Mitigating the Immunogenicity of Engineered Aav Gene Delivery Vectors by Biomaterial-Driven Immunosuppression

降低AAV基因工程载体的免疫原性 通过生物材料驱动的免疫抑制 项目总结 重组腺相关病毒(AAV)载体介导的基因传递有望在 各种慢性和遗传性疾病。尽管到目前为止临床结果巨大，但AAV载体基因 由于其耐用性，交付一直受到限制。单一AAV管理可以持续几个月到几个月 多年的基因表达高于治疗水平。然而，许多遗传性疾病需要终生 避免不可逆转的组织损伤的治疗。因此，重新管理AAV的能力对于 随着时间的推移实现持续的治疗效果。尽管AAVs被认为免疫原性低 与其他病毒载体相比，衣壳蛋白的免疫原性仍然是一个主要的 AAV媒介重新管理的障碍。 为了应对这些挑战，我们采用了内源性免疫耐受结构， 从天然磷脂酰丝氨酸脂中提取的磷酸丝氨酸(PS)，作为一种免疫抑制部分，使 AAV载体的重新管理。避免因内源性药物引起的药效损失或短循环。 自然PS结构的负电荷，我们建议将PS结构工程成定义良好的 具有全两性离子/中性电荷和高PS的免疫抑制可降解PS多肽材料 密度，并将其与AAV衣壳结合，从而使修改后的基因载体能够重新给药 能力。两个具体目标是：(A)含PS的两性离子的制备和表征 多肽修饰的AAVs；(B)体内免疫耐受和基因递送的多剂量研究 和修复缺陷小鼠。 这项拟议的工作将开发一种生物材料驱动的、启用免疫抑制的两性离子 基于PS多肽的病毒载体工程平台，实现了AAV载体的二次给药 维持它们的转导效率。对该项目的支持将启动一个 AAV介导的基因传递领域的可翻译生物材料技术。这件事的成功 该项目将推进目前以AAV为基础的基因治疗，并为患者提供临床益处。

Mitigating the immunogenicity of engineered AAV gene delivery vectors by biomaterial-driven immunosuppression PROJECT SUMMARY Recombinant adeno-associated virus (AAV) vector-mediated gene delivery is promising for a variety of chronic and genetic diseases. Despite huge clinical outcomes to date, AAV vector gene delivery has been limited due to its durability. Single AAV administration can last from months to several years of gene expression above therapeutic levels. However, many inherited diseases require lifelong treatment to avoid irreversible tissue damage. Thus, the ability to re-administer AAV is crucial to achieving sustained therapeutic efficacy over time. Although AAVs are considered low immunogenic and safe as compared with other viral vectors, the immunogenicity of capsids still represents a major obstacle to the re-administration of AAV vectors. To address these challenges, we adopt an endogenous immune tolerant structure, phosphoserine (PS) from natural phosphatidylserine lipid, as an immunosuppressive moiety to enable the re-administration of AAV vectors. To avoid efficacy loss or short circulation due to the intrinsic negative charge of native PS structure, we propose to engineer the PS structure into a well-defined immunosuppressive degradable PS peptide material with overall zwitterion/neutral charge and high PS density and conjugate it to AAV capsids, thus enabling the modified gene vectors with re-administration capability. Two Specific Aims are (a) preparation and characterization of PS-containing zwitterionic peptide-modified AAVs; (b) in vivo immune tolerance and multi-dose study of gene delivery in normal and FIX-deficient mice. The proposed work will develop a biomaterial-driven, immunosuppression-enabling, zwitterionic PS peptide-based viral vector engineering platform, realizing the re-administration of AAV vectors while maintaining their transduction efficiency. Support of this project will initiate the development of a translatable biomaterial technology for the field of AAV-mediated gene delivery. The success of this project will advance the current AAV-based gene therapy and provide clinical benefits to patients.