Virion-liposome interactions identify a cholesterol-independent coronavirus entry stage.
Virion-liposome interactions identify a cholesterol-independent coronavirus entry stage.
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病毒粒子-脂质体相互作用确定了不依赖胆固醇的冠状病毒进入阶段。
DOI：
10.1007/978-0-387-33012-9_53
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发表时间：
2006
影响因子：
--
通讯作者：
Gallagher,ThomasM
中科院分区：
文献类型：
--
作者：
Boscarino,JosephA;Goletz,JeffreyM;Gallagher,ThomasM
Entry of enveloped viruses depends on several cellular components, including protein or carbohydrate receptors and oftentimes co-receptors that both bind viruses to cells and catalyze the initial stages of viral surface protein refolding. 1 Endocytosis is a common prerequisite to successful entry; both the acidic pH and the proteases of the endosome can create further structural changes in the viral proteins mediating cell receptor binding and virus-cell membrane fusion. 2 Finally, an appropriate lipid environment, often abundant in sterols, is also frequently necessary to achieve facile fusion of viral and cellular membranes. 3 In numerous seminal investigations, each of these steps has been dissected by blocking virus entry with mutant transgenes or with drugs that alter receptors or endosome or lipid environments. Although these are powerful approaches, the findings can be complicated when the transgenes or drugs create untoward pleiotropic changes in cellular functions. A complementary reductionist approach involves in vitro virus entry in which enveloped viruses are bound to and then fused into synthetic liposomes. 4 In these test-tube reactions, receptors, pH, proteases and liposome bilayer compositions can be precisely defined and freely altered in ways not achievable in living cells. Such systems are useful adjuncts to understanding the biochemistry of enveloped virus entry. In vitro virus-liposome binding assays have been recently developed for the murine coronaviruses. 5, 6 In these studies, purified MHV particles acquired hydrophobic character by incubation with soluble MHV receptors or by exposures to elevated pH, thus causing a small proportion of the virus population to associate with liposomes. We aimed to advance these studies by creating liposomes that more closely reflect authentic MHV-susceptible cells. To this end, we created synthetic liposomes containing nickelnitriloacetic acid (NiNTA) adducts on a fraction of lipid head groups. Soluble MHV receptors containing engineered polyhistidine tags could then be attached to the liposomes, thereby creating artificial targets for virus binding. These liposomes with
