Gene Transfer for Autoimmune Beta Cell Damage Prevention

快速发展的基因转移技术为人类疾病的预防和治疗提供了新的和潜在的重要策略。目前的建议应用病毒介导的基因转移，目的是改变NOD小鼠的β细胞破坏性自身免疫反应特征。提出了三种通用方法，每种方法都针对致糖尿病免疫途径中独特位点的反应。在目标1中，我们将靶向在移植到已经发展成糖尿病的NOD小鼠的胰岛移植物的剧烈破坏中观察到的反应的终末阶段。我们将确定是否可以通过使用携带编码免疫抑制或耐受性分子的基因的腺病毒载体将基因直接转移到胰岛移植物来预防移植胰岛的自身免疫破坏。为了实现这一点，我们将利用我们在腺病毒介导的基因转移到胰岛和一个大的面板腺病毒结构容易获得我们的广泛经验。在目的II中，我们将尝试通过腺病毒介导的基因转移直接到预期成为糖尿病的小鼠的胰腺来预防糖尿病前期的疾病。我们假设免疫抑制或致耐受性分子的局部表达可能会中止或逆转β细胞的破坏，即使在启动后。因此，糖尿病前期小鼠将在预期的胰岛炎发展之前或之后的时间点以及在表现出明显的糖尿病之后立即进行治疗。在目标III中，我们将进行旨在通过在胸腺个体发育期间修改T细胞库来预防疾病过程的研究。我们最近开发了一种直接基因转移到胸腺的模型，非常适合这些实验。这将使我们能够确定是否免疫调节分子如MHC II类或致糖尿病自身抗原GAD 65的主要候选者的胸腺表达将消除或下调负责自身免疫β细胞破坏的T细胞克隆。我们希望这些研究不仅会导致相关治疗策略的发展，而且会进一步加深我们对导致自身免疫性β细胞破坏的免疫紊乱序列的理解。

The rapidly evolving technology of gene transfer offers novel and potentially important strategies for the prevention and treatment of human diseases. The current proposal applies viral mediated gene transfer with the intention of altering the beta-cell destructive autoimmune response characteristic of NOD mice. Three general approaches are proposed each targeting the response at a unique site in the diabetogenic immune pathway. In Aim 1, we will target the terminal phase of the response that is observed in the vigorous destruction of islet grafts transplanted to NOD mice that have already developed diabetes. We will determine whether autoimmune destruction of transplanted islets can be prevented by direct gene transfer to islet grafts using Adenoviral vectors carrying genes encoding either immune suppressive or tolerogenic molecules. To accomplish this, we will take advantage our extensive experience with Adenovirus mediated gene transfer to pancreatic islets and a large panel of Adenoviral constructs readily available to us. In Aim II, we will attempt disease prophylaxis in the pre-diabetic period by Adenoviral mediated gene transfer directly to the pancreas of mice expected to become diabetic. We hypothesize that the local expression of immunosuppressive or tolerogenic molecules may abort or reverse beta cell destruction even after initiation. Thus pre-diabetic mice will be treated at time points either before or after the expected development of insulitis and immediately after demonstrating overt diabetes. In Aim III, we will conduct studies designed to prevent the disease process prior to its initiation through modification of the T cell repertoire during its thymic ontogeny. We have recently developed a model of direct gene transfer to the thymus that is ideally suited for these experiments. This will allow us to determine whether the thymic expression of either immunoregulatory molecules such as MHC class II, or the leading candidate for a diabetogenic autoantigen, GAD65, will eliminate or down regulate the clones of T cells responsible for autoimmune beta-cell destruction. We expect these studies will not only lead to the development of relevant therapeutic strategies, but also will further our understanding of the sequence of immunological derangements that result in autoimmune beta-cell destruction.