Kinetic analysis of the influenza A virus HA/NA balance reveals contribution of NA to virus-receptor binding and NA-dependent rolling on receptor-containing surfaces
Kinetic analysis of the influenza A virus HA/NA balance reveals contribution of NA to virus-receptor binding and NA-dependent rolling on receptor-containing surfaces
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DOI：
10.1371/journal.ppat.1007233
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发表时间：
2018-08-01
期刊：
影响因子：
6.7
通讯作者：
de Haan, Cornelis A. M.
中科院分区：
文献类型：
--
作者：
Guo, Hongbo;Rabouw, Huib;de Haan, Cornelis A. M.
甲型流感病毒（IAV）与唾液酸（SIA）受体的相互作用决定了病毒适应性和宿主嗜性。与粘液诱饵受体和上皮宿主细胞上的受体的结合由受体结合血凝素（HA）、受体破坏神经氨酸酶（NA）和复杂的体内受体库决定。这些多价病毒-受体相互作用的关键但知之甚少的动力学不能使用平衡结合模型和终点结合测定法进行适当分析。在这项研究中，使用生物层干涉分析揭示了几乎不可逆的性质，IAV结合到表面涂有合成的唾液酸苷或工程sialoglycoproteins在NA活性的情况下。除了HA，NA被证明能够有助于初始结合率，同时具有催化活性。病毒受体结合反过来又有助于受体裂解NA。多种低亲和力HA-SIA相互作用导致总体上极高的亲合力，但也允许动态结合模式，其中NA活性驱动病毒颗粒在受体表面上滚动。由于滚动IAV颗粒的NA活性，病毒解离仅在完整受体表面的受体密度充分降低后发生。结果表明，在体内IAV颗粒，降落在粘液层后，连续驻留在受体结合状态，同时滚动通过粘液层和上皮细胞表面上的HA-NA-受体平衡驱动。定量BLI分析使得能够对这种平衡进行功能检查，这种平衡支配这种动态和能动的相互作用，预期这种动态和能动的相互作用对于IAV穿透粘液层和随后的细胞感染至关重要，但也可能被携带受体破坏酶以及受体结合蛋白的其他包膜病毒感染。
Interactions of influenza A virus (IAV) with sialic acid (SIA) receptors determine viral fitness and host tropism. Binding to mucus decoy receptors and receptors on epithelial host cells is determined by a receptor-binding hemagglutinin (HA), a receptor-destroying neuraminidase (NA) and a complex in vivo receptor-repertoire. The crucial but poorly understood dynamics of these multivalent virus-receptor interactions cannot be properly analyzed using equilibrium binding models and endpoint binding assays. In this study, the use of biolayer interferometric analysis revealed the virtually irreversible nature of IAV binding to surfaces coated with synthetic sialosides or engineered sialoglycoproteins in the absence of NA activity. In addition to HA, NA was shown to be able to contribute to the initial binding rate while catalytically active. Virus-receptor binding in turn contributed to receptor cleavage by NA. Multiple low-affinity HA-SIA interactions resulted in overall extremely high avidity but also permitted a dynamic binding mode, in which NA activity was driving rolling of virus particles over the receptor-surface. Virus dissociation only took place after receptor density of the complete receptor-surface was sufficiently decreased due to NA activity of rolling IAV particles. The results indicate that in vivo IAV particles, after landing on the mucus layer, reside continuously in a receptor-bound state while rolling through the mucus layer and over epithelial cell surfaces driven by the HA-NA-receptor balance. Quantitative BLI analysis enabled functional examination of this balance which governs this dynamic and motile interaction that is expected to be crucial for penetration of the mucus layer and subsequent infection of cells by IAV but likely also by other enveloped viruses carrying a receptor-destroying enzyme in addition to a receptor-binding protein.