Genetic Modification of DCs as Immunotherapy for IDDM

描述(由申请人提供) 树突状细胞(DC)可以通过有效的途径敏化初始T细胞 呈递抗原，或者通过诱导抗原特异性来耐受T细胞 T细胞无能或调节性反应。分布式控制系统在很大程度上被忽视了，因为 IDDM的潜在治疗药物，因为它们被认为不是直接的 β细胞的杀手。值得注意的是，内毒素/抗CD40激活的DC表达高水平 膜相关的FasL，可诱导效应T细胞凋亡，以及 启动的促炎Th1细胞对FasL特别敏感。 此外，激活的DC会分泌抑制因子，如转化生长因子-β， 可下调T细胞和抗原提呈细胞的功能。 然而，基于内毒素/抗CD40激活的树突状细胞的免疫治疗缺乏抗原 特异性，这可能会导致全身免疫抑制。基因疗法提供了一种 设计DC以诱导调节性T细胞耐受的强大工具 β细胞抗原。我们的初步研究表明，内毒素/抗CD40 被激活的树突状细胞，已经被转染了编码β细胞的质粒 抗原，在体内诱导抗原特异性的Th2反应。我们假设 注射内毒素/抗CD40激活的和转基因的DC可以 诱导抗原特异性调节性T细胞耐受，可能抑制糖尿病 糖尿病前期NOD小鼠的研究进展。此外，DC还可以直接隔离 或从个别患者的骨髓细胞中产生，激活并 体外转基因，然后返回给患者，使这成为一种 非常安全的临床程序。 这项建议的目标是：1)确定最优条件 转基因树突状细胞的产生，2)检测其治疗效果 转基因DC对糖尿病前期NOD小鼠糖尿病进展的影响，3) 确定转基因DC作用的机制(S) 糖尿病前期NOD小鼠。 这项提案的结果将解决有关 T细胞和DC在自身免疫反应中的相互作用并可能提供 预防和抑制人类免疫缺陷的新型免疫疗法的基础 IDDM。

DESCRIPTION (provided by applicant) Dendritic cells (DCs) can either sensitize naive T cells via efficiently presenting antigens, or they can tolerize T cells by inducing antigen-specific T cell anergy or regulatory responses. DCs have been largely overlooked as potential therapeutic agents for IDDM as they are not thought to be direct killers of beta-cells. Notably, LPS/anti-CD40 activated DCs express high levels of membrane-associated FasL, which can induce effector T cells to apoptose, and primed pro-inflammatory Th1 cells are particularly sensitive to FasL. Furthermore, activated DCs secrete inhibitory factors, such as TGF-beta, which can down-regulate the functions of T cells and antigen presenting cells. However, immunotherapy based on LPS/anti-CD40 activated DCs lacks antigen specificity, which may cause general immunosuppression. Gene therapy offers a powerful tool to engineer DCs to induce regulatory T cell tolerance to beta-cell antigens. Our preliminary studies have shown that LPS/anti-CD40 activated DCs, which have been transfected with a plasmid encoding a beta-cell antigen, induce antigen-specific Th2 responses in vivo. We hypothesize that administration of LPS/anti-CD40 activated and genetically modified DCs can induce antigen-specific regulatory T cell tolerance, which may inhibit diabetes progression in pre-diabetic NOD mice. In addition, DCs can be directly isolated or generated from bone marrow cells from individual patients, activated and genetically modified ex vivo, and then returned to the patient, making this a very safe clinical procedure. The goals of this proposal are to: 1) determine the optimal conditions for the generation of genetically modified DCs, 2) examine the therapeutic effect of genetically modified DCs on diabetes progression in pre-diabetic NOD mice, 3) determine the mechanism(s) underlying the action of genetically modified DCs in pre-diabetic NOD mice. The results of this proposal will address fundamental questions concerning the interaction of T cells and DCs during an autoimmune response and may provide the basis for novel immunotherapies for the prevention and inhibition of human IDDM.