Glycosylphosphatidylinositol Anchor Deficiency Attenuates the Production of Infectious HIV-1 and Renders Virions Sensitive to Complement Attack
Glycosylphosphatidylinositol Anchor Deficiency Attenuates the Production of Infectious HIV-1 and Renders Virions Sensitive to Complement Attack
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DOI：
10.1089/aid.2016.0046
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发表时间：
2016-10-01
影响因子：
1.5
通讯作者：
Yu, Qigui
中科院分区：
文献类型：
--
作者：
Amet, Tohti;Lan, Jie;Yu, Qigui
人类免疫缺陷病毒1型（HIV-1）通过将补体激活的宿主调节因子（RCA）整合到其包膜中来逃避补体介导的裂解（CML）。CD 59是RCA的一个关键成员，以保护免受CML的水平并入HIV-1病毒体。由于CD 59是一种糖基磷脂酰肌醇锚定蛋白（GPI-AP），我们使用GPI锚缺陷Jurkat细胞（Jurkat-7），表达细胞内CD 59，但不表达表面CD 59，研究CD 59掺入HIV-1病毒粒子的分子机制和宿主蛋白在病毒复制中的作用。与Jurkat细胞相比，Jurkat-7细胞对HIV-1复制的支持性较低，对CML更敏感。Jurkat-7细胞表现出与Jurkat细胞相似的HIV-1结合和进入能力，但对病毒RNA和DNA生物合成的支持性较低，因为感染的Jurkat-7细胞产生的HIV-1 RNA和DNA量减少。从Jurkat-7细胞产生的HIV-1病毒粒子是CD 59阴性的，这表明病毒粒子从细胞膜而不是细胞内区室获得CD 59，并且可能是其他宿主蛋白。结果表明，CD 59阴性病毒粒子对CML敏感。引人注目的是，这些病毒体表现出降低的病毒结合活性，感染性较低，这意味着GPI-AP在确保HIV-1颗粒的完整性方面也很重要。PIG-A基因的瞬时表达恢复了Jurkat-7细胞表面上的CD 59表达。在HIV-1感染后，恢复的CD 59与病毒包膜糖蛋白gp 120/gp 41共定位在脂筏内，这与感染的Jurkat细胞上的相同。因此，HIV-1病毒体从细胞表面获得RCA，可能是脂筏，以逃避CML并确保病毒感染性。
Human immunodeficiency virus type 1 (HIV-1) escapes complement-mediated lysis (CML) by incorporating host regulators of complement activation (RCA) into its envelope. CD59, a key member of RCA, is incorporated into HIV-1 virions at levels that protect against CML. Since CD59 is a glycosylphosphatidylinositol-anchored protein (GPI-AP), we used GPI anchor-deficient Jurkat cells (Jurkat-7) that express intracellular CD59, but not surface CD59, to study the molecular mechanisms underlying CD59 incorporation into HIV-1 virions and the role of host proteins in virus replication. Compared to Jurkat cells, Jurkat-7 cells were less supportive to HIV-1 replication and more sensitive to CML. Jurkat-7 cells exhibited similar capacities of HIV-1 binding and entry to Jurkat cells, but were less supportive to viral RNA and DNA biosynthesis as infected Jurkat-7 cells produced reduced amounts of HIV-1 RNA and DNA. HIV-1 virions produced from Jurkat-7 cells were CD59 negative, suggesting that viral particles acquire CD59, and probably other host proteins, from the cell membrane rather than intracellular compartments. As a result, CD59-negative virions were sensitive to CML. Strikingly, these virions exhibited reduced activity of virus binding and were less infectious, implicating that GPI-APs may be also important in ensuring the integrity of HIV-1 particles. Transient expression of the PIG-A gene restored CD59 expression on the surface of Jurkat-7 cells. After HIV-1 infection, the restored CD59 was colocalized with viral envelope glycoprotein gp120/gp41 within lipid rafts, which is identical to that on infected Jurkat cells. Thus, HIV-1 virions acquire RCA from the cell surface, likely lipid rafts, to escape CML and ensure viral infectivity.