Gene transfer with A20 to improve islet transplantation

描述（由申请人提供）：I型自身免疫性糖尿病患者的胰岛细胞移植有可能治愈糖尿病并防止其衰弱并发症。胰岛移植领域的实质性障碍使其临床实施放缓了数十年。最近在加拿大埃德蒙顿进行的第一系列成功的胰岛移植的突破重新确立了胰岛移植作为治愈I型糖尿病的可行的治疗选择。这种疗法的临床适用性和广泛使用受到两个主要障碍的阻碍：（i）需要来自至少两个胰腺的大量胰岛以实现正常生长，和（ii）需要不能给予儿科群体的强化免疫抑制。 胰岛移植失败的原因是多方面的，包括（i）原发性无功能，（ii）同种异体移植排斥反应和（iii）自身免疫复发。不管原因如何，胰岛最终被细胞凋亡破坏。致力于工程化能够抵抗免疫和非免疫损伤的“抗死亡”胰岛的努力可能通过减少所需的胰岛数量和允许使用更温和的免疫抑制来提供解决方案。我们的工作重点是确定“保护”候选人的基因工程的胰岛。 我们的初步数据表明，A20是胰岛对损伤的生理反应的一部分。A20在胰岛中的表达保护细胞因子和Fas/FasL介导的凋亡，并通过阻断NF-κ B发挥有效的抗炎作用。B。我们已经表明，胰岛中A20的过表达克服了成功移植面临的第一个障碍，即原发性无功能。 我们的目的是确定是否与细胞保护基因A20的基因工程，将保护胰岛从同种异体移植排斥（C57 BL/6糖尿病BALB/c）和复发性自身免疫（NOD-scid糖尿病NOD）。最后，我们将确定A20是否能够成功地将同种异体胰岛移植到自身免疫受体中（C57 BL/6移植到糖尿病NOD中）。将使用两种重组腺病毒（rAd.）和重组相关腺病毒（rAAV），它们都显示出有效地转染胰岛而没有大的毒性或功能损害。 我们相信细胞保护基因A20的过表达将保护胰岛免受同种异体和自身免疫性损伤。这将克服对大量胰岛的需要和对强化免疫抑制的需要。有益的结果将为临床前（灵长类动物）和临床应用铺平道路。

DESCRIPTION (provided by applicant): Islet cell transplantation for patients with type I autoimmune diabetes has the potential to cure diabetes and protect against its debilitating complications. Substantial obstacles in the field of islet transplantation slowed its clinical implementation for decades. The recent breakthrough with the first series of successful islet transplantation in Edmonton Canada reestablished transplantation of islets of Langerhans as a viable therapeutic option for the cure of type I diabetes. The clinical applicability and wide spread use of this therapy is hampered by two major obstacles:(i) the requirement for a high number of islets derived from at least two pancreata to achieve euglycemia, and (ii) the need for intensive immunosuppression that cannot be given to the pediatric population. The causes underlying the failure of islet transplantation are multifactorial including (i) primary non-function, (ii) allograft rejection and (iii) recurrence of autoimmunity. Regardless of the cause, islets are ultimately destroyed by apoptosis. Efforts directed at engineering "death-defying" islets able to resist immune and non-immune injuries may offer a solution by reducing the number of islets required and allowing the use of milder immunosuppression. Our work is focused on defining "protective" candidates for the genetic engineering of islets. Our preliminary data reveals that A20 is part of the physiological response of islets to injury. Expression of A20 in islets protects from cytokine and Fas/FasL mediated apoptosis and exerts a potent anti-inflammatory effect via blockade of NF-?B. We have already shown that overexpression of A20 in islets overcomes the first hurdle facing successful transplantation namely, primary non-function. We aim to determine whether genetic engineering with the cytoprotective gene A20, will protect islets from allograft rejection (C57BL/6 to diabetic BALB/c) and recurrent autoimmunity (NOD-scid to diabetic NOD). Finally, we will determine whether A20 will enable successful transplantation of allogeneic islets into autoimmune recipients (C57BL/6 into diabetic NOD). Gene transfer will be performed using both recombinant adenoviruses (rAd.) and recombinant associated adenoviruses (rAAV) that have both been shown to efficiently transduce islets without major toxicity or impairment of function. It is our belief that overexpression of the cytoprotective gene A20 will protect islets from the allo and autoimmune insults. This will overcome the requirement for high numbers of islets and the need for intensive immunosuppression. Beneficial results would pave the way for pre-clinical (primates) and clinical applications.