Functional characterization of HIV-1 Nef mutants in the context of viral infection
Functional characterization of HIV-1 Nef mutants in the context of viral infection
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DOI：
10.1016/j.virol.2006.03.044
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发表时间：
2006-08-01
期刊：
影响因子：
3.7
通讯作者：
Kraeusslich, Hans-Georg
中科院分区：
文献类型：
--
作者：
Fackler, Oliver T.;Moris, Arnaud;Kraeusslich, Hans-Georg
Nef是HIV-1的重要致病因子，具有多种效应功能。我们已经设计了一个广泛的同基因病毒编码定义的突变体的HIV-1（SF 2）Nef和生产性HIV-1感染的背景下，分析其生物活性。亚细胞定位，病毒粒子掺入，下调细胞表面的CD 4和MHC-1，增强病毒粒子的感染性和促进HIV在原代人T淋巴细胞中的复制的分析大多证实了以前报道的Nef决定簇的映射后，孤立的表达Nef。然而，在CD 4的下调，感染性增强和病毒体掺入的Nef变体（A 1239）缺乏的细胞激酶复合物的结合所需的双端螺旋和协会的Nef与MHC-1/AP-1的下调活性降低建议这种N-末端基序的新的作用。Nef的SH 3结合基序部分是感染性增强和复制所需的，但不是受体下调所需的。与以前使用其他Nef等位基因获得的结果相反，非肉豆蔻酰化SF 2-Nef在HIV感染期间表达时仅部分缺陷，并且存在于HIV-1颗粒中。重要的是，Nef掺入HIV-1病毒体中对于任何测试的Nef活性都不是必需的。总之，这项研究提供了一个广泛的表征和映射的HIV感染的细胞中的多种Nef活动。结果强调，多种活动管理Nef对HIV复制的影响，并反对病毒粒子掺入Nef的活性作为致病因子的作用。(c)2006爱思唯尔公司All rights reserved.
Nef is an important pathogenesis factor of HIV-1 with a multitude of effector functions. We have designed a broad panel of isogenic viruses encoding defined mutants of HIV-1(SF2) Nef and analyzed their biological activity in the context of productive HIV-1 infection. Analysis of subcellular localization, virion incorporation, downregulation of cell surface CD4 and MHC-1, enhancement of virion infectivity and facilitation of HIV replication in primary human T lymphocytes mostly confirmed the mapping of Nef determinants previously reported upon isolated expression of Nef. However, reduced activity in downregulation of CD4, infectivity enhancement and virion incorporation of a Nef variant (A 1239) lacking an amphipatic helix required for binding of a cellular kinase complex and the association of Nef with MHC-1/AP-1 suggested a novel role of this N-terminal motif. The SH3 binding motif of Nef was partially required for infectivity enhancement and replication but not for receptor downmodulation. In contrast to previous results obtained using other Nef alleles, non-myristoylated SF2-Nef was only partly defective when expressed during HIV infection and was present in HIV-1 particles. Importantly, incorporation of Nef into HIV-1 virions was not required for any of the tested Nef activities. Altogether, this study provides a broad characterization and mapping of multiple Nef activities in HIV-infected cells. The results emphasize that multiple activities govern Nef's effects on HIV replication and argue against a role of virion incorporation for Nef's activity as pathogenicity factor. (c) 2006 Elsevier Inc. All rights reserved.