测同种型T细胞的同类产生调节T细胞。第三，对慢性排斥的体内分析以及CDR3光谱，免疫镜，以及对同种蛋白诱导的克隆限制的调节T细胞的序列分析将定义独特的T细胞功能特异性，以及同种聚会序列对同种孢子型TCR的影响。