Scrambling of the amino acids within the transmembrane domain of Vpu results in a simian-human immunodeficiency virus (SHIVTM) that is less pathogenic for pig-tailed macaques
Scrambling of the amino acids within the transmembrane domain of Vpu results in a simian-human immunodeficiency virus (SHIVTM) that is less pathogenic for pig-tailed macaques
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DOI：
10.1016/j.virol.2005.04.038
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发表时间：
2005-08-15
期刊：
影响因子：
3.7
通讯作者：
Stephens, EB
中科院分区：
文献类型：
--
作者：
Hout, DR;Gomez, ML;Stephens, EB
先前的研究已经表明，亚型B Vpu的transmembrame（TM）结构域增强了病毒体从细胞中的释放，并且一些研究已经表明，该结构域可以形成具有离子通道性质的寡聚体结构。到目前为止，还没有研究已经进行了评估的作用，该结构域在病毒发病机制中的猕猴模型的疾病。使用猴人类免疫缺陷病毒（SHIVKU-1bMC 33）的致病性分子克隆，我们已经产生了一种新的病毒，其中Vpu蛋白的跨膜结构域被打乱，但保持疏水性的性质（SHIVTM），这可能会破坏任何离子通道TM这种蛋白质的属性。表达Vpu作为与增强型绿色荧光蛋白（Vpu（TM）EGFP）的融合蛋白的载体表明，它被转运到与未修饰的Vpu蛋白相同的细胞内区室，但不下调CD 4的细胞表面表达。为了评估SHIVTM的致病性，用SHIVTM接种三只短尾猴，并监测6-8个月的CD 4（+）T细胞水平、病毒载量和vpu基因序列的稳定性。我们的研究结果表明，与亲本SHIVKU-1bMC 33不同，用SHIVTM接种猕猴在感染过程中不会引起严重的CD 4（+）T细胞损失。来自猕猴的连续PBMC样品分析的vpu基因的序列分析显示，乱序TM在感染过程中是稳定的。尸检时，组织检查显示病毒载量较低，接种致病亲本SHIVKU-1bMC 33病毒后，淋巴和非淋巴组织中未观察到常见病理。因此，这些结果首次表明Vpu的TM结构域有助于SHIVKU-1bMC 33在猪尾猕猴中的致病性。(C)2005年爱思唯尔公司All rights reserved.
Previous studies have shown that the transmembrame (TM) domain of the subtype B Vpu enhances virion release from cells and some studies have shown that this domain may form an oligomeric structure with properties of an ion channel. To date, no studies have been performed to assess the role of this domain in virus pathogenesis in a macaque model of disease. Using a pathogenic molecular clone of simian human immunodeficiency virus (SHIVKU-1bMC33), we have generated a novel virus in which the transmembrane domain of the Vpu protein was scrambled but maintained hydrophobic in nature (SHIVTM), which presumably would disrupt any ion channel TM properties of this protein. Vectors expressing the Vpu as a fusion protein with the enhanced green fluorescent protein (Vpu(TM)EGFP) indicate that it was transported to the same intracellular compartment as the unmodified Vpu protein but did not down-regulate cell surface expression of CD4. To assess the pathogenicity of SHIVTM, three pig-tailed macaques were inoculated with the SHIVTM and monitored for 6-8 months for CD4(+) T cell levels, viral loads and the stability of the sequence of the vpu gene. Our results indicated that unlike the parental SHIVKU-1bMC33, inoculation of macaques with SHIVTM did not cause a severe CD4(+) T cell loss over the course of their infections. Sequence analysis of the vpu gene analyzed from sequential PBMC samples derived from macaques revealed that the scrambled TM was stable during the course of infection. At necropsy, examination of tissues revealed low viral loads and none of the pathology commonly observed in lymphoid and non-lymphoid tissues following inoculation with the pathogenic parental SHIVKU-1bMC33 virus. Thus, these results show for the first time that the TM domain of Vpu contributes to the pathogenicity of SHIVKU-1bMC33 in pig-tailed macaques. (C) 2005 Elsevier Inc. All rights reserved.