The role of tolerogenic dendritic cells in islet-cell allograft transplantation

描述(由申请人提供)：大约7%的美国人口患有糖尿病，这是一种发病率和死亡率都很高的慢性病。胰岛细胞移植提供了一种理想的治疗方法，它将放弃对每日胰岛素注射和血糖监测的依赖，并将防止糖尿病的破坏性后果。树突状细胞(DC)可耐受免疫反应的发现预示了DC成熟抵抗(MR)在同种异体胰岛细胞移植中的潜在治疗价值。本建议旨在利用过继转移的维生素D3产生的MRDC来无限期延长胰岛细胞同种异体移植物的存活时间，并通过直接(T细胞识别供体MHC)和间接(T细胞识别自身MHC递呈供体别肽)途径来确定MRDC治疗对幼稚和记忆性CD4和CD8T细胞同种异体反应的影响。此外，该建议旨在研究过继转移的供体DC的命运，阐明供体DC被受体APC重新加工成同种异体抗原(Ag)的机制(S)，并确定由此产生的同种异体抗原呈递的持续时间。最后，本研究旨在研究抑制介质程序性细胞死亡配体1和吲哚胺2，3-双加氧酶在诱导同种异体移植耐受中的作用。这项研究利用多种类型的转基因小鼠来明确地研究上述目的，包括TCRtg小鼠，其CD4或CD8T细胞对同种异体抗原具有特异性。可使用的技术包括但不限于流式细胞术、免疫荧光染色和荧光显微镜、细胞培养、ELISA法、体内增殖试验和胰岛细胞移植。这项拟议的研究将评估DC疗法相对于其他细胞疗法的临床有效性，并设计将DC疗法与亚治疗免疫抑制剂联合使用以无限期延长胰岛细胞同种异体移植存活的方案。此外，它还将阐明体内耐受诱导的机制(S)，这是移植和自身免疫背景下的一个重要研究领域。 公共卫生相关性：糖尿病是一种毁灭性的慢性疾病，目前唯一可用的治疗方法是胰岛细胞移植。胰岛细胞移植的不成功很大程度上归因于用于预防同种异体移植排斥反应的免疫抑制剂的毒性。因此，开发基于细胞的治疗方法，通过诱导供者特异性耐受而不产生副作用来延长胰岛细胞移植的存活时间显然是有利的。

DESCRIPTION (provided by applicant): Approximately 7% of the US population suffers from diabetes, a chronic disease with significant morbidity and mortality. Pancreatic islet-cell transplantation poses an ideal therapy that would relinquish dependence on daily insulin injection and blood glucose monitoring, and would prevent the devastating consequences of diabetes. The discovery that dendritic cells (DC) can tolerize an immune response heralded the potential therapeutic value of DC rendered maturation resistant (MR) in islet-cell allograft transplantation. This proposal aims to use adoptively transferred vitamin D3 generated MRDC to indefinitely prolong islet-cell allograft survival, and to determine the effect of MRDC therapy on naive and memory CD4 and CD8 T cell alloresponses through the direct (T cells recognize donor MHC) and indirect (T cells recognize self-MHC presenting donor allopeptide) pathways of allorecognition. Further, this proposal aims to investigate the fate of adoptively transferred donor DC, elucidate the mechanism(s) by which donor DC are reprocessed by recipient APC into alloantigen (Ag), and determine the duration of alloAg presentation that results. Finally, it aims to study the role that the inhibitory mediators programmed cell death ligand 1 and indoleamine 2,3- dioxygenase play in inducing allograft tolerance. This study utilizes numerous types of genetically modified mice to definitively investigate the above stated aims, including TCRtg mice whose CD4 or CD8 T cells are specific for alloAg. Techniques to be used include but are not limited to flow cytometry, immunofluorescent staining and fluorescent microscopy, cell culture, ELISA, in vivo proliferation assay and islet-cell transplantation. The proposed study will allow for evaluation of DC therapy clinical utility over other cellular therapies, and for design of protocols using DC therapy in conjunction with sub-therapeutic immunosuppressive agents to indefinitely prolong islet-cell allograft survival. Further, it will elucidate the mechanism(s) of in vivo tolerance induction, an important area of research in the setting of transplantation and autoimmunity. PUBLIC HEALTH RELEVANCE: Diabetes is a devastating chronic disease for which the only currently available cure is islet-cell transplantation. The lack of success of islet-cell transplantation is largely attributable to the toxicity of immunosuppressive agents used to prevent allograft rejection. Therefore, the development of cellular based therapies that prolong islet-cell transplant survival by inducing donor-specific tolerance without side effects is clearly advantageous.