A point mutation in the HIV-1 Tat responsive element is associated with postintegration latency
A point mutation in the HIV-1 Tat responsive element is associated with postintegration latency
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DOI：
10.1073/pnas.93.13.6377
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发表时间：
1996-06-25
影响因子：
11.1
通讯作者：
Verdin, E
中科院分区：
文献类型：
--
作者：
Emiliani, S;VanLint, C;Verdin, E
对HIV-1在ACH 2细胞中整合后潜伏期机制的研究表明，这些细胞经外源性达特处理后不能增加HIV-1的产生。我们推断ACH 2细胞中的缺陷涉及达特反应，我们分析了整合在ACH 2中的病毒的tat cDNA和达特反应元件（TAR）的序列。达特（Tat）cDNA序列与HIVLAI的cDNA序列密切相关，编码的蛋白质在长末端重复序列（LTR）反式激活方面具有完全功能。然而，克隆ACH 2中对应于5 '-LTR的区域，发现TAR中存在点突变（C-37-->T）。这种突变在瞬时转染试验中损害了LTR的达特反应性，并且在用十四烷酰佛波醇醋酸酯或肿瘤坏死因子α型（TNF-alpha）处理的细胞中补充了测量的缺陷。TAR中的补偿突变（G（28）--> A），旨在重建TAR发夹中的碱基配对，恢复野生型达特反应性。当（C-37 --> T）突变被引入HIV-1的感染性克隆中，在TNF-α不存在的情况下没有测量到病毒产生，而当在TNF-α存在的情况下进行感染时或当补偿突变（G（28）--> A）被引入TAR时观察到完全互补，这些实验确定了一种与HIV-1潜伏期相关的新突变，并表明Tat-TAR轴的改变可能是感染个体潜伏表型的关键决定因素。
Study of the mechanism of HIV-1 postintegration latency in the ACH2 cell line demonstrates that these cells failed to Increase HIV-1 production following treatment with exogenous Tat, Reasoning that the defect in ACH2 cells involves the Tat response, we analyzed the sequence of tat cDNA and Tat responsive element (TAR) from the virus integrated in ACH2. Tat cDNA sequence is closely related to that of HIVLAI, and the encoded protein is fully functional in terms of long terminal repeat (LTR) transactivation, Cloning of a region corresponding to the 5'-LTR from ACH2, however, identified a point mutation (C-37-->T) in TAR. This mutation impaired Tat responsiveness of the LTR in transient transfection assays, and the measured defect was complemented in cells that had been treated with tetradecanoyl phorbol acetate or tumor necrosis factor type alpha (TNF-alpha). A compensatory mutation in TAR (G(28) --> A), designed to reestablish base pairing in the TAR hairpin, restored wild-type Tat responsiveness. When the (C-37 --> T) mutation was introduced in an infectious clone of HIV-1, no viral production was measured in the absence of TNF-alpha, whereas full complementation was observed when the infection was conducted in the presence of TNF-alpha or when a compensatory mutation (G(28) --> A) was introduced into TAR, These experiments identify a novel mutation associated with HIV-1 latency and suggest that alterations in the Tat-TAR axis can be a crucial determinant of the latent phenotype in infected individuals.