Regulation of Outflow Facility by Gene Transfer

描述（由申请人提供）：这个正在进行的项目的一般假设是，通过基因转移调节流出通道细胞的基因表达，将比目前的常规药物以更特异性、更受调节和更持久的方式控制眼压升高。在过去的这些周期中，我们积累了大量关于基因转移到小梁网（TM）的知识和专业知识。我们已经确定了安全的病毒载体和候选基因，并且我们开发了第一个仅在需要时表达治疗产品的诱导载体。具体来说，我们证明了其中一种携带类固醇诱导的人金属肽酶I （MMP1）的病毒（adhgrei .MMP1）在类固醇存在时过表达该酶，而在没有类固醇存在时其表达恢复到基线水平。在这个大型动物模型中，将该载体注入羊体内降低并预防了类固醇引起的高血压，而突变体MMP1 （adhgre1 . mmmp1）则没有这种作用。由于糖皮质激素（GCs）的使用在当今的眼科实践中是如此重要，并且由于它们对IOP的副作用是如此具有破坏性，因此我们本资助期的目标是在我们的研究结果的基础上，在本项目结束时开发出一种治疗类固醇引起的高血压的临床基因疗法。我们打算按照具体目标分三个连续阶段实施该项目。在第一阶段（SA#1），我们将专注于最终目标向量的全面优化和开发。在第二阶段（SA#2），我们将使用大型动物模型（羊）来测量载体在抵消眼压升高、类固醇开/关开关期间的表达、途径方面的功效

DESCRIPTION (provided by applicant): The general hypothesis of this ongoing project has been that modulating gene expression of the outflow pathway cells by gene transfer would control elevated intraocular pressure (IOP) in a more specific, regulated and prolonged manner than current conventional drugs. During these past cycles we have accumulated extensive knowledge and expertise about gene transfer to the trabecular meshwork (TM). We have identified safe viral vectors and candidate genes, and we developed the first inducible vectors expressing the therapeutic product only when is needed. Specifically, we proved that one of our viruses carrying a steroid-inducible human metallopeptidase I (MMP1) (AdhGRE.MMP1) overexpressed the enzyme in the presence of steroids and returned its expression to baseline in their absence. Intracameral injection of this vector to sheep lowered and prevented steroid-induced hypertension in this large animal model, while administration of the mutant MMP1 (AdhGRE.mMMP1) did not. Because the use of glucocorticoids (GCs) is so essential in today's ophthalmology practice and because their side effect on IOP is so damaging, our goal for this grant period is to build on our findings and develop a clinical gene therapy treatment of steroid-induced hypertension by the end of this project. We intend to carry out the project in three consecutive phases which correlate with specific aims. On the first phase (SA#1), we will concentrate on the comprehensive optimization and development of the final targeting vector. On the second phase (SA#2) we will use the large animal model (sheep) for measuring the vector's efficacy in counteracting IOP elevation, expression during a steroid on/off switch, routes of administration and determination of the clinical relevant dose (CRD). On the third phase (SA#3) we will assess all major toxicity parameters, including clinical outcomes, immune responses, and biodistribution according to FDA guidelines for gene therapy viral vectors. We expect that completion of this project will provide all needed preclinical efficacy and safety requirements for setting up a Phase I clinical trial for the treatment of steroid glaucoma patients