Gene Therapy for the Treatment of Hereditary Angioedema

 描述（由申请人提供） 遗传性血管性水肿（HAE）是一种慢性、使人衰弱和可能危及生命的常染色体显性遗传疾病，对受影响个体的生活质量有显著影响。HAE的特征在于皮肤组织、胃肠道和呼吸道的复发性、通常不可预测和可变的粘膜下水肿，并且与继发于窒息的高死亡率风险相关。超过99%的HAE病例是由血浆丝氨酸蛋白酶抑制剂C1-酯酶抑制剂（C1-INH）的功能缺陷引起的。C1-INH控制血管稳态，血浆中的低水平导致血管活性肽缓激肽的积累，从而增加血管通透性。目前批准的治疗旨在减少攻击的数量、频率和严重程度。虽然这些疗法已被证明是有效的，但依从性受到高副作用、高治疗成本、药物相互作用和药物禁忌症的限制。此外，鉴于疾病的复杂性质，个体通常需要定制的个性化治疗方案。C1-INH的低血浆功能水平是由SERPING 1基因突变引起的，因此提供人C1-INH cDNA的正确拷贝的疗法是恢复血浆中功能性C1-INH水平的有希望的方法。我们建议开发一种用于治疗HAE的实验性治疗剂，其将作为表达正常人hC 1-INH蛋白的基因治疗载体的一次性施用来递送。目的是达到持续的、长期的血浆C1-INH治疗水平，以防止血管性水肿发作，而不需要重复蛋白质给药。我们将正常的hC 1-INH cDNA序列克隆到腺相关血清型rh.10（AAVrh.10）病毒载体中以产生AAVrh.10hC1-INH载体，并设计C1-INH缺陷小鼠模型以测试治疗功效。我们提出三个具体目标：目标1。证明在胃肠外施用AAVrh.10hC1-INH后野生型小鼠体内的功能性人C1-INH蛋白水平。目标二。表征具有与HAE相似的表型的C1-INH缺陷小鼠模型。目标3。使用来自目的2的小鼠模型，证明AAVrh.10hC1-INH的单次全身施用逆转小鼠C1-INH缺乏表型并恢复C1-INH的正常功能水平。如果研究成功，AAVrh.10hC1-INH载体将在小鼠中产生高、持久水平的功能性hC 1-INH，载体剂量可扩展至安全的人类剂量。进一步的成功将通过C1-INH缺陷小鼠的正常表型来证明，其通过正常的血浆C4水平、降低的血管渗透性和粘膜下水肿来证明。该提议是编码C1-INH cDNA的AAVrh.10基因转移载体的翻译开发，使得单次施用将为HAE的治疗提供持续的长期治疗益处，从而避免重复C1-INH蛋白质施用的需要。

 DESCRIPTION (provided by applicant) Hereditary angioedema (HAE) is a chronic, debilitating and potentially life-threatening autosomal dominant disease that has a dramatic impact on the affected individual's quality of life. HAE is characterized by recurrent, often unpredictable and variable submucosal edema of cutaneous tissues, the gastrointestinal and respiratory tracts and is associated with a high mortality risk secondary to asphyxiation. More than 99% of HAE cases are caused by functional deficiency of the plasma serine protease inhibitor C1-esterase inhibitor (C1-INH). C1-INH controls vascular homeostasis and low levels in plasma leads to accumulation of the vasoactive peptide bradykinin, with consequent increase in vascular permeability. Current approved therapies are targeted at reducing the number, frequency and severity of at- tacks. While these therapies have proven effective, compliance is limited by a high side effect profile, high cost of therapy, drug interactions and medication contraindications. Further, given the complex nature of the disease, individuals often require tailored, individualized therapeutic regimens. Low plasma functional levels of C1-INH are caused by mutations on the SERPING1 gene, thus a therapy that pro- vides a correct copy of the human C1-INH cDNA is a promising approach to restore functional C1-INH levels in plasma. We propose to develop an experimental therapeutic for the treatment of HAE that will be delivered as a one-time administration of a gene therapy vector expressing the normal human hC1-INH protein. The goal is to reach sustained, long-term plasma C1-INH therapeutic levels to prevent angioedema attacks without the need of repeated protein administration. We have cloned the normal hC1-INH cDNA sequence into an adeno-associated serotype rh.10 (AAVrh.10) viral vector to generate the AAVrh.10hC1-INH vector, and designed a C1-INH deficient mouse model to test therapeutic efficacy. We propose 3 specific aims: Aim 1. Demonstrate functional human C1-INH protein levels in vivo in wild type mice after parenteral administration of AAVrh.10hC1-INH. Aim 2. Characterize a C1-INH-deficient mouse model with a phenotype similar to HAE. Aim 3. Using the mouse model from aim 2, demonstrate that a single systemic administration of AAVrh.10hC1-INH reverts the mouse C1-INH deficiency phenotype and restores normal functional levels of C1-INH. If studies are successful, AAVrh.10hC1-INH vector will produce high, long lasting levels of functional hC1-INH in mice, at vector doses that scale to a safe human dose. Further success will be demonstrated by a normal phenotype in C1-INH deficient mice, demonstrated by normal plasma C4 levels, decreased vascular permeability and submucosal edema. The proposal is the translational development of an AAVrh.10 gene transfer vector encoding C1-INH cDNA such that a single administration will provide sustained, long-term therapeutic benefit for the treatment of HAE, thus obviating the need for repeated C1-INH protein administration.