Analysis of transition from long-term nonprogressive to progressive infection identifies sequences that may attenuate HIV type 1
Analysis of transition from long-term nonprogressive to progressive infection identifies sequences that may attenuate HIV type 1
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DOI：
10.1089/088922201753197060
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发表时间：
2001-10-01
影响因子：
1.5
通讯作者：
Weiser, B
中科院分区：
文献类型：
--
作者：
Fang, GW;Burger, H;Weiser, B
长期非进行性人类免疫缺陷病毒1型（HIV-1）感染及其向进行性感染的转变为鉴定HIV-1衰减和发病机制的分子决定因素提供了机会。我们研究了一个从长期非进展性感染到迅速进展性感染的个体。由于血浆中的HIV-1 RNA基因组代表了复制病毒，我们开发了一种从血浆中克隆全长HIV-1 RNA基因组的技术，并利用该技术在转化前和转化过程中获得了该个体的克隆。检测的大多数克隆具有传染性，表明RNA基因组编码有活力的病毒。对20个完整的HIV-1 RNA基因组序列的分析揭示了在感染的两个阶段发现的序列之间的一个主要差异。在非进展阶段，优势序列在sp1结合位点和长末端重复序列（LTR） U3部分的邻近启动子中存在较大的缺失；当感染进展时，所有的病毒都具有完整的Sp1和启动子序列，并且来自先前存在的一个小物种。对跨越7年的5个时间点获得的184个LTR区克隆的分析证实了这一转变。在体外实验中，缺失下调了ltr驱动的报告基因转录。此外，从完整的病毒RNA基因组中预测的细胞毒性T淋巴细胞（CTL）表位分析显示，随着时间的推移，有多个潜在的逃逸突变体积累。这些研究表明，在非进展阶段，Sp1增强子-启动子缺失可能在减少复制中发挥作用，从而减弱HIV-1。CTL逃逸突变体的积累表明免疫监视的破坏可能导致完整病毒的增殖，从而导致疾病的快速进展。这些数据揭示了病毒和免疫相互作用的特征，从长期非进展到迅速进展感染的转变。
Long-term nonprogressive human immunodeficiency virus type 1 (HIV-1) infection and its transition to progressive infection presents an opportunity to identify the molecular determinants of HIV-1 attenuation and pathogenesis. We studied an individual who underwent a transition from long-term nonprogressive to rapidly progressive infection. Because HIV-1 RNA genomes in plasma represent replicating virus, we developed a technique to clone full-length HIV-1 RNA genomes from plasma and used this technique to obtain clones from this individual before and during the transition. Most clones assayed were infectious, demonstrating that the RNA genomes encoded viable virus. Analysis of 20 complete HIV-1 RNA genomic sequences revealed one major difference between sequences found during the two phases of infection. During the nonprogressive phase, the predominant sequences had a large deletion in an Sp1-binding site and adjacent promoter in the U3 part of the long terminal repeat (LTR); when the infection became progressive, all viruses had intact Sp1 and promoter sequences and were derived from a minor species present earlier. Analysis of 184 clones of the LTR region obtained at five time points spanning a 7-year period confirmed this switch. In an in vitro assay, the deletion downregulated LTR-driven transcription of a reporter gene. In addition, analysis of cytotoxic T lymphocyte (CTL) epitopes predicted from the complete viral RNA genomes revealed multiple potential escape mutants that accumulated by the time of progression. These studies suggest that during the nonprogressive phase, the Sp1 enhancer-promoter deletion is likely to have played a role in decreasing replication, thereby attenuating HIV-1. The accumulation of CTL escape mutants suggests that a breakdown in immunologic surveillance may have allowed proliferation of intact virus, thus leading to rapid disease progression. These data reveal the viral and immune interactions characterizing a transition from long-term nonprogressive to rapidly progressive infection.