Inhibition of HIV-1 endocytosis allows lipid mixing at the plasma membrane, but not complete fusion.
Inhibition of HIV-1 endocytosis allows lipid mixing at the plasma membrane, but not complete fusion.
复制标题
DOI：
10.1186/1742-4690-8-99
复制
发表时间：
2011-12-06
期刊：
影响因子：
3.3
通讯作者：
Melikyan GB
中科院分区：
文献类型：
--
作者：
de la Vega M;Marin M;Kondo N;Miyauchi K;Kim Y;Epand RF;Epand RM;Melikyan GB
我们最近提供的证据表明，HIV-1通过与内体融合进入HeLa衍生的TZM-b1和淋巴样CEMss细胞，而其与质膜的融合不超过脂质混合步骤。HIV-1融合在细胞表面的限制机制和/或帮助病毒从内体进入的因素仍不清楚。我们检查了HIV-1与一组靶细胞系以及与原代CD 4 + T细胞的融合。融合的动力学测量结合单个病毒的时间分辨成像进一步加强了HIV-1通过内吞作用和与内体融合进入细胞的概念。此外，我们试图故意重定向病毒融合到质膜，使用两种实验策略。首先，通过在降低的温度下将病毒与细胞预孵育以允许CD 4和辅助受体接合而不是病毒摄取或融合来同步融合反应。随后转变到生理温度触发了加速的病毒摄取，随后从内体进入，但不允许在细胞表面融合。第二，阻断HIV-1的内吞作用的小分子发动蛋白抑制剂，dynasore，导致转移的病毒脂质质膜没有任何可检测的释放到细胞质中的病毒内容。我们还发现，与病毒内化相比，需要更高浓度的dynasore来阻断HIV-内体融合。我们的结果进一步支持了HIV-1通过与内体融合进入不同细胞类型的观点。在脂质混合后阶段，HIV-1与质膜融合的阻断表明该膜不利于融合孔的形成和/或扩大。动力蛋白干扰病毒-内体融合的能力表明，动力蛋白可能参与HIV-1进入的两个不同步骤--胞吞作用和细胞内区室的融合。
We recently provided evidence that HIV-1 enters HeLa-derived TZM-bl and lymphoid CEMss cells by fusing with endosomes, whereas its fusion with the plasma membrane does not proceed beyond the lipid mixing step. The mechanism of restriction of HIV-1 fusion at the cell surface and/or the factors that aid the virus entry from endosomes remain unclear. We examined HIV-1 fusion with a panel of target cells lines and with primary CD4+ T cells. Kinetic measurements of fusion combined with time-resolved imaging of single viruses further reinforced the notion that HIV-1 enters the cells via endocytosis and fusion with endosomes. Furthermore, we attempted to deliberately redirect virus fusion to the plasma membrane, using two experimental strategies. First, the fusion reaction was synchronized by pre-incubating the viruses with cells at reduced temperature to allow CD4 and coreceptors engagement, but not the virus uptake or fusion. Subsequent shift to a physiological temperature triggered accelerated virus uptake followed by entry from endosomes, but did not permit fusion at the cell surface. Second, blocking HIV-1 endocytosis by a small-molecule dynamin inhibitor, dynasore, resulted in transfer of viral lipids to the plasma membrane without any detectable release of the viral content into the cytosol. We also found that a higher concentration of dynasore is required to block the HIV-endosome fusion compared to virus internalization. Our results further support the notion that HIV-1 enters disparate cell types through fusion with endosomes. The block of HIV-1 fusion with the plasma membrane at a post-lipid mixing stage shows that this membrane is not conducive to fusion pore formation and/or enlargement. The ability of dynasore to interfere with the virus-endosome fusion suggests that dynamin could be involved in two distinct steps of HIV-1 entry - endocytosis and fusion within intracellular compartments.
登录
查看更多内容
影响因子：
5.4
作者：
Guo, Jia;Wang, Weifeng;Wu, Yuntao
通讯作者：
Wu, Yuntao
影响因子：
4.8
作者：
Henderson HI;Hope TJ
通讯作者：
Hope TJ
影响因子：
5.4
作者：
Daecke, J;Fackler, OT;Kräusslich, HG
通讯作者：
Kräusslich, HG
影响因子：
5.4
作者：
Binley, JM;Cayanan, CS;Burton, DR
通讯作者：
Burton, DR
影响因子：
5.4
作者：
Fredericksen, BL;Wei, BL;Garcia, JV
通讯作者：
Garcia, JV