Association of Nef with p21-activated kinase 2 is dispensable for efficient human immunodeficiency virus type 1 replication and cytopathicity in ex vivo-infected human lymphoid tissue.
Association of Nef with p21-activated kinase 2 is dispensable for efficient human immunodeficiency virus type 1 replication and cytopathicity in ex vivo-infected human lymphoid tissue.
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Nef 与 p21 激活激酶 2 的结合对于 1 型人类免疫缺陷病毒在离体感染的人淋巴组织中的有效复制和细胞病变来说是可有可无的。
DOI：
10.1128/jvi.01436-07
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发表时间：
2007
影响因子：
5.4
通讯作者：
Kirchhoff,Frank
中科院分区：
文献类型：
--
作者：
Schindler,Michael;Rajan,Devi;Specht,Anke;Ritter,Carolin;Pulkkinen,Kati;Saksela,Kalle;Kirchhoff,Frank
人类免疫缺陷病毒 1 型 (HIV-1) Nef 蛋白与 p21 激活激酶 2 (PAK2) 的相互作用已被认为在 T 细胞激活、病毒复制、细胞凋亡和艾滋病进展中发挥作用。然而，这些假设是基于使用多种功能受损的 Nef 突变体获得的结果。最近，有报道称Nef残基F191特异性参与PAK2结合。然而，这些研究只调查了有限数量的 Nef 活性。为了进一步评估 F191 在 Nef 功能中的作用并阐明 Nef-PAK2 相互作用的生物学相关性，我们对携带 F191H 和 F191R 突变的 HIV-1 Nef 突变体进行了全面分析。我们发现 F191H 突变减少了 Nef 与 PAK2 的关联，而 F191R 突变则破坏了 Nef 与 PAK2 的关联。两种突变体均上调主要组织相容性复合体 II (MHC-II) 相关的不变链，并下调 CD4、MHC-I 和 CD28，但后者的效率降低。此外，F191H/R 的变化既不影响白细胞介素 2 受体的表达水平和 HIV-1 感染的原代 T 细胞的凋亡，也不减少 Nef 介导的 NFAT 诱导。出乎意料的是，F191H 变化显着减少，F191R 突变破坏了 Nef 在 P4-CCR5 指示细胞中增强病毒粒子感染性的能力，但在 TZM-bl 细胞或外周血单核细胞中则没有。最重要的是，所有 HIV-1 Nef 突变体都能有效复制，并在离体感染的人淋巴组织中引起 CD4+T 细胞耗竭。总而言之，我们的数据表明 Nef 与 PAK2 的相互作用在 T 细胞激活、病毒复制和细胞凋亡中并不起主要作用。
Interaction of the human immunodeficiency virus type 1 (HIV-1) Nef protein with p21-activated kinase 2 (PAK2) has been proposed to play a role in T-cell activation, viral replication, apoptosis, and progression to AIDS. However, these hypotheses were based on results obtained using Nef mutants impaired in multiple functions. Recently, it was reported that Nef residue F191 is specifically involved in PAK2 binding. However, only a limited number of Nef activities were investigated in these studies. To further evaluate the role of F191 in Nef function and to elucidate the biological relevance of Nef-PAK2 interaction, we performed a comprehensive analysis of HIV-1 Nef mutants carrying F191H and F191R mutations. We found that the F191H mutation reduces and the F191R mutation disrupts the association of Nef with PAK2. Both mutants upregulated the major histocompatibility complex II (MHC-II)-associated invariant chain and downregulated CD4, MHC-I, and CD28, although with reduced efficiency for the latter. Furthermore, the F191H/R changes neither affected the levels of interleukin-2 receptor expression and apoptosis of HIV-1-infected primary T cells nor reduced Nef-mediated induction of NFAT. Unexpectedly, the F191H change markedly reduced and the F191R mutation disrupted the ability of Nef to enhance virion infectivity in P4-CCR5 indicator cells but not in TZM-bl cells or peripheral blood mononuclear cells. Most importantly, all HIV-1 Nef mutants replicated efficiently and caused CD4+T-cell depletion in ex vivo-infected human lymphoid tissue. Altogether, our data show that the interaction of Nef with PAK2 does not play a major role in T-cell activation, viral replication, and apoptosis.