NEF STIMULATES HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 PROVIRAL DNA-SYNTHESIS
NEF STIMULATES HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 PROVIRAL DNA-SYNTHESIS
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DOI：
10.1128/jvi.69.8.5048-5056.1995
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发表时间：
1995-08-01
影响因子：
5.4
通讯作者：
TRONO, D
中科院分区：
文献类型：
--
作者：
AIKEN, C;TRONO, D
人类免疫缺陷病毒1型（HIV-1）的Nef蛋白刺激病毒的感染性，这种表型的机制进行了研究，含有破坏nef基因的病毒在单轮感染中的感染性比野生型HIV-1低4至40倍。Nef介导的HIV-1感染性的刺激依赖于Nef与质膜的结合，并且当Nef在病毒生产者而不是靶细胞中以反式提供时可以观察到。观察到nef缺陷型（Delta Nef）病毒粒子的感染性受损，无论这些细胞中是否存在CD 4。此外，它与病毒进入的方式无关，因为它不能通过用嗜酸性鼠白血病病毒包膜糖蛋白假型化Env（-）HIV-1病毒粒子来拯救。正如从该结果预测的，野生型和Delta Nef病毒粒子以相等的效率进入细胞。然而，尽管它们在病毒基因组RNA中的含量和逆转录酶活性正常，但Delta Nef病毒一旦在几种细胞类型（包括外周血淋巴细胞）中内化，其进行逆转录的能力就受到限制。由于Nef在病毒体中似乎并不丰富，这些结果表明Nef在生产细胞中起作用，以允许产生完全胜任完成进入后步骤的颗粒，从而导致HIV-1基因组的有效逆转录。使用反式互补分析，我们发现，Nef蛋白从一些主要的HIV-1分离株，以及在较温和的程度上，那些从HIV-2（ST）和SIVMAC 239可以增强感染性的Delta Nef HIV-1。这表明Nef介导的前病毒DNA合成的刺激是高度保守的，并且可能在体内起重要作用。
The Nef protein of human immunodeficiency virus type 1 (HIV-1) stimulates viral infectivity, The mechanism of this phenotype was investigated Viruses containing disrupted nef genes were 4 to 40 times less infectious than wild-type HIV-1 in a single-round infection. The Nef-mediated stimulation of HIV-1 infectivity was dependent on the association of Nef with the plasma membrane and could be observed when Nef was provided in trans in the virus producer but not target cells. The impaired infectiousness of nef-defective (Delta Nef) virions was observed whether or not CD4 was present in either of these cells. Furthermore, it was independent of the mode of viral entry, since it was not rescued by pseudotyping Env(-) HIV-1 virions with the amphotropic murine leukemia virus envelope glycoproteins. As predicted from this result, wild-type and Delta Nef virions entered cells with equal efficiencies. However, despite their normal content in viral genomic RNA and reverse transcriptase activity Delta Nef viruses were limited in their ability to perform reverse transcription once internalized in several cell types, including peripheral blood lymphocytes. Since Nef does not appear to be abundant in virions, these results suggest that Nef acts in producer cells to allow the generation of particles fully competent for completing steps that follow entry, leading to efficient reverse transcription of the HIV-1 genome. Using a trans complementation assay, we found that Nef proteins from a number of primary HIV-1 isolates as well as, to a milder degree, those from HIV-2(ST) and SIVMAC239 could enhance the infectivity of Delta Nef HIV-1. This indicates that the Nef-mediated stimulation of proviral DNA synthesis is highly conserved and likely plays an important role in vivo.