Models and Gene Therapies for AAT Deficiency

项目概要（总体） Alpha-1 抗胰蛋白酶缺乏症 (AATD) 是由 SERPINA1 基因突变引起的。的 E342K (PI*Z) 突变等位基因在欧洲血统中非常常见，并且 E342K 纯合子编码的蛋白质分泌受损，导致 AAT 血清水平不足。 由于 AAT 通常会保护肺部的弹性蛋白免遭降解，因此有效 AAT 触发因素的丧失 肺部炎症、气道阻塞和肺气肿是限制生命的主要因素 AATD 的表现。本提案中的项目力求追求众多并行 开发 AATD 基因疗法的策略。大多数这些策略都围绕着使用 基于重组腺相关病毒 (rAAV) 的载体，这是一种平台技术， 在治疗其他遗传病方面也取得了非常成功的成果。在项目1中，优化的rAAV载体将是 在基因定义的动物模型（包括小鼠和雪貂）中进行研究，并与 使用受监管的条件转基因系统进行转基因重建研究以进行比较 两个相关的潜在目标替代水平（11μM 和 25μM）且具有临床相关性 将研究终点。在项目 2 中，新的 CRISPR 变体将用于基因编辑， 治疗 AATD 的碱基编辑和主要编辑策略。在项目3中，我们将自然筛选 从中国西部偏远人群中获得的 AAV 衣壳文库用于鉴定 衣壳增强了 AATD 基因治疗的功效和安全性。最后，在项目 4 中，我们将 使用新型 Treg 和 CAR-Treg 策略选择性调节抗载体免疫反应。 还将有两个核心。 Core A会为每个项目提供重要的Vector 免疫学检测，可以识别宿主对 AAV 免疫反应造成的限制 衣壳、AAT 转基因或 Cas9 衍生蛋白。核心B将提供动物模型和 动物模型中的生理测量，用于测试优化的 rAAV 载体、基因 编辑工具和免疫调节方法。计划调查员有以下记录 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.