Gene transfer with A20 to improve islet transplantation

描述(由申请人提供)：胰岛细胞移植治疗I型自身免疫性糖尿病患者具有治愈糖尿病和预防其衰弱并发症的潜力。胰岛移植领域的重大障碍减缓了其临床应用数十年。最近在加拿大埃德蒙顿成功进行了第一系列胰岛移植的突破，重新确立了朗格汉斯胰岛移植作为治愈I型糖尿病的一种可行的治疗选择。这种疗法的临床适用性和广泛应用受到两个主要障碍的阻碍：(I)需要大量来自至少两个胰腺的胰岛才能达到正常血糖，以及(Ii)需要强化免疫抑制，而这不能用于儿科人群。 胰岛移植失败的原因是多因素的，包括：(1)原发无功能；(2)同种异体排斥反应；(3)自身免疫复发。不管是什么原因，胰岛最终都会被细胞凋亡所破坏。致力于设计能够抵抗免疫和非免疫损伤的“不畏死亡”的胰岛的努力，可能会通过减少所需的胰岛数量并允许使用较温和的免疫抑制来提供解决方案。我们的工作重点是确定胰岛基因工程的“保护性”候选者。 我们的初步数据显示，A20是胰岛对损伤的生理反应的一部分。A20在胰岛的表达可保护细胞因子和Fas/FasL介导的细胞凋亡，并通过阻断核因子-β发挥强大的抗炎作用。我们已经证明，A20在胰岛的过表达克服了移植成功所面临的第一个障碍，即原发无功能。 我们的目标是确定携带细胞保护基因A20的基因工程是否能保护胰岛免受同种异体移植排斥反应(C57BL/6到糖尿病BALB/c)和反复自身免疫(NOD-SCID到糖尿病NOD)的保护。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接受者(将C57BL/6移植到糖尿病NOD)。基因转移将使用两种重组腺病毒(Rad.)和重组相关腺病毒(RAAV)，这两种病毒都被证明可以有效地转导胰岛，而不会产生重大毒性或功能损害。 我们认为，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的侮辱。这将克服对大量胰岛的需求和对密集免疫抑制的需要。有益的结果将为临床前(灵长类)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.