Engineering and targeting novel antigen-specific tolerogenic interfaces

 描述（申请人提供）：自身免疫性疾病是免疫耐受性受损的结果，动物研究表明永久恢复抗原特异性耐受性可以构成治愈方法。然而，在人类中实现这一目标非常具有挑战性，因为他们在遗传和环境构成方面具有高度异质性，并且疾病是多因素的。与此同时，这些疾病的发病率正在上升。这种异质性可以通过靶向耐受诱导的多个生物学途径来克服，特别是在疾病驱动的自反应性T细胞中，并且可能在战略组织部位内。药物、生物制剂和/或耐受性抗原的各种组合已在治疗中进行了测试，但在这种情况下，每种组分都独立起作用。缺少的是单个“致耐受性界面”，其使得抗原性和多种致耐受性信号能够一起并伴随地作用于靶T细胞，导致最佳信号整合，并最终导致这些自身反应性T细胞的最佳重编程。临床上最有益的结果是重编程为抗原特异性调节性T细胞（TCLs），其寿命长，并具有通过抑制对其他疾病相关抗原的自身免疫反应（感染性耐受）来维持耐受性的能力。树突状细胞（DC），已经在各种人类疾病的治疗中进行了测试，是最通用的抗原呈递细胞之一，可以为此目的进行操作。然而，尚未实现由相关抗原和致耐受性信号的最佳组合组成的定制和复杂界面的创建。有了这个探索/开发资助，我们建议设计新的基于DC的致耐受性界面，其组分通过电穿孔作为mRNA的混合物递送。在特定目标1下，我们将测试该系统中几种抗原和致耐受性产物的表达，并鉴定可以最有效地将致糖尿病T细胞重编程为THBG的组合。主要目标是找到在诱导高功能和稳定的Tcl 3中协同作用的信号传导途径，并在体内产生能够介导长期保护免受疾病的Tcl 3。在特异性目标2下，我们将使用相同的基于mRNA的操作方法在DC中过表达特异性归巢受体。目标是增强致耐受性DC向胰腺淋巴结（致糖尿病性T细胞在此被引发）或胰岛（致耐受性DC在此发挥其致病功能）的迁移。基于DC的细胞疗法已经越来越多地在临床试验中进行测试，以治疗人类疾病，主要是癌症，最近用于自身免疫。这些研究表明，DC没有迄今为止测试的许多药物和生物制剂的不良反应。致耐受性DC的开发（1）靶向特异性T细胞，（2）通过多种生物学途径使其有效重编程为T细胞，和（3）在相关组织中更好地和优先地积累，将极大地改善基于细胞的治疗自身免疫性疾病的功效和安全性。

 DESCRIPTION (provided by applicant): Autoimmune diseases are the result of impaired immune tolerance and animal studies indicate that restoring antigen-specific tolerance permanently can constitute a cure. However, this is very challenging to achieve in humans, because they are highly heterogeneous in their genetic and environmental makeup, and the diseases multifactorial. Meanwhile, the incidence of these diseases is on the rise. This heterogeneity may be overcome by targeting multiple biological pathways of tolerance induction, specifically in disease-driving self-reactive T cells, and possibly within strategic tissue sites. Various combinations of drugs, biologics and/or tolerizing antigens have been tested in therapy, but each component acts independently in this case. What is missing is a single "tolerogenic interface" that enables the antigenic and multiple tolerogenic signals to act together and concomitantly on target T cells, resulting in optimal signal integration, and ultimately, optimal reprograming of these self-reactive T cells. The most clinically beneficial outcome is the reprograming into antigen-specific regulatory T cells (Tregs), which are long-lived and have the ability to perpetuate tolerance by suppressing autoimmune responses to other disease-relevant antigens (infectious tolerance). Dendritic cells (DCs), already tested in the treatment of a variet of human diseases, are among the most versatile antigen-presenting cells that can be manipulated for this purpose. However, the creation of customized and complex interfaces consisting of relevant antigens and optimal combinations of tolerogenic signals has not yet been achieved. With this Exploratory/Developmental grant, we propose to engineer new DC-based tolerogenic interfaces whose components are delivered as mixtures of mRNA by electroporation. Under Specific Aim 1, we will test the expression of several antigens and tolerogenic products in this system, and identify combinations that can most efficiently reprogram diabetogenic T cells into Tregs. The major goals are to find signaling pathways that synergize in inducing highly functional and stable Tregs, and to generate Tregs in vivo that are capable of mediating long-lasting protection from disease. Under Specific Aim 2, we will use the same mRNA-based manipulation approach to overexpress specific homing receptors in DCs. The goal is to enhance the migration of tolerogenic DCs to the pancreatic lymph nodes, where diabetogenic T cells are primed, or to the pancreatic islets, where they exert their pathogenic function. DC-based cell therapies have been increasingly tested in clinical trials to treat human disease, mostly cancer, and more recently for autoimmunity. These studies suggest that DCs are devoid of the adverse effects of many drugs and biologics tested to date. The development of tolerogenic DCs that (1) target specific T cells, (2) engage them through multiple biological pathways for efficient reprograming into Tregs and (3) accumulate better and preferentially in relevant tissues will greatly improve both efficacy and safety of cell-based therapies for autoimmune diseases.