Promoter trapping reveals significant differences in integration site selection between MLV and HIV vectors in primary hematopoietic cells
Promoter trapping reveals significant differences in integration site selection between MLV and HIV vectors in primary hematopoietic cells
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DOI：
10.1182/blood-2004-03-0798
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发表时间：
2005-03-15
期刊：
影响因子：
20.3
通讯作者：
Naldini, L
中科院分区：
文献类型：
--
作者：
De Palma, M;Montini, E;Naldini, L
最近的报道表明，人类免疫缺陷病毒（HIV）和小鼠白血病病毒（MLV）载体优先整合到活性基因中。在这里，我们使用了一种基于遗传捕获的新方法来快速标记几千个整合位点，并发现MLV载体比HIV载体更有效地捕获细胞启动子。值得注意的是，1 / 5的MLV整合在不同的细胞系和原代造血细胞中捕获了一个活性启动子。这种频率在生长刺激淋巴细胞中更高。我们发现MLV和HIV载体的不同行为依赖于转录基因内不同的整合模式。基于mlv的陷阱表现出强烈的启动子-近端整合倾向，从而导致高效的报告基因表达，而基于hiv的陷阱则整合了整个转录单位，并受到与启动子和靶基因阅读框的距离的限制。我们的研究结果表明，MLV具有与细胞启动子建立转录相互作用的强烈倾向，这种行为可能已经进化为增强前病毒表达，并可能增加插入突变的风险。启动子捕获效率提供了一个方便的读数，以评估载体及其侧翼基因在整合位点之间的转录相互作用，并进行比较。不同细胞类型和不同生长条件下的整合位点选择。(c) 2005年由美国血液学会出版。
Recent reports have indicated that human immunodeficiency virus (HIV) and murine leukemia virus (MLV) vectors preferentially integrate into active genes. Here, we used a novel approach based on genetic trapping to rapidly score several thousand integration sites and found that MLV vectors trapped cellular promoters more efficiently than HIV vectors. Remarkably, 1 in 5 MLV integrations trapped an active promoter in different cell lines and primary hematopoietic cells. Such frequency was even higher in growth-stimulated lymphocytes. We show that the different behavior of MLV and HIV vectors was dependent on a different integration pattern within transcribed genes. Whereas MLV-based traps showed a strong bias for promoter-proximal integration leading to efficient reporter expression, HIV-based traps integrated throughout transcriptional units and were limited for expression by the distance from the promoter and the reading frame of the targeted gene. Our results indicate a strong propensity of MLV to establish transcriptional interactions with cellular promoters, a behavior that may have evolved to enhance proviral expression and may increase the insertional mutagenesis risk. Promoter trapping efficiency provides a convenient readout to assess transcriptional interactions between the vector and its flanking genes at the integration site and to compare. integration site selection among different cell types and in different growth conditions. (c) 2005 by The American Society of Hematology.