Physiological regulation of transgene expression by a lentiviral vector containing the A2UCOE linked to a myeloid promoter
Physiological regulation of transgene expression by a lentiviral vector containing the A2UCOE linked to a myeloid promoter
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DOI：
10.1038/gt.2011.167
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发表时间：
2012-10-01
期刊：
影响因子：
5.1
通讯作者：
Grez, M.
中科院分区：
文献类型：
--
作者：
Brendel, C.;Mueller-Kuller, U.;Grez, M.
防止表观遗传沉默是未来基因治疗载体的理想特征，特别是对于那些转基因表达不会赋予基因转导细胞生长优势的应用。普遍存在的染色质开放元件(UCOE)由包含人类HNRPA2B1-CBX3看家基因(A2UCOE)的双重差异转录启动子的无甲基化CpG岛组成，已被证明保护构成活性的异源启动子免受表观遗传修饰和染色体位置的影响。然而，目前还不清楚这种成分是否可以用来提高组织特异性增强子/启动子的表达，同时保持造血细胞的组织特异性。在这里，我们评估了A2UCOE与髓系特异性髓系相关蛋白8(MRP8)启动子结合从自失活慢病毒载体在体外和体内针对髓系细胞特异性转基因表达的潜力。A2UCOE的加入不干扰髓系分化过程中MRP8启动子活性的特异性上调，并介导了髓系细胞持续的和载体复制依赖的表达。值得注意的是，在P19胚胎癌细胞系中，A2UCOE不能保护MRP8启动子不受甲基化的影响，这表明该元件保持了细胞启动子固有的表观遗传状态和转录活性。因此，A2UCOE可以在基因治疗载体中代表一个有用的保护性遗传元件，确保组织特异性启动子的生理转录调节独立于染色体整合位点。
Protection against epigenetic silencing is a desirable feature of future gene therapy vectors, in particular for those applications in which transgene expression will not confer growth advantage to gene-transduced cells. The ubiquitous chromatin opening element (UCOE) consisting of the methylation-free CpG island encompassing the dual divergently transcribed promoters of the human HNRPA2B1-CBX3 housekeeping genes (A2UCOE) has been shown to shield constitutive active heterologous promoters from epigenetic modifications and chromosomal position effects. However, it is unclear if this element can be used to improve expression from tissue-specific enhancer/promoters, while maintaining tissue specificity in hematopoietic cells. Here, we evaluated the potential of the A2UCOE in combination with the myeloid-specific myeloid related protein 8 (MRP8) promoter to target transgene expression specifically to myeloid cells in vitro and in vivo from a self-inactivating lentiviral vector. The inclusion of the A2UCOE did not interfere with specific upregulation of MRP8 promoter activity during myeloid differentiation and mediated sustained and vector copy-dependent expression in myeloid cells. Notably, the A2UCOE did not protect the MRP8 promoter from methylation in the P19 embryonal carcinoma cell line, suggesting that this element maintains the inherent epigenetic state and transcriptional activity of cellular promoters in their native configuration. Thus, the A2UCOE could represent a useful protective genetic element in gene therapy vectors, ensuring physiological transcriptional regulation of tissue-specific promoters independent of the chromosomal integration site.