Development of tolerogenic dendritic cell-based immunotherapies and restorative insulin approaches to alleviate type 1 diabetes

总结 1型糖尿病（T1 D）的特征是由于自身免疫事件而无法达到正常血糖 错误地以破坏胰腺中产生胰岛素的β细胞为目标。T1 D的主要挑战是 双重冲击，即（1）慢性自身免疫破坏β细胞和（2）恢复是不可逆的 由于反复的慢性自身反应性发作而丧失。虽然目前的治疗方法确实可以温和地减少 由于高血糖症，它们可能无意中导致显著的健康并发症（即，全身免疫抑制）， 药物损害天然宿主免疫力并使生理功能失调， 急性/慢性排斥）。实验室的长期目标是直接解决这些挑战， 通过产生抗原特异性耐受以抑制自身免疫介导的事件来有效缓解T1 D 结合胰岛素恢复策略以减轻高血糖症。调查有两个主要的 旨在解决这一挑战：（1）工程化MHC II类修饰的致耐受性树突状细胞免疫疗法 特异性抑制β细胞区室中的自身反应性攻击，而不损害天然宿主 免疫力（对病原体或转化细胞），和（2）发展供体来源的MHC I类匹配 将β细胞接种在新型生物材料中，以恢复胰岛素产生并使血糖水平正常化。为 第一个目标， 研究将通过敲除负责耐受性的关键基因， 管辖豁免权。该方法与内源性MHC II类沉默相结合， 用编码专门呈递β细胞自身抗原肽的经修饰的MHC II类的转基因 具有高亲和力。结果将导致致耐受性DC仅呈递MHC II类限制性β细胞 自身抗原在体内过继转移后，导致受抑制的自身反应性T细胞应答， 损害正常的宿主适应性免疫。即使成功地阻止了反复的自身反应性T细胞攻击， 在T1 D的中期和晚期，组织损伤通常是不可逆的。为了应对这一挑战，第二个目标 将开发一种使用供体来源的MHC I类匹配的β细胞的恢复方法， 生物材料来恢复体内胰岛素的产生。供体来源的β细胞将被基因重编程， 表达与受体单倍型匹配的MHC I类;该方法将突出使用供体的价值。 用于修复应用的纸巾。这些产生胰岛素的供体来源的MHC I类匹配的β细胞将 然后在植入非肥胖糖尿病小鼠模型之前，将其接种在新型专利生物材料中。 该方法的成功将通过葡萄糖恢复正常血糖来抑制糖尿病的进展， 依赖胰岛素分泌。从这些研究中产生的结果将支持创新的发展， 以及用于对抗T1 D的新的转化和临床相关的治疗应用。

SUMMARY Type 1 diabetes (T1D) is characterized by an inability to achieve normoglycemia due to autoimmune events mistakenly targeting destruction of insulin-producing beta-cells of the pancreas. The major challenge of T1D is the two-fold onslaught whereby (1) chronic autoimmunity destroys beta-cells and (2) recovery is irreversibly lost due to the repeated chronic autoreactive attacks. Although current treatments do temperately reduce hyperglycemia, they can inadvertently lead to significant health complications (i.e. global immunosuppressive drugs impair natural host immunity and deregulate physiological functions and allogenic transplants are met with acute/chronic rejection). The long-term goals of the laboratory are to directly address these challenges of effectively alleviating T1D by developing antigen-specific tolerance to restrain autoimmune-mediated events coupled with insulin restorative strategies to alleviate hyperglycemia. The investigations have two principal aims to tackle this challenge: (1) engineering MHC class II-modified tolerogenic dendritic cell immunotherapies to specifically restrain autoreactive attacks in the beta-cell compartment without impairing natural host immunity (to pathogens or transformed cells), and (2) development of donor-derived MHC class I-matched beta-cells seeded in novel biomaterials to restore insulin production and normalize blood glucose levels. For the first aim, studies will reprogram DC towards tolerogenic states by knocking out key genes responsible for governing immunity. The approach is combined with silencing of endogenous MHC class II and replacing that with a transgene encoding a modified MHC class II that exclusively presents beta-cell autoantigen peptides with high affinity. Results will lead to tolerogenic DC solely presenting MHC class II-restricted beta-cell autoantigens upon adoptive transfer in vivo, leading to restrained autoreactive T cell responses without impairing normal host adaptive immunity. Even with success in stopping repeated autoreactive T cell attacks, tissue damage is often irreversible in mid- and late-stages of T1D. To address this challenge, the second aim will develop a restorative approach using donor-derived MHC class I-matched beta-cells seeded on novel biomaterials to restore insulin production in vivo. Donor-derived beta-cells will be genetically reprogrammed to express MHC class I matched to the recipient's haplotype; the approach will highlight the value in use of donor tissues for restorative applications. These insulin-producing donor-derived MHC class I-matched beta-cells will then be seeded in a novel patented biomaterial prior to implantation in the non-obese diabetic mouse model. Success of the approach will restrain diabetes progression by restoring normoglycemia through glucose- dependent insulin production. Findings generated from these studies will support development of innovative and novel translational and clinical-relevant therapeutic applications for combating T1D.