Abstract：
Due to the high mutation rate of influenza virus and the rapid increase of drug resistance, it is imperative to discover host-targeting antiviral agents with broad-spectrum antiviral activity. Considering the discrepancy between the urgent demand of antiviral drugs during an influenza pandemic and the long-term process of drug discovery and development, it is feasible to explore host-based antiviral agents and strategies from antiviral drugs on the market. In the current study, the antiviral mechanism of arbidol (ARB), a broad-spectrum antiviral drug with potent activity at early stages of viral replication, was investigated from the aspect of hemagglutinin (HA) receptors of host cells. N-glycans that act as the potential binding receptors of HA on 16-human bronchial epithelial (16-HBE) cells were comprehensively profiled for the first time by using an in-depth glycomic approach based on TiO2-PGC chip-Q-TOF MS. Their relative levels upon the treatment of ARB and virus were carefully examined by employing an ultra-high sensitive qualitative method based on Chip LC-QQQ MS, showing that ARB treatment led to significant and extensive decrease of sialic acid (SA)-linked N-glycans (SA receptors), and thereby impaired the virus utilization on SA receptors for rolling and entry. The SA-decreasing effect of ARB was demonstrated to result from its inhibitory effect on sialyltransferases (ST), ST3GAL4 and ST6GAL1 of 16-HBE cells. Silence of STs, natural ST inhibitors, as well as sialidase treatment of 16-HBE cells, resulted in similar potent antiviral activity, whereas ST-inducing agent led to the diminished antiviral effect of ARB. These observations collectively suggesting the involvement of ST inhibition in the antiviral effect of ARB. IMPORTANCE This study revealed, for the first time, that ST inhibition and the resulted destruction of SA receptors of host cells may be an underlying mechanism for the antiviral activity of ARB. ST inhibition has been proposed as a novel host-targeting antiviral approach recently and several compounds are currently under exploration. ARB is the first antiviral drug on the market that was found to possess ST inhibiting function. This will provide crucial evidence for the clinical usages of ARB, such as in combination with neuraminidase (NA) inhibitors to exert optimized antiviral effect, etc. More importantly, as an agent that can inhibit the expression of STs, ARB can serve as a novel lead compound for the discovery and development of host-targeting antiviral drugs.
摘要：
由于流感病毒的高突变率和耐药性的迅速增加，发现具有广谱抗病毒活性的宿主靶向抗病毒药物势在必行。考虑到流感大流行期间对抗病毒药物的迫切需求与药物发现和开发的长期过程之间的差异，从市场上的抗病毒药物中探索基于宿主的抗病毒药物和策略是可行的。在目前的研究中,阿比多尔（ARB）的抗病毒机制，在病毒复制的早期阶段具有有效活性的广谱抗病毒药物，从宿主细胞的血凝素（HA）受体方面进行了研究。通过使用基于TiO2-PGC芯片-Q-TOFMS的深入糖漫学方法，首次全面分析了16人支气管上皮（16-HBE）细胞上HA的潜在结合受体的N-聚糖。通过采用基于ChipLC-QQQMS的超高灵敏度定性方法，仔细检查了它们在ARB和病毒治疗时的相对水平，表明ARB治疗导致唾液酸（SA）连接的N-聚糖（SA受体）的显着和广泛的减少，从而损害了病毒在SA受体上的滚动和进入。ARB的SA降低作用被证明是由于其对唾液酸转移酶（ST）的抑制作用，16-HBE细胞的ST3GAL4和ST6GAL1。STS的沉默，天然ST抑制剂，以及唾液酸酶处理16-HBE细胞，导致类似的有效抗病毒活性，而ST诱导剂导致ARB的抗病毒作用减弱。这些观察结果共同表明ST抑制参与ARB的抗病毒作用。重要性这项研究揭示了,第一次,ST抑制和导致的宿主细胞SA受体的破坏可能是ARB抗病毒活性的潜在机制。最近，ST抑制已被提出作为一种新型的宿主靶向抗病毒方法，目前正在探索几种化合物。ARB是市场上第一个被发现具有ST抑制功能的抗病毒药物。这将为ARB的临床使用提供重要证据，例如与神经氨酸酶（NA）抑制剂组合以发挥最佳的抗病毒作用，等。更重要的是,作为一种可以抑制STs表达的试剂，ARB可以作为发现和开发宿主靶向抗病毒药物的新型先导化合物。
