Achromatopsia - Disease Mechanisms and Cone-Directed Gene Therapy

全色盲 - 疾病机制和视锥细胞定向基因治疗

• 批准号: 8446968
• 负责人: Andras Komaromy
• 金额: $ 39.85万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-01 至 2015-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8446968
• 关键词: Affect; Age related macular degeneration; Age-Years; Anatomy; Animal Model; Biogenesis; Biological Preservation; Blindness; Canis familiaris; Catalytic RNA; Color; Color Visions; Complementary DNA; Data; Defect; Development; Disease; Disease model; Evaluation; Eye; Functional disorder; Gene Expression; Gene Proteins; Generic Drugs; Genomics; Goals; Health; Hereditary Disease; Human; Inherited; Lead; Life; Mediating; Metric; Missense Mutation; Modality; Modeling; Molecular; Monitor; Mus; Mutation; Patients; Pattern; Phase I Clinical Trials; Phenotype; Photoreceptors; Process; Proteins; Publishing; Rattus; Recombinant adeno-associated virus (rAAV); Reporting; Research Proposals; Retina; Retinal; Retinal Cone; Retinal Diseases; Retinitis Pigmentosa; Rodent Model; Safety; Specificity; Staging; Structure; Structure of retinal pigment epithelium; Testing; Therapeutic; Time; Tissues; Toxic effect; Transgenes; Translations; Treatment outcome; Vision; Visual Acuity; achromatopsia; adeno-associated viral vector; age effect; base; cyclic-nucleotide gated ion channels; design; disease phenotype; early onset; gain of function mutation; gene replacement; gene replacement therapy; gene therapy; improved; loss of function mutation; man; monolayer; mutant; neurotrophic factor; prevent; promoter; public health relevance; restoration; success; transgene expression; visual performance

DESCRIPTION (provided by applicant): Cone photoreceptors are responsible for central visual acuity, color vision, and photopic vision and are therefore critical for visual performance in daily human life. As such, it is of utmost importance to target cones when designing therapeutic treatment for retinal diseases such as achromatopsia, cone dystrophies, and cone-rod dystrophies that primarily affect cones. However, cone rescue is of even greater importance in diseases where cones are affected secondarily, such as in retinitis pigmentosa (RP) and most forms of age-related macular degeneration (AMD), the leading cause of vision loss in people over 65 years of age. The overarching aim of this proposal is to develop 2 natural canine achromatopsia models as a platform for recombinant adeno-associated virus (rAAV)-mediated cone-directed gene therapy. In both canine models, loss-of-function mutations in the cone cyclic nucleotide-gated channel beta subunit (CNGB3) lead to a disease phenotype identical to human achromatopsia. Mutations in CNGB3 are the most common cause for achromatopsia in man, making the 2 canine strains the optimal animal model in which to carry out cone-targeted gene replacement studies with translational potential. The long-term success of rAAV-mediated retinal gene therapy for primary defects of the retinal pigment epithelium (RPE) has been demonstrated in several species, including dogs. Because of their successful, stable, and apparently safe transgene expression, these studies are now in Phase 1 clinical trials. In contrast to RPE defects, the treatment of primary photoreceptor diseases is more difficult, and previous gene therapy studies have shown variable success. The hypothesis to be tested in this proposal is that cone function and structure can be restored, and degeneration prevented, using rAAV-mediated cone-directed delivery of wildtype CNGB3 cDNA under control of cone-specific promoters. To test this hypothesis, we specifically propose to 1) optimize rAAV vectors for targeted gene expression in cones and 2) maximize preservation of cone function following cone-specific expression of CNGB3 cDNA in the two canine models. Results from the first two aims will provide data regarding the efficiency, safety, and limitations of the treatment. In the final aim, functional, structural, and molecular disease correlates of the canine CNGB3 mutations will be characterized and their potential reversal following successful gene therapy assessed in order to more fully understand disease mechanisms and to provide disease metrics for establishing an optimal therapeutic time window. The canine achromatopsia models offer unique opportunities for proof-of-principle of cone-directed gene therapy and for eventual translation to patients.

描述（由申请人提供）：锥形光感受器负责中央视敏度，色觉和光波视觉，因此对于每日人类生活中的视觉表现至关重要。因此，在设计视网膜疾病（如achromoptia，锥形营养不良和锥体杆状营养不良）等视网膜疾病治疗时，靶向锥体至关重要，主要影响锥体。但是，锥体救援在圆锥体受到次要影响的疾病中的重要性甚至更为重要，例如色素炎（RP）和大多数与年龄相关的黄斑变性（AMD），这是65岁以上视力丧失的主要原因。该提案的总体目的是开发2种天然犬Achromomatia模型，作为重组腺相关病毒（RAAV）介导的锥体指导基因治疗的平台。在两个犬种模型中，锥体环核苷酸门控通道β亚基（CNGB3）中的功能丧失突变导致与人achromomatia相同的疾病表型。 CNGB3中的突变是人类六斑瘤的最常见原因，这使得两种犬种成为最佳动物模型，在该模型中，可以在其中进行具有转化潜力的锥形基因替代研究。 RAAV介导的视网膜基因治疗对视网膜色素上皮（RPE）的主要缺陷的长期成功已在包括狗在内的几种物种中证明。由于它们成功，稳定且显然是安全的转基因表达，因此这些研究现在正在1阶段临床试验中。与RPE缺陷相反，原发性光感受器疾病的治疗更加困难，并且先前的基因疗法研究显示出可变的成功。该提案中要检验的假设是，可以使用RAAV介导的锥体指导的野生型CNGB3 cDNA在锥体特异性启动子控制下使用RAAV介导的锥体指导的锥体指导的递送来恢复锥功能和结构。为了检验这一假设，我们特别提出了1）在锥体中优化靶向基因表达的RAAV载体，以及2）在两个犬模型中CNGB3 cDNA锥体表达后，最大化锥功能保存。前两个目标的结果将提供有关治疗效率，安全性和局限性的数据。在最终目的中，将表征犬CNGB3突变的功能，结构和分子疾病相关性，并评估成功的基因治疗后其潜在的逆转，以便更充分地了解疾病机制并提供疾病指标，以建立最佳治疗时间窗口。犬肉眼瘤模型为锥体指导基因疗法的原理证明提供了独特的机会，并最终向患者翻译。