Models and Gene Therapies for AAT Deficiency

项目总结(总体) α-1抗胰蛋白酶缺乏症(AATD)是由SERPINA1基因突变引起的。这个 E342K(Pi*Z)突变等位基因在欧洲血统中非常常见，E342K 纯合子编码一种分泌受损的蛋白质，导致血清AAT水平不足。 由于AAT通常保护肺中的弹性蛋白不被降解，有效AAT的丧失触发了 肺部炎症、呼吸道阻塞和肺气肿，这是主要的生命限制因素 AATD的表现。这项提案中的项目寻求进行许多平行的 开发AATD基因治疗的策略。这些策略中的大多数都围绕着使用 基于重组腺相关病毒(RAAV)的载体，这是一种具有 对其他遗传病的治疗非常成功。在项目1中，优化的rAAV载体将 在基因定义的动物模型(包括老鼠和雪貂)中进行研究，并与 利用受调控的条件转基因系统进行转基因重建的研究 两个相关的潜在目标替代水平(11微米和25微米)和临床相关 将对终端进行研究。在项目2中，新的CRISPR变体将用于基因编辑， 基础编辑和主要编辑策略，以治疗AATD。在项目3中，我们将自然而然地放映 中国西部偏远地区人群甲型肝炎病毒衣壳文库的鉴定 用于AATD基因治疗的衣壳蛋白具有增强的有效性和安全性。最后，在项目4中，我们将 使用新的Treg和CAR-Treg策略来选择性地调节抗媒介免疫反应。 还将有两个核心。核心A将为每个项目提供重要的载体 免疫学检测，可以识别由于宿主对AAV的免疫反应而产生的限制 衣壳蛋白、AAT转基因或转Cas9衍生蛋白。核心B将提供动物模型和 用于检测优化的rAAV载体基因的动物模型中的生理测量 编辑工具和免疫调节方法。项目调查人员有如下记录： 我们预计未来几年将继续进行互动和合作。

Project Summary (OVERALL) Alpha-1 antitrypsin deficiency (AATD) is caused by mutations in the SERPINA1 gene. The E342K (PI*Z) mutant allele is very common among those of European ancestry, and E342K homozygotes encode a protein with impaired secretion, resulting in deficient AAT serum levels. Since AAT normally protects elastin in the lung from degradation, loss of effective AAT triggers lung inflammation, airways obstruction and emphysema, which is the primary life-limiting manifestation of AATD. The projects within this proposal seek to pursue numerous parallel strategies to develop a gene therapy for AATD. Most of these strategies revolve around the use of recombinant adeno-associated virus (rAAV)-based vectors, a platform technology that has been very successful for other genetic diseases. In Project 1, optimized rAAV vectors will be studied in genetically defined animal models (including mice and ferrets) in comparison with transgenic reconstitution studies using a regulated conditional transgenic system to compare two relevant potential target replacement levels (11µM and 25µM) and clinically relevant endpoints will be studied. In Project 2, novel CRISPR variants will be used for gene editing, base editing and prime editing strategies to treat AATD. In Project 3, we will screen naturally occurring AAV capsid libraries obtained from remote populations in Western China to identify capsids with enhanced efficacy and safety for AATD gene therapy. Finally, in project 4, we will use novel Treg and CAR-Treg strategies to selectively modulate anti-vector immune responses. There will also be two cores. Core A will provide each project with important Vector Immunology assays, which can identify limitations due to host immune responses to AAV capsids, the AAT transgene or to Cas9-derived proteins. Core B will provide animal models and physiologic measurements in the animal models for testing of optimized rAAV vectors, gene editing tools and immune modulation approaches. Program investigators have a track record of interactions and collaborations that we anticipate will continue in future years.