Engineering dendritic cells to target islet antigen to pro-tolerogenic subsets for prevention and treatment of Type 1 Diabetes

项目摘要 尽管通过将这些抗原靶向于树突状细胞(DC)来诱导抗原特异性耐受 在多项临床前研究中已有报道，目前还没有有效的方法在临床上使用DC 预防或逆转自身免疫力。DCs已被证明本质上具有恢复和 保持免疫耐受性，使其成为治疗自身免疫性疾病的极具吸引力的候选药物。 然而，只有非激活的DC(天生具有耐受/抑制表型)才能诱导 耐受性，而激活的DC可以触发免疫。值得注意的是，没有能够传递抗原的策略。 对于未激活的DC来说是唯一的。为了克服这一限制，该提案的长期目标是设计 DC将确保仅通过耐受性亚群呈递胰岛衍生抗原用于治疗1型糖尿病 (T1D)。中心假设是，通过确保胰岛来源的抗原是由耐受性 这些DC将导致胰岛特异性自身反应性T细胞的消除和保护性树突状细胞的诱导。 这项提案的总体目标将通过追求以下两个具体目标来检验：(1)工程学 树突状细胞表达胰岛来源抗原使用电路限制表达促耐受树突状细胞和(2) 工程树突状细胞人为地增强亲耐受不可逆表型，同时还推动 胰岛来源的抗原。对于目标1，包含新启动子的构建体驱动产生耐受的DC在 与基于microRNA的电路相结合，防止炎症反应中的抗原表达将是 测试是否有耐受性。对于Aim 2，一种转录因子可以强制DC进入高度亲- 耐受状态将用于编码胰岛衍生抗原的构建，以在T1D小鼠中设计DC 模特们。这种转录调节因子在肿瘤内树突状细胞中被发现，其强制激活被发现 将DC塑造为免疫抑制状态，即使在应对强烈炎症时也无法恢复 刺激物。拟议的研究具有创新性，因为它首次尝试设计DC以确保 胰岛来源的抗原只能由支持耐受的细胞提呈。这项提议的意义在于，如果 成功后，它将确定一种安全地设计DC以诱导耐受的战略，并将提供 强大的科学框架，用于进一步的研究，以设计这些免疫的关键协调者 系统。归根结底，从这项工作中获得的知识有可能为创新奠定基础 以工程为基础的疗法，以阻止T1D的自身免疫，这是实现治愈的关键步骤。

Project Summary Although induction of antigen-specific tolerance by means of targeting such antigens to dendritic cells (DCs) has been reported in multiple pre-clinical studies, there are currently no effective approaches using DCs in the clinic to prevent or reverse autoimmunity. DCs have been proven to intrinsically possess the ability to restore and maintain immune tolerance, making them very attractive candidates for treatment of autoimmune diseases. However, only non-activated DCs (which inherently possess a tolerogenic/suppressive phenotype) can induce tolerance, whereas activated DCs can trigger immunity. Notably, there is no strategy able to deliver antigen uniquely to non-activated DCs. To overcome this limitation, the long-term goal of this proposal is to engineer DCs to guarantee presentation of islet-derived antigen solely by tolerogenic subsets to treat Type 1 Diabetes (T1D). The central hypothesis is that by ensuring that islet-derived antigen is presented exclusively by tolerogenic DCs, these DCs will lead to elimination of islet-specific auto-reactive T cells and induction of protective Tregs. The overarching goal of this proposal will be tested by pursuing the following two specific aims: (1) Engineering DCs to express islet-derived antigen using circuits that limit expression to pro-tolerogenic DCs and (2) Engineering DCs to artificially enforce a pro-tolerogenic irreversible phenotype while also driving expression of islet-derived antigen. For Aim 1, constructs containing a new promoter driving expression to tolerogenic DCs in combination with microRNA-based circuits that prevent antigen expression in response to inflammation will be tested for induction of tolerance. For Aim 2, a transcription factor that can enforce DCs into a highly pro- tolerogenic state will be used in a construct encoding islet-derived antigen to engineer DCs in T1D mouse models. This transcriptional regulator was identified in intra-tumor DCs, and its enforced activation was found to shape DCs into an immune suppressive state that could not be reverted even in response to strong inflammatory stimuli. The proposed research is innovative because it attempts for the first time to engineer DCs to ensure presentation of islet-derived antigen only by pro-tolerogenic cells. The significance of this proposal is that, if successful, it will have identified a strategy to safely engineer DCs for induction of tolerance and will provide a strong scientific framework for further investigations to engineer these critical orchestrators of the immune system. Ultimately, the knowledge derived from this work has the potential to lay the ground for innovative engineering-based therapies to stop autoimmunity in T1D, which constitutes an essential step to achieve a cure.