Imaging analysis of influenza virus behavior

流感病毒应该内吞以感染宿主细胞。由于内吞过程发生在细胞表面的特定区域，如包被的凹坑，附着在细胞表面的流感病毒需要移动到内吞区域。然而，病毒没有任何特定的机械来移动。病毒是如何进入内吞体区的？我们假设病毒颗粒通过病毒血凝素(HA)与其受体唾液酸聚糖之间的结合而在细胞表面一步一步地移动。为了证明病毒的运动性，我们使用全内反射荧光显微镜在涂有胎球蛋白的玻璃片上监测了流感病毒Mac11重组体(H3N2)的荧光标记，以模拟细胞表面。病毒在表面以0.2~1.5μm的不同步长不连续运动，神经氨酸酶抑制剂扎那米韦阻止病毒运动。根据这些结果，我们得出结论，流感病毒在含有病毒受体的表面上具有潜在的运动性，NA对病毒的移动是必不可少的。

Influenza viruses should be endocytosed to infect host cells. Since endocytic processes occur in specialized regions of a cell surface such as the coated pits, influenza viruses that attach to cell surfaces need to move to the endocytic regions. However, the virus dose not have any specific machinery to move. How does the virus access to the endocytic regions? We hypothesized that the virus particle moves step by step on a cell surface by exchanging bindings between viral hemagglutinin (HA) and its receptor, sialoglycan. To demonstrate the viral motility, we monitored a fluorescence-labeled influenza virus MAC11 reassortant (H3N2) on a glass coverslip coated with fetuin to mimic a cell surface, using a total internal reflection fluorescence microscope. The viruses moved discontinuously on the surface with various steps of 0.2-1.5μm. Moreover, neuraminidase inhibitor (zanamivir) prevented the virus moving. From these results, we conclude that an influenza virus has a potential motility on a surface containing the virus receptors and that NA is essential for the virus to move.