Encapsulated cells to treat type 1 diabetes

描述（由申请人提供）： 基因修饰细胞的包封允许1型糖尿病的胰岛素递送，而不需要免疫抑制。糖尿病需要严格的血糖控制，以延迟或预防晚期并发症的发生。包裹必须允许营养物质的交换以维持细胞活力，并允许胰岛素流出，但保护细胞免受免疫攻击。利用Theracyte免疫隔离装置，我们将转基因表达大鼠促红细胞生成素（EPO）的血管平滑肌细胞（VSMC）包裹起来，并将其移植到致敏受体大鼠体内。血细胞比容增加了75%，并保持高水平长达2年。重要的是，在取出Theracyte装置并植入新装置后，再次实现了持续增加的血细胞比容。因此，Theracyte设备可以维持细胞，保护同种异体细胞免受免疫攻击，并允许第二次植入。 在第一个目标中，我们建议使用封装的VSMC转导表达葡萄糖调节胰岛素治疗糖尿病大鼠。VSMC多重转导表达葡萄糖调节的胰岛素将被克隆和接种在Theracyte设备和植入糖尿病大鼠。在第二个目标中，我们将研究使用Theracyte设备植入糖尿病大鼠的转基因胰岛。糖尿病大鼠将接受用编码Bcl-2的慢病毒载体遗传修饰的同种异体大鼠胰岛接种的包封装置，以防止细胞凋亡，并与经转导以表达胰高血糖素样肽-1（GLP-1）或EPO的VSMC共接种，以延长其功能和治疗寿命。我们还将用目的1中产生的表达葡萄糖调节胰岛素的转导克隆VSMC共接种胰岛。 该建议的长期目标是（1）开发克隆的、充分表征的细胞系，其可以移植以治疗患有糖尿病的大鼠，和（2）开发允许移植同种异体胰岛以长期存活和治疗而不需要免疫抑制的方法。该方法的益处在于，仅产生一种人细胞系并表征用于治疗所有患者。这些研究将为糖尿病啮齿动物提供有价值的临床前信息，可用于治疗1型糖尿病患者。

DESCRIPTION (provided by applicant): Encapsulation of genetically modified cells permits insulin delivery for Type 1 diabetes without the need for immunosuppression. Diabetes mellitus requires tight blood glucose control to delay or prevent the onset of late complications. The encapsulation must permit the exchange of nutrients to sustain cell viability, and allow insulin to efflux, but shield cells from immune attack. Using Theracyte immunoisolation devices, we encapsulated vascular smooth muscle cells (VSMC) transduced to express rat erythropoietin (EPO) and transplanted them into allergenic recipient rats. Hematocrits increased by up to 75% and remained high for up to 2 years. Importantly, after Theracyte devices were removed and new ones implanted sustained increased hematocrits were again achieved. Thus, Theracyte devices can sustain cells, protect allogeneic cells from immune attack, and allow second implants. In the first aim we propose to use encapsulated VSMC transduced to express glucose-regulated insulin to treat diabetic rats. VSMC multiply transduced to express glucose-regulated insulin will be cloned and seeded in Theracyte devices and implanted in diabetic rats. In a second aim we will study genetically modified islets implanted in diabetic rats using Theracyte devices. Diabetic rats will receive encapsulation devices seeded with allogeneic rat islets genetically modified with lentivirus vector encoding Bcl-2 to prevent apoptosis and co-seeded with VSMC transduced to express glucagon like peptide-1 (GLP-1) or EPO to expand their function and therapeutic lifetime. We will also co-seed islets with transduced cloned VSMC expressing glucose-regulated insulin generated in aim 1. The long term goals of this proposal are (1) to develop cloned, well characterized cell lines that may be transplanted to treat rats with diabetes and (2) to develop methods to permit implantation of allogeneic islets for long term survival and therapy without the need for immunosuppression. This approach has the benefit that only one human cell line will be generated and characterized for the treatment of all patients. These studies will provide valuable preclinical information from diabetic rodents that may be applied to treat patients with type 1 diabetes.