Tissue-specific transcriptional targeting of a replication-competent retroviral vector
Tissue-specific transcriptional targeting of a replication-competent retroviral vector
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DOI：
10.1128/jvi.76.24.12783-12791.2002
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发表时间：
2002-12-01
影响因子：
5.4
通讯作者：
Kasahara, N
中科院分区：
文献类型：
--
作者：
Logg, CR;Logg, A;Kasahara, N
复制缺陷型病毒载体不能在体内有效地抑制肿瘤细胞，这阻碍了此类载体在癌症基因治疗中的成功应用。为了解决更有效的基因传递系统的需要，我们已经开发了基于鼠白血病病毒（MLV）的复制型逆转录病毒（RCR）载体。我们以前已经证明，这种载体能够在体内以非常高的效率转导实体瘤。虽然MLV感染对细胞分裂的天然需求赋予肿瘤细胞一定程度的特异性，但将RCR载体复制限制于肿瘤细胞的额外手段是期望的。在这里，我们研究了成功的组织特异性转录控制RCR载体复制的关键参数，通过替换各种。长度的MLV增强子/启动子，其具有源自高度前列腺特异性probasin（PB）启动子或源自PB启动子的更有效的合成变体的序列。我们评估了所得到的杂交长末端重复序列（LTR）的转录特异性和细胞类型特异性和含有这些LTR的载体的复制效率。PB启动子序列的掺入有效地限制了从LTR到前列腺衍生细胞的转录，并赋予了前列腺特异性RCR载体复制，但需要更强的合成启动子和在TATA盒附近保留天然MLV序列以获得最佳复制效率和特异性。因此，我们的研究结果确定启动子强度和定位在LTR内的重要决定因素，为实现高转导效率和严格的细胞类型特异性，在转录靶向RCR载体。
The inability of replication-defective viral vectors to efficiently transduce tumor cells in vivo has prevented the successful application of such vectors in gene therapy of cancer. To address the need for more efficient gene delivery systems, we have developed replication-competent retroviral (RCR) vectors based on murine leukemia virus (MLV). We have previously shown that such vectors are capable of transducing solid tumors in vivo with very high efficiency. While the natural requirement of MLV infection for cell division imparts a certain degree of specificity for tumor cells, additional means for confining RCR vector replication to tumor cells are desirable. Here, we investigated the parameters critical for successful tissue-specific transcriptional control of RCR vector replication by replacing various. lengths of the MLV enhancer/promoter with sequences derived either from the highly prostate-specific probasin (PB) promoter or from a more potent synthetic variant of the PB promoter. We assessed the transcriptional specificity of the resulting hybrid long terminal repeats (LTRs) and the cell type specificity and efficiency of replication of vectors containing these LTRs. Incorporation of PB promoter sequences effectively restricted transcription from the LTR to prostate-derived cells and imparted prostate-specific RCR vector replication but required the stronger synthetic promoter and retention of native MLV sequences in the vicinity of the TATA box for optimal replicative efficiency and specificity. Our results have thus identified promoter strength and positioning within the LTR as important determinants for achieving both high transduction efficiency and strict cell type specificity in transcriptionally targeted RCR vectors.