Puri A, Morris S J, Jones P, Ryan M, Blumenthal R
Section on Membrane Structure and Function, NCI/NIH, Bethesda, Maryland 20892-1350, USA.
Virology. 1996 May 1;219(1):262-7. doi: 10.1006/viro.1996.0244.
It has been shown that human CD4 expressed in nonhuman cells does not support HIV-1 entry into those cells and that components from human cells in addition to CD4 are required to overcome the block. We have used human red blood cells (huRBC) as a source for the accessory components since their membrane composition is less complex than that of nucleated cells and they are well characterized. Components were transferred by fusion of huRBC to nonhuman CD4(+) cells mediated by influenza hemagglutinin or polyethylene glycol. The RBC-modified nonhuman CD4(+) cells were labeled with fluorescent markers and incubated with gp 120-gp41-expressing cells labeled with a different fluorescent probe. Fusion between RBC- modified nonhuman CD4(+) cells and gp 120--gp41-expressing cells was quantified by fluorescence video microscopy. Human erythrocyte components transferred to nonhuman CD4+ cells conferred HIV-1 envelope glycoprotein-mediated fusion susceptibility to those cells. The fusion was enhanced by pretreatment of the erythrocytes for 10 min at 56 degrees. No gp 120--gp41-mediated fusion was observed when components from nonhuman RBC were transferred to nonhuman CD4+ cells. Human cell lines with pre-RBC characteristics (K562-CD4) also supported HIV-1 envelope glycoprotein-mediated fusion.
研究表明，在非人类细胞中表达的人类CD4不支持HIV-1进入这些细胞，并且除了CD4之外还需要来自人类细胞的成分来克服这一障碍。我们使用人类红细胞（huRBC）作为辅助成分的来源，因为它们的膜组成比有核细胞的膜组成更简单，并且它们具有很好的特征。通过流感血凝素或聚乙二醇介导的huRBC与非人类CD4(+)细胞的融合来转移成分。用荧光标记物标记经红细胞修饰的非人类CD4(+)细胞，并与用不同荧光探针标记的表达gp 120-gp41的细胞一起孵育。通过荧光视频显微镜对经红细胞修饰的非人类CD4(+)细胞与表达gp 120-gp41的细胞之间的融合进行定量。转移到非人类CD4+细胞的人类红细胞成分赋予这些细胞HIV-1包膜糖蛋白介导的融合敏感性。在56℃下将红细胞预处理10分钟可增强融合。当将来自非人类红细胞的成分转移到非人类CD4+细胞时，未观察到gp 120-gp41介导的融合。具有红细胞前体特征的人类细胞系（K562-CD4）也支持HIV-1包膜糖蛋白介导的融合。
