Ferreira Laura, Villar Enrique, Muñoz-Barroso Isabel
Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Edificio Departamental Lab. 108, Plaza Doctores de la Reina s/n, 37007 Salamanca, Spain.
Int J Biochem Cell Biol. 2004 Nov;36(11):2344-56. doi: 10.1016/j.biocel.2004.05.011.
The interaction of enveloped viruses with cell surface receptors is the first step in the viral cycle and an important determinant of viral host range. Although it is established that the paramyxovirus Newcastle Disease Virus binds to sialic acid-containing glycoconjugates the exact nature of the receptors has not yet been determined. Accordingly, here we attempted to characterize the cellular receptors for Newcastle disease virus. Treatment of cells with tunicamycin, an inhibitor of protein N-glycosylation, blocked fusion and infectivity, while the inhibitor of O-glycosylation benzyl-N-acetyl-alpha-D-galactosamide had no effect. Additionally, the inhibitor of glycolipid biosynthesis 1-phenyl-2-hexadecanoylamino-3-morpholino-1-propanol blocked viral fusion and infectivity. These results suggest that N-linked glycoproteins and glycolipids would be involved in viral entry but not O-linked glycoproteins. The ganglioside content of COS-7 cells was analyzed showing that GD1a was the major ganglioside component; the presence of GM1, GM2 and GM3 was also established. In a thin-layer chromatographic binding assay, we analyzed the binding of the virus to different gangliosides, detecting the interaction with monosialogangliosides such as GM3, GM2 and GM1; disialogangliosides such as GD1a and GD1b, and trisialogangliosides such as GT1b. Unlike with other viruses, our results seem to point to the absence of a specific pattern of gangliosides that interact with Newcastle disease virus. In conclusion, our results suggest that Newcastle disease virus requires different sialic acid-containing compounds, gangliosides and glycoproteins for entry into the target cell. We propose that gangliosides would act as primary receptors while N-linked glycoproteins would function as the second receptor critical for viral entry.
包膜病毒与细胞表面受体的相互作用是病毒循环的第一步，也是病毒宿主范围的重要决定因素。尽管已经确定副粘病毒新城疫病毒与含唾液酸的糖缀合物结合，但其受体的确切性质尚未确定。因此，我们在此试图对新城疫病毒的细胞受体进行表征。用蛋白质N-糖基化抑制剂衣霉素处理细胞可阻断融合和感染性，而O-糖基化抑制剂苄基-N-乙酰-α-D-半乳糖酰胺则没有效果。此外，糖脂生物合成抑制剂1-苯基-2-十六烷酰氨基-3-吗啉代-1-丙醇可阻断病毒融合和感染性。这些结果表明，N-连接糖蛋白和糖脂参与病毒进入，但O-连接糖蛋白不参与。对COS-7细胞的神经节苷脂含量进行分析，结果显示GD1a是主要的神经节苷脂成分；同时也确定了GM1、GM2和GM3的存在。在薄层层析结合试验中，我们分析了病毒与不同神经节苷脂的结合情况，检测到病毒与单唾液酸神经节苷脂如GM3、GM2和GM1；双唾液酸神经节苷脂如GD1a和GD1b；以及三唾液酸神经节苷脂如GT1b之间的相互作用。与其他病毒不同，我们的结果似乎表明不存在与新城疫病毒相互作用的特定神经节苷脂模式。总之，我们的结果表明，新城疫病毒进入靶细胞需要不同的含唾液酸化合物、神经节苷脂和糖蛋白。我们提出，神经节苷脂将作为主要受体，而N-连接糖蛋白将作为对病毒进入至关重要的第二受体发挥作用。
