High-level human adenosine deaminase expression in dog skin fibroblasts is not sustained following transplantation.
High-level human adenosine deaminase expression in dog skin fibroblasts is not sustained following transplantation.
复制标题
移植后，狗皮肤成纤维细胞中的高水平人腺苷脱氨酶表达不会持续。
DOI：
10.1089/hum.1993.4.1-3
复制
发表时间：
1993
影响因子：
4.2
通讯作者：
Osborne,WR
中科院分区：
文献类型：
--
作者：
Ramesh,N;Lau,S;Palmer,TD;Storb,R;Osborne,WR
原代皮肤成纤维细胞是逆转录病毒介导的基因治疗的一个有吸引力的靶组织；然而，治疗基因的瞬时表达在一些啮齿动物模型中一直是一个反复出现的问题。基因表达的逐渐减少可能是组织或物种特有的。为了进一步研究这一现象，我们监测了人腺苷脱氨酶（ADA）在移植给比格犬的转基因皮肤成纤维细胞中的表达。在培养中，转导的犬成纤维细胞表达了高水平的人ADA活性（每小时每毫克可溶性蛋白代谢33.6 μ摩尔腺苷），而未处理的对照细胞（1.3 μ摩尔/小时·毫克蛋白）则表达了高水平的人ADA活性。移植后2周，移植物中含有的人ADA酶活性是内源性犬ADA酶的4倍。然而，到10周时，人类ADA的表达已检测不到。当人类ADA表达量大幅降低时，DNA分析显示存在载体序列。这些结果与在啮齿动物模型中观察到的结果直接相似，表明逆转录病毒载体失活是一种组织特异性机制，而不是物种特异性机制。
Primary skin fibroblasts are an attractive target tissue for retroviral-mediated gene therapy; however, transient expression of therapeutic genes has been a recurrent problem in several rodent models. The gradual decrease in gene expression could be tissue or species specific. To investigate the phenomenon further, human adenosine deaminase (ADA) expression was monitored in genetically modified skin fibroblasts transplanted in beagle dogs. In culture, transduced canine fibroblasts expressed high levels of human ADA activity (33.6 μmoles adenosine metabolized per hour per milligram of soluble protein) in comparison to canine ADA in untreated control cells (1.3 μmole/hr · mg protein) and for 2 weeks following transplantation, the graft contained up to four-fold more enzyme activity from human ADA than the endogenous canine enzyme. However, by 10 weeks, human ADA expression was undetectable. At the time when human ADA expression was greatly reduced, DNA analysis showed the presence of vector sequences. These results directly parallel those observed in rodent models and suggest retroviral vector inactivation is a tissue-specific rather than species-specific mechanism.