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、衰弱和潜在威胁生命的常染色体显性疾病，对患者的生活质量有重大影响。HAE的特征是皮肤组织、胃肠道和呼吸道反复出现、经常不可预测和可变的粘膜下水肿，并与继发于窒息的高死亡风险相关。99%以上的HAE病例是由于血浆丝氨酸蛋白酶抑制物C_1-酯酶抑制物(C_1-INH)功能缺陷所致。氯化异烟肼控制血管内稳态，低水平的血浆导致血管活性多肽缓激肽的积聚，从而增加血管通透性。目前批准的治疗方法旨在减少AIT的数量、频率和严重程度。虽然这些疗法已被证明有效，但副作用大、治疗成本高、药物相互作用和药物禁忌症限制了依从性。此外，鉴于疾病的复杂性质，个人往往需要量身定做的个性化治疗方案。由于SERPING1基因突变导致血浆中c1-INH功能水平低下，因此，提供人类c1-INH基因正确拷贝的治疗方法是恢复血浆中c1-INH功能水平的一种有前途的方法。我们建议开发一种治疗HAE的实验性疗法，该疗法将作为表达正常人类HC1-INH蛋白的基因治疗载体的一次性给药。目标是达到持续、长期的血浆C1-INH治疗水平，以防止血管水肿发作，而不需要重复注射蛋白质。我们将正常的HC1-INH基因序列克隆到腺相关血清型r.10(AAVr.10)病毒载体中，构建了AAVr.10hc1-INH载体，并设计了一种c1-INH缺陷小鼠模型来检测治疗效果。我们提出了三个特定的目标：目的1.在野生型小鼠体内展示AAVr.10hc1-INH在体内的功能性人c1-INH蛋白水平。目的2.建立一种表型类似于HAE的C1-异烟肼缺陷小鼠模型。目的3.利用AIM 2建立的小鼠模型，证明一次全身注射AAVRH.10hC1-INH可逆转小鼠c1-INH缺陷表型，并恢复c1-INH的正常功能水平。如果研究成功，AAVRH.10hc1-INH载体将在小鼠体内产生高水平、长期有效的功能性HC1-INH，其载体剂量可扩展到安全的人类剂量。进一步的成功将通过C1-INH缺陷小鼠的正常表型来证明，表现为血浆C4水平正常，血管通透性降低和粘膜下水肿。这项提议是对编码C1-INH基因的AAVRH.10基因转移载体的翻译开发，这样一次给药将为HAE的治疗提供持续、长期的治疗益处，从而消除重复给予C1-INH蛋白的需要。

 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.