The Implications of Dystrophin-Specific T cells for DMD gene Correction

项目总结（见说明）：肌营养不良蛋白特异性T细胞对DMD基因校正的意义在杜氏肌营养不良症（DMD）的小鼠和狗模型中进行的原理验证研究已经确定基因替代疗法是一种有前途的治疗策略。尝试将从临床前学到的原则应用于临床方案并不能预测肌营养不良蛋白特异性T细胞靶向突变下游肌纤维上的新表位。在一种情况下，这些回复突变纤维上表达，这一发现与预测这些纤维的耐受作用的公理相反。另一种治疗模式，庆大霉素诱导的突变抑制，被证明同样混淆，因为肌营养不良蛋白特异性T细胞分离从血液和肌肉治疗后。这些观察结果需要进一步的研究，以实现成功的DMD基因校正策略。在目标1中，我们将描述DMD患者血液和肌肉中抗肌萎缩蛋白特异性T细胞的特性，这些患者具有良好的突变特征， 确定有多少患者表现出对肌营养不良蛋白的细胞免疫，并确定突变的肌营养不良蛋白内同源自身表位的位置。我们将研究抗肌萎缩蛋白特异性的CD 4+和CD 8 + T细胞的效应子功能。在目标2中，我们将特别关注糖皮质激素在幼稚受试者的指定三个月治疗计划中调节T细胞应答的作用。在这里，我们预期T细胞表型从效应/炎症到调节/抑制作用的变化。在目标3中，我们将使用AAVS.MCK.微肌养蛋白进行血管递送临床基因转移研究。我们可以通过血管输送转基因到恒河猴的特定腿部肌肉实现高水平的肌纤维转导。这为临床疗效奠定了基础。该研究的入选标准包括基于先前经验的目前确定的免疫屏障，并将增加项目1和2的发现。

PROJECT SUMMARY (See instructions): The Implications of Dystrophin-Speclfic T cells for DMD Gene Correction Proof-of-principle studies in mouse and dog models of Ducheime muscular dystrophy (DMD) have established that gene replacement therapy is a promising treatment strategy. Attempts to apply the tenets learned from pre-clinical to clinical protocols did not predict dystrophin-specific T cells targeting novel epitopes on muscle fibers downstream of the mutation. In one case these were expressed on revertant fibers, a finding contrary to the axiom that forecasts a tolerizing role for these fibers. Another treatment paradigm, gentamicin-induced mutation suppression, proved equally confounding because dystrophin-specific T cells were isolated fi-om the blood and muscle following treatment. These observations require further study to achieve success in gene correction strategies for DMD. In Aim 1 we will characterize the properties of dystrophin-specific T cells in the blood and muscle of DMD patients with well characterized mutations to determine how many patients exhibit cellular immunity to dystrophin and define the location of cognate selfepitopes within the mutated dystrophin protein. We will examine the effector fimctions of CD4+ and CD8+ T cells that are dystrophin specific. In Aim 2 we will look specifically at the role of glucocorticoids in modulating T cell response in a designated three-month treatment program of naive subjects. Here we anticipate a T cell phenotype change fi-om effector/inflammatory to a regulatory/suppressor role. In Aim 3 we will perform a vascular delivery clinical gene transfer study using AAVS.MCK.micro-dystrophin. We can achieve high levels of muscle fiber transduction through vascular delivery of transgene to specific leg muscles in the rhesus macaque. This sets the stage for clinical efficacy. The study inclusion criteria include currently identified immune barriers based on prior experience and will add findings that emerge from Projects 1 and 2.