Kim J H, McLinden R J, Mosca J D, Vahey M T, Greene W C, Redfield R R
University of Maryland, Medical Biotechnology Center, Baltimore 21201, USA.
J Acquir Immune Defic Syndr Hum Retrovirol. 1996 Aug 1;12(4):343-51. doi: 10.1097/00042560-199608010-00003.
The life cycle of human immunodeficiency virus type 1 (HIV-1) is critically dependent on the transregulatory proteins Tat and Rev. Tat increases the production of HIV-specific mRNAs by direct binding to the transactivation response (TAR) element located at the 5' end of all HIV transcripts. In contrast, Rev uses a complex RNA stem loop structure, the Rev response element (RRE), which is found in full-length and singly spliced HIV transcripts. Rev is required for the cytoplasmic expression of full-length mRNAs encoding Gag, Pol, and Env structural proteins. The complex intracellular interactions between Tat, Rev, host cell factors, and their respective RNA response elements should be susceptible to interdiction by genetic therapies designed to introduce and express novel genetic information. We show that the expression of antisense RREs inhibited the cytoplasmic expression of RRE containing HIV-1 transcripts. HIV-based retroviral vectors containing either the antisense (-) or sense (+) RREs inhibited HIV replication in transient transfections. The production of full-length HIV mRNA was also decreased significantly by the expression of RREs in either orientation. Interestingly, there was a paradoxic increase in HIV p24 gag production at low levels of inhibitor; this effect may have been the result of encapsidation of RRE-containing HIV-based retroviral vectors. The data suggest that the introduction and inducible expression of RRE-containing, HIV-based retroviral vectors may have therapeutic value in HIV infection.
1型人类免疫缺陷病毒（HIV-1）的生命周期严重依赖于反式调节蛋白Tat和Rev。Tat通过直接结合位于所有HIV转录本5'端的反式激活应答（TAR）元件来增加HIV特异性mRNA的产生。相比之下，Rev利用一种复杂的RNA茎环结构，即Rev应答元件（RRE），该元件存在于全长和单剪接的HIV转录本中。Rev是编码Gag、Pol和Env结构蛋白的全长mRNA在细胞质中表达所必需的。Tat、Rev、宿主细胞因子及其各自的RNA应答元件之间复杂的细胞内相互作用应该容易受到旨在引入和表达新遗传信息的基因治疗的阻断。我们表明，反义RRE的表达抑制了含有RRE的HIV-1转录本在细胞质中的表达。含有反义（-）或正义（+）RRE的基于HIV的逆转录病毒载体在瞬时转染中抑制了HIV复制。RRE以任何一种方向表达也显著降低了全长HIV mRNA的产生。有趣的是，在低水平抑制剂存在时，HIV p24 gag的产生出现了反常增加；这种效应可能是含有RRE的基于HIV的逆转录病毒载体被包装的结果。这些数据表明，引入并可诱导表达含有RRE的基于HIV的逆转录病毒载体可能对HIV感染具有治疗价值。
