Rapid Transient Depletion of Pre-existing Antibodies for rAAV Gene Delivery

项目概要： 该提案针对AAV介导的基因治疗的翻译中的关键挑战，即广泛存在的 人类中预先存在的αAAV抗体（Ab）。预先存在的α AAV-Ab阻止AAV载体进入， 转导靶细胞。目前，只有α AAV-Ab阴性的个体才有资格进行AAV基因治疗 治疗，因为没有有效的方法来克服这一挑战。我们最近出版的 研究表明，广泛的免疫靶向是通过免疫系统进行有效Ab耗竭所必需的。 在小鼠模型中，使用组合免疫抑制（IS），并确定了有效的IS Ab耗尽方法。 雷帕霉素和强的松龙然而，这种IS方案需要长达8-12周的每日给药。 链球菌的IgG降解酶（IdeS）是特异性切割IgG的半胱氨酸蛋白酶 分子。许多研究已经证明了IdeS在动物中的快速和有效的IgG降解， 支持IdeS的治疗潜力。IdeS具有4.9± 2.8小时的短半衰期， 显示出剂量限制性毒性。因此，我们假设IV IdeS给药可能提供一种新的 克服rAAV介导的基因治疗中预先存在的αAAV-IgG的工具。该提案旨在制定一项 用于有效翻译rAAV基因疗法以治疗疾病的新的有效ab-耗尽方法 临床，使用MPS IIIB小鼠模型，MPS IIIB是一种破坏性神经性溶酶体贮积病， 治疗目前可用。利用IdeS证明的快速有效的Ab去除， 该提案将导致开发一种有效消除预先存在的α AAV-Ab的新方法， 这可以使所有需要的患者适合于AAV基因治疗和一般的病毒基因治疗。我们 因此，我相信IdeS可以为先前存在的Abs对翻译提出的挑战提供答案 使用AAV和其他病毒载体的基因治疗产品。

Project Summary: This proposal targets a critical challenge in the translation of AAV-mediated gene therapy, the widespread pre-existing αAAV antibodies (Abs) in humans. Pre-existing αAAV-Abs block AAV vectors from entering and transducing target cells. Currently, only αAAV-Abs-negative individuals are eligible for AAV-gene therapy treatment, because no effective approach is available to overcome this challenge. Our recently published studies demonstrated that broad immune targeting is required for effective Ab-depletion by immune suppression (IS) and identified an effective IS Ab-depletion approach in a mouse model, using combination of rapamycin and prednisolone. However, this IS regimen requires up to 8-12-week-long daily administration. The IgG degrading enzymes of Streptococci (IdeS) are cysteine proteases that specifically cleaves IgG molecules. Numerous studies have demonstrated rapid and effective IgG degradation by IdeS in animals and in humans, supporting the therapeutic potential of IdeS. IdeS has a short half-life of 4.9±2.8hr with no demonstrated dose limiting toxicity. We therefore hypothesize that IV IdeS administration may offer a novel tool to overcome the pre-existing αAAV-IgG for rAAV-mediated gene therapy. This proposal is to develop a novel effective ab-depletion approach for the effective translation of rAAV gene therapy to treat diseases in clinic, using a mouse model of MPS IIIB, a devastating neuropathic lysosomal storage disease, for which not treatment is currently available. Taking advantage of demonstrated rapid effective Ab removal by IdeS, this proposal will lead to the development of a novel approach for effective depletion of pre-existing αAAV-Abs, which may make all patients in need eligible to AAV gene therapy, and viral gene therapy in general. We therefore believe that IdeS may offer the answer to the challenge posed by pre-existing Abs to the translation of gene therapy products using AAV and other viral vectors.