Institute of Virology, University of Erlangen-Nuremberg, Germany; Institute of Virology, Helmholtz Zentrum Munich, Germany.
Institute of Virology, University of Erlangen-Nuremberg, Germany.
Virology. 2014 Sep;464-465:375-384. doi: 10.1016/j.virol.2014.07.034. Epub 2014 Aug 9.
HIV-1 NL4-3 Vpu induces downregulation of cell surface CD155, a ligand for the DNAM-1 activating receptor of NK and CD8(+) T cells, to evade NK cell mediated immune response. Here we show that the conserved alanine residues at positions 10, 14 and 18 in the TM domain of Vpu are required for the efficient downregulation of cell surface CD155. In contrast, the CK-2 phosphorylation sites and the second α-helix in the cytoplasmic Vpu domain have no influence on the surface expression of CD155. Thus, compared to Vpu׳s effect on CD4, NTB-A and tetherin, the Vpu mediated downregulation of CD155 is an independent Vpu function. We finally show that in contrast to other lentiviral strains, only Vpu and Nef from HIV-1 M NL4-3 potently interfere with CD155 surface expression. Thus, Vpu seems to subvert NK cell responses against HIV-1 infected T cells by modulation of receptors necessary for NK cell activation.
HIV-1 NL4-3 Vpu 诱导细胞表面 CD155 的下调,CD155 是 NK 和 CD8(+) T 细胞的 DNAM-1 激活受体的配体,从而逃避 NK 细胞介导的免疫反应。在这里,我们表明 Vpu 的跨膜结构域中位置 10、14 和 18 的保守丙氨酸残基对于细胞表面 CD155 的有效下调是必需的。相比之下,CK-2 磷酸化位点和细胞质 Vpu 结构域中的第二个 α-螺旋对 CD155 的表面表达没有影响。因此,与 Vpu 对 CD4、NTB-A 和 tetherin 的影响相比,Vpu 介导的 CD155 下调是 Vpu 的一个独立功能。我们最后表明,与其他慢病毒株不同,只有 HIV-1 M NL4-3 的 Vpu 和 Nef 能够强烈干扰 CD155 的表面表达。因此,Vpu 似乎通过调节 NK 细胞激活所需的受体来颠覆针对 HIV-1 感染的 T 细胞的 NK 细胞反应。