Immunoengineered nanotechnology for targeted expansion of regulatory T cells

项目总结/摘要 开发免疫工程技术以选择性刺激和扩增调节性T（TReg）细胞 将是自身免疫性疾病治疗和移植医学的变革。广泛 已有证据表明过继转移的TReg细胞，特别是抗原特异性TReg细胞， 有效地抑制致病性自身免疫活性以对抗疾病。然而，物流和制造业 与离体扩增的T细胞相关的并发症以及安全性问题阻碍了 这种方法。因此，存在对现成的非蜂窝平台的未满足的医疗需求，所述非蜂窝平台激活 抗原特异性TReg细胞直接在患者中表现出免疫抑制。白细胞介素-2（IL-2）细胞因子 有效地激活TReg细胞，并且已被证明是过继性TReg细胞转移的有希望的替代方案。然而，在这方面， IL-2同时刺激效应细胞的活化，导致有害的脱靶效应和毒性。共- 施用与某些抗细胞因子抗体复合的IL-2优先激活和扩增TReg 但对细胞因子/抗体复合物解离的担忧阻碍了治疗， 发展这种方法。此外，IL-2处理诱导TReg细胞的非特异性扩增， 有限富集治疗上优良的上级抗原特异性细胞。 该提案旨在开发一种强大且通用的平台， 并同时抑制致病性自身反应性T细胞的功能。这项技术综合，为 第一次，三种设计方法：（1）选择性递送IL-2至TReg细胞;（2）刺激抗原特异性的TReg细胞。 使用人工抗原呈递细胞（aAPC）的TReg细胞;和（3）免疫抑制剂的局部释放 防止效应T细胞激活的药物。表示为TolAPC的新型平台包括涂覆有纳米颗粒的纳米颗粒。 与自身肽负载的主要组织相容性复合体（MHC）以及稳定的单链融合形式 选择性促进TReg扩增的IL-2/抗体复合物。这些粒子也被设计成 免疫抑制药物雷帕霉素的控制释放。将在体外和体内表征TolAPC 以评估可抑制致病性自身反应性效应T细胞的TReg细胞的选择性扩增。他们将 也可以在小鼠的自身免疫性疾病研究中进行治疗评估。作为一个模型系统，TolAPC活动 将在1型糖尿病（T1 D）中进行评估，这是一种慢性自身免疫性疾病，对全球健康的威胁越来越大 发病率以每年3%的惊人速度上升。TolAPC平台的模块化将允许 准备扩展到自身免疫性疾病治疗和移植耐受的许多应用， 抗原特异性的替代。总的来说，我们有针对性的免疫调节纳米技术将作为一种 这是一个强大而通用的工具，用于偏置免疫激活以实现治疗相关结果。

PROJECT SUMMARY/ABSTRACT Development of an immunoengineered technology to selectively stimulate and expand regulatory T (TReg) cells in vivo would be transformative for autoimmune disease treatment and transplantation medicine. Extensive evidence has established that adoptively transferred TReg cells, and in particular antigen-specific TReg cells, effectively suppress pathogenic autoimmune activity to combat disease. However, logistical and manufacturing complications as well as safety concerns associated with ex vivo expanded T cells impede clinical adoption of this approach. Thus, there is an unmet medical need for an off-the-shelf, non-cellular platform that activates antigen-specific TReg cells to manifest immunosuppression directly in patients. The interleukin-2 (IL-2) cytokine potently activates TReg cells, and has proven to be a promising alternative to adoptive TReg cell transfer. However, IL-2 concurrently stimulates activation of effector cells, resulting in harmful off-target effects and toxicities. Co- administration of IL-2 in complex with certain anti-cytokine antibodies preferentially activates and expands TReg over effector cells, but concerns about cytokine/antibody complex dissociation hinder the therapeutic development of this approach. Furthermore, IL-2 treatment induces non-specific expansion of TReg cells, with limited enrichment of therapeutically superior antigen-specific cells. This proposal aims to develop a robust and versatile platform that activates antigen-specific TReg cells and simultaneously inhibits the function of pathogenic autoreactive T cells. This technology synthesizes, for the first time, three design approaches: (1) Selective delivery of IL-2 to TReg cells; (2) Stimulation of antigen-specific TReg cells using artificial antigen-presenting cells (aAPCs); and (3) Localized release of an immunosuppressive drug to prevent effector T cell activation. The novel platform, denoted TolAPC, comprises nanoparticles coated with self peptide-loaded major histocompatibility complex (MHC) as well as a stabilized single-chain fusion format of an IL-2/antibody complex that selectively promotes TReg expansion. These particles are also engineered for controlled release of the immunosuppressive drug rapamycin. TolAPCs will be characterized in vitro and in vivo to assess selective expansion of TReg cells that can suppress pathogenic self-reactive effector T cells. They will also be therapeutically evaluated in autoimmune disease studies in mice. As a model system, TolAPC activity will be assessed in type 1 diabetes (T1D), a chronic autoimmune disease that is a growing threat to global health with incidence rising at an alarming rate of 3% annually. The modularity of the TolAPC platform will allow for ready extension to a host of applications in autoimmune disease treatment and transplant tolerance through substitution of the antigen specificity. Overall, our targeted immunomodulatory nanotechnology will serve as a powerful and general tool for biasing immune activation to effect therapeutically relevant outcomes.