Analysis of human immunodeficiency virus type 1 transcriptional elongation in resting CD4+ T cells in vivo
Analysis of human immunodeficiency virus type 1 transcriptional elongation in resting CD4+ T cells in vivo
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DOI：
10.1128/jvi.78.17.9105-9114.2004
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发表时间：
2004-09-01
影响因子：
5.4
通讯作者：
Siliciano, RF
中科院分区：
文献类型：
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作者：
Lassen, KG;Bailey, JR;Siliciano, RF
人类免疫缺陷病毒1型(HIV-1)在静止记忆的CD4(+)T细胞中的稳定潜伏库为根除感染提供了障碍，即使在接受高效抗逆转录病毒治疗的患者中也是如此。潜伏期的潜在机制包括无法获得整合的病毒基因组，缺乏关键的宿主转录因子，过早终止HIV-1RNA，以及异常剪接模式。为了区分这些机制，我们从接受高效抗逆转录病毒治疗的患者中分离出极其纯净的静息CD4(+)T细胞群。这些细胞不会产生病毒，但如果受到适当的刺激，它们仍有能力产生病毒。在纯化的静息CD4(+)T细胞中检测HIV-1转录产物。虽然短的、过早终止的HIV-1转录本被认为是潜伏感染细胞的标志，但在静止的CD4(+)T细胞的纯化群体中还没有发现短转录本的产生。通过将RNA分离为多聚腺化和非多腺化部分，我们发现，接受高效抗逆转录病毒治疗的患者的静息CD4(+)T细胞产生的流产转录本缺乏多(A)尾巴，并在第181位核苷酸之前终止。在静息的CD4(+)T细胞中，短转录本占HIV-1总转录子库的主导地位。进行性的，多腺化的HIV-1mRNAs也存在于低水平。发现了未剪接和多重剪接形式。综上所述，这些结果表明，接受高效抗逆转录病毒治疗的患者静息CD4(+)T细胞感染的非生产性性质并不是由于转录起始或延伸水平的绝对阻断，而是多个步骤的相对低效。
A stable latent reservoir for human immunodeficiency virus type 1 (HIV-1) in resting memory CD4(+) T cells presents a barrier to eradication of the infection even in patients on highly active antiretroviral therapy. Potential mechanisms for latency include inaccessibility of the integrated viral genome, absence of key host transcription factors, premature termination of HIV-1 RNAs, and abnormal splicing patterns. To differentiate among these mechanisms, we isolated extremely pure populations of resting CD4(+) T cells from patients on highly active antiretroviral therapy. These cells did not produce virus but retained the capacity to do so if appropriately stimulated. Products of HIV-1 transcription were examined in purified resting CD4(+) T cells. Although short, prematurely terminated HIV-1 transcripts have been suggested as a marker for latently infected cells, the production of short transcripts had not been previously demonstrated in purified populations of resting CD4(+) T cells. By separating RNA into polyadenylated and nonpolyadenylated fractions, we showed that resting CD4(+) T cells from patients on highly active antiretroviral therapy produce abortive transcripts that lack a poly(A) tail and that terminate prior to nucleotide 181. Short transcripts dominated the pool of total HIV-1 transcripts in resting CD4(+) T cells. Processive, polyadenylated HIV-1 mRNAs were also present at a low level. Both unspliced and multiply spliced forms were found. Taken together, these results show that the nonproductive nature of the infection in resting CD4(+) T cells from patients on highly active antiretroviral therapy is not due to absolute blocks at the level of either transcriptional initiation or elongation but rather relative inefficiencies at multiple steps.