Safety of arylsulfatase a overexpression for gene therapy of metachromatic leukodystrophy
Safety of arylsulfatase a overexpression for gene therapy of metachromatic leukodystrophy
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DOI：
10.1089/hum.2007.048
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发表时间：
2007-09-01
影响因子：
4.2
通讯作者：
Biffi, A.
中科院分区：
文献类型：
--
作者：
Capotondo, A.;Cesani, M.;Biffi, A.
基于造血干/祖细胞（HSPC）或直接中枢神经系统（CNS）基因转移的异染性脑白质营养不良（MLD）的成功基因治疗方法强调了对高水平芳基硫酸酯酶A（ARSA）表达的需求，以实现对小鼠模型中的疾病表现的校正。因此，全面评估ARSA表达高于生理水平的安全性是这些方法临床转化的先决条件。在这里，使用慢病毒载体（LV），我们产生了两个相关的模型，在转导细胞中的ARSA过表达的后果进行严格的评估。我们首先证明了ARSA在人类HSPCs中的过表达并不影响其在克隆形成试验和新生儿hernatochimeric小鼠模型中的克隆形成和多谱系分化能力。此外，我们研究了ARSA在所有身体组织中的过表达，通过LV产生ARSA酶的过表达高达正常范围的15倍以上的转基因小鼠，并在其基因组中携带LV的多个拷贝。这些小鼠的表征证明了ARSA过表达在两个主要基因治疗靶点HSPC和神经元中的安全性，在超生理酶水平存在下维持造血和神经系统的复杂功能。在ARSA过表达HSPC和转基因小鼠中测试了依赖于相同的常见激活剂硫酸酯酶修饰因子-1（SUMF 1）的其他硫酸酯酶的活性，排除了饱和现象的发生。总的来说，这些数据表明，从临床转化的角度来看，ARSA过表达的治疗水平可以安全地实现。此外，他们展示了一个实验平台，用于临床前评估新基因治疗方法的安全性。
Successful gene therapy approaches for metachromatic leukodystrophy (MLD), based either on hematopoietic stem/progenitor cells (HSPCs) or direct central nervous system (CNS) gene transfer, highlighted a requirement for high levels of arylsulfatase A (ARSA) expression to achieve correction of disease manifestations in the mouse model. Full assessment of the safety of ARSA expression above physiological levels thus represents a prerequisite for clinical translation of these approaches. Here, using lentiviral vectors (LVs), we generated two relevant models for the stringent evaluation of the consequences of ARSA overexpression in transduced cells. We first demonstrated that ARSA overexpression in human HSPCs does not affect their clonogenic and multilineage differentiation capacities in clonogenic assays and in a neonatal hernatochimeric mouse model. Further, we studied ARSA overexpression in all body tissues by generating transgenic mice overexpressing the ARSA enzyme by LV up to 15-fold above the normal range and carrying multiple copies of LV in their genome. Characterization of these mice demonstrated the safety of ARSA overexpression in two main gene therapy targets, HSPCs and neurons, with maintenance of the complex functions of the hematopoietic and nervous system in the presence of supraphysiological enzyme levels. The activity of other sulfatases dependent on the same common activator, sulfatase-modifying factor-1 (SUMF1), was tested in ARSA-over-expressing HSPCs and in transgenic mice, excluding the occurrence of saturation phenomena. Overall, these data indicate that from the perspective of clinical translation, therapeutic levels of ARSA overexpression can be safely achieved. Further, they demonstrate an experimental platform for the preclinical assessment of the safety of new gene therapy approaches.