Development of a safer stem cell-based diabetes therapy via suicide gene-mediated ablation of proliferative cells

项目摘要/摘要 糖尿病是世界范围内一个日益重要的健康问题。在胰岛素被发现后的100年里， 在糖尿病患者的护理方面取得了巨大的进步，包括长效胰岛素制剂， 胰岛素泵、连续血糖监测仪和多种影响胰岛素的药物 分泌物和敏感性。尽管取得了所有这些进展，但大多数糖尿病患者目前无法实现 建议的血糖控制目标。虽然糖尿病患者移植供体来源 由于来源材料有限，胰岛或完整的胰腺仍然是一种罕见的手术，这些细胞为基础 治疗在恢复血糖控制方面非常有效。为了让基于细胞的疗法 为更多的患者提供糖尿病，再生医疗解决方案(RMS)开发了一种专有协议 为了将诱导多能干细胞(IPSC)--一种几乎无限的细胞来源--转化为胰岛样簇 包括产生胰岛素的类β细胞的细胞。这些细胞表现出类似于初级测试版的功能 在体外和移植到糖尿病小鼠后的细胞，表明它们作为基于细胞的治疗的潜力 治疗糖尿病。然而，就像所有基于IPSC的疗法一样，安全性问题仍然存在：即使是移植一种 在基于iPSC的产品中，少量的增殖细胞可能会导致不希望看到的突起或肿瘤 在移植物部位形成。为了解决这一潜在风险，植入式治疗公司开发了一种新的基因 改良的IPSC系FailSafeTM，其中胸苷激酶基因纯合整合在 重要的细胞周期调控基因CDK1。FDA批准的药物治疗FailSafeTM细胞 因此，更昔洛韦可以选择性地消除活跃的增殖细胞。在这个项目中，我们将结合 FailSafeTM iPSC和RMS的专有协议用于生产类胰岛状细胞群的演示 联合产品的潜力，以产生一种更安全的基于细胞的糖尿病疗法。首先，我们将定义 从培养中的胰岛样团中去除增殖细胞的最佳条件。接下来，我们将演示 治疗的FailSafeTM集群在糖尿病小鼠模型中的安全性和有效性。加在一起，这些 实验将为开发一种基于细胞的糖尿病治疗方法奠定基础， 与竞争产品相比的安全状况。

Project Summary/Abstract Diabetes is an increasingly important health problem worldwide. In the 100 years since the discovery of insulin, tremendous advances have been made in the care of diabetic patients, including long-acting insulin formulations, insulin pumps, continuous glucose monitors, and wide array of pharmacologic agents that influence insulin secretion and sensitivity. Despite all of these advances, a majority of diabetic patients cannot achieve currently recommended targets for blood glucose control. Although transplantation of diabetic patients with donor-derived pancreatic islets or intact pancreas remains a rare procedure due to limited source material, these cell-based therapies are extremely effective in restoring blood glucose control. In order to make a cell-based therapy for diabetes available to more patients, Regenerative Medical Solutions (RMS) has developed a proprietary protocol for converting induced pluripotent stem cells (iPSC), a virtually unlimited cell source, into islet-like clusters of cells that include insulin-producing beta-like cells. These cells demonstrate functionality similar to primary beta cells both in vitro and after transplantation into diabetic mice, indicating their potential as a cell-based therapy for diabetes. However, as will all iPSC-based therapies, safety concerns remain: the transplantation of even a small number of proliferative cells in an iPSC-based product may result in undesired outgrowths or tumor formation at the graft site. To address this potential risk, Implant Therapeutics has developed a novel genetically modified iPSC line, FailSafeTM, in which the thymidine kinase gene is homozygously integrated downstream of the essential cell cycle regulatory gene CDK1. Treatment of FailSafeTM cells with the FDA-approved drug ganciclovir thus leads to selective elimination of actively proliferating cells. In this project, we will combine FailSafeTM iPSC and RMS’s proprietary protocol for the production of islet-like clusters of cells to demonstrate the potential of the combined product to produce a safer cell-based therapy for diabetes. First, we will define optimal conditions for the ablation of proliferating cells from islet-like clusters in culture. Next, we will demonstrate the safety and efficacy of the treated FailSafeTM clusters in a mouse model of diabetes. Together, these experiments will lay the foundation for the development of a cell-based therapy for diabetes with an improved safety profile compared to competing products.