KIDNEY RESTRICTED CTL AND ALLOGRAFT REJECTION

肾脏限制性 CTL 和同种异体移植物排斥

• 批准号: 2457796
• 负责人: GREGG A HADLEY
• 金额: $ 10.38万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2457796
• 关键词: CD8 molecule; MHC class I antigen; antigen presenting cell; biopsy; cell population study; cell type; cytolysis; cytotoxic T lymphocyte; flow cytometry; histocompatibility; homologous transplantation; human tissue; kidney transplantation; laboratory mouse; laboratory rat; liver cells; monoclonal antibody; transplant rejection; transplantation immunology

Despite the recent success of clinical organ transplantation, the immunologic destruction of allografts remains a significant problem. We have recently identified a novel type of cytolytic T lymphocyte (CTL) that recognizes MHC class I alloantigens in a kidney-restricted manner; i.e., these alloreactive CTL lyse kidney cell targets at high levels but show little reactivity to lymphoid cell targets. Previous studies of CTL activity have utilized lymphoid targets almost exclusively; consequently, the fundamental characteristics of parenchymal cell-restricted effector populations and their role in allograft rejection are unknown. Our ultimate goal is to determine the role of parenchymal cell-restricted effector populations in the clinical rejection of organ transplants. To facilitate the investigation of these issues, we have established a mouse model of kidney-restricted allorecognition. We have already isolated and characterized mouse CTL-KR clones, and have now established that CTL-KR dominate the murine CTL response to allogeneic kidney cells in vitro. The current proposal will utilize rodent models to elucidate five key aspects of CTL-KR immunobiology. Highly-focused clinical studies can then follow to verify relevance to the human system. To determine if CTL-KR can mediate tissue-detruction in vivo, mouse CTL-KR clones will be tested for the capacity to destroy functional elements of the kidney following injection under the kidney capsule. Rat kidney transplant models that mimic acute, delayed, and chronic allograft rejection will be used to define the in vivo conditions that elicit CTL-KR; the spontaneous kidney- restricted lytic activity of graft infiltrating cells will be examined in these experiments. Human CTL-KR clones will be propagated from clinical rejection biopsies to verify that they have the same properties as those from the mouse and normal humans. Limiting dilution analyses will be used to quantitate the contribution of CTL-KR to the total alloreactive CTL repertoire, and to determine if CTL-KR are elicited by conventional APC. To determine which cell types present within a graft elicit tissue- restricted CTL, purified populations of parenchymal cells (hepatocytes, keritinocytes, pancreatic islets) and leukocytes (macrophages, B-cells, and dendritic cells) will be tested for the capacity to elicit kidney- restricted CTL responses; CTL generation assays will be used to define the costimulatory requirements for activation of CTL-KR from purified CD8+ T- cell precursors. Monoclonal antibodies to T-cell differentiation antigens will be used in FACS analysis and CTL blocking studies to determine if CTL- KR utilize tissue-restricted accessory molecule/ligand interactions for target cell lysis; mHC-associated peptides will be isolated from kidney cells and tested for the capacity to sensitize lymphoid cells to lysis by CTL-KR. Together, these experiments will provide important new information on the cellular basis of clinical graft loss.

尽管临床器官移植最近取得了成功，但 同种异体移植的免疫学破坏仍然是一个重大问题。 我们 最近已经确定了一种新型的细胞溶解淋巴细胞（CTL） 以肾脏限制的方式识别MHC I类同种抗原； IE。， 这些同种异体反应性CTL裂解肾细胞靶标高水平，但显示 对淋巴样细胞靶标的反应性很小。 CTL的先前研究 活性几乎完全利用了淋巴靶标。最后， 实质细胞限制效应子的基本特征 种群及其在同种异体移植排斥中的作用尚不清楚。 我们的 最终目标是确定实质细胞限制的作用 效应子种群在器官移植的临床排斥反应中。 到 促进对这些问题的调查，我们建立了鼠标 肾脏受限的同种识别的模型。 我们已经孤立了， 表征了鼠标CTL-KR克隆，现在已经确定了CTL-KR 在体外，主导对同种异体肾细胞的鼠CTL反应。 这 当前的建议将利用啮齿动物模型阐明五个关键方面 CTL-KR免疫生物学。 高度关注的临床研究可以进行 验证与人类系统的相关性。 确定CTL-KR是否可以 将在体内介导组织 - 渗透性，将测试小鼠CTL-KR克隆 销毁肾脏功能元素的能力 在肾脏胶囊下注射。 大鼠肾脏移植模型 模拟急性，延迟和慢性同种异体移植排斥将用于 定义引起CTL-KR的体内条件；自发的肾脏 - 将检查移植细胞的受限裂解活性 这些实验。 人CTL-KR克隆将从临床中传播 拒绝活检以验证其具有与之相同的特性 来自老鼠和正常人。 将使用限制稀释分析 量化CTL-KR对总同种反应性CTL的贡献 曲目，并确定CTL-KR是否是通过常规APC引起的。 确定移植物中存在哪些细胞类型会引起组织 - 受限的CTL，纯化的实质细胞群体（肝细胞， 角蛋白形成细胞，胰岛）和白细胞（巨噬细胞，B细胞和 树突状细胞）将测试引起肾脏的能力 限制CTL响应； CTL生成测定将用于定义 从纯化的CD8+ T-激活CTL-KR的共刺激要求 细胞前体。 T细胞分化抗原的单克隆抗体 将用于FACS分析和CTL阻塞研究，以确定CTL-是否是否 KR利用组织限制的辅助分子/配体相互作用 靶细胞裂解； MHC相关的肽将从肾脏中分离出来 细胞并测试了通过通过 CTL-KR。 这些实验将共同提供重要的新信息 在临床移植损失的细胞基础上。