KU Leuven, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Leuven, Belgium
KU Leuven, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Leuven, Belgium.
Antimicrob Agents Chemother. 2021 Feb 17;65(3). doi: 10.1128/AAC.01732-20.
Here, we report on the anti-influenza virus activity of the mannose-binding agents hybrid agglutinin (HHA) and agglutinin (GNA) and the (-acetylglucosamine) -specific agglutinin (UDA). These carbohydrate-binding agents (CBA) strongly inhibited various influenza A(H1N1), A(H3N2), and B viruses , with 50% effective concentration values ranging from 0.016 to 83 nM, generating selectivity indexes up to 125,000. Somewhat less activity was observed against A/Puerto Rico/8/34 and an A(H1N1)pdm09 strain. In time-of-addition experiments, these CBA lost their inhibitory activity when added 30 min postinfection (p.i.). Interference with virus entry processes was also evident from strong inhibition of virus-induced hemolysis at low pH. However, a direct effect on acid-induced refolding of the viral hemagglutinin (HA) was excluded by the tryptic digestion assay. Instead, HHA treatment of HA-expressing cells led to a significant reduction of plasma membrane mobility. Crosslinking of membrane glycoproteins, through interaction with HA, could also explain the inhibitory effect on the release of newly formed virions when HHA was added at 6 h p.i. These CBA presumably interact with one or more -glycans on the globular head of HA, since their absence led to reduced activity against mutant influenza B viruses and HHA-resistant A(H1N1) viruses. The latter condition emerged only after 33 cell culture passages in the continuous presence of HHA, and the A(H3N2) virus retained full sensitivity even after 50 passages. Thus, these CBA qualify as potent inhibitors of influenza A and B viruses with a pleiotropic mechanism of action and a high barrier for viral resistance.
在这里，我们报告了甘露糖结合剂杂凝集素（HHA）和凝集素（GNA）以及（N-乙酰葡萄糖胺）特异性凝集素（UDA）的抗流感病毒活性。这些碳水化合物结合剂（CBA）强烈抑制了各种甲型流感（H1N1）、A（H3N2）和 B 病毒，其 50%有效浓度值范围为 0.016 至 83 nM，产生的选择性指数高达 125,000。对 A/Puerto Rico/8/34 和 A（H1N1）pdm09 株的活性略低。在添加时间实验中，这些 CBA 在感染后 30 分钟添加时失去了抑制活性。病毒进入过程的干扰也很明显，因为低 pH 值下强烈抑制了病毒诱导的溶血。然而，通过胰蛋白酶消化测定排除了 CBA 对酸诱导的病毒血凝素（HA）重折叠的直接影响。相反，HHA 处理表达 HA 的细胞会导致质膜流动性显著降低。通过与 HA 相互作用交联膜糖蛋白也可以解释当 HHA 在感染后 6 小时添加时，对新形成的病毒粒子释放的抑制作用。这些 CBA 可能与 HA 球状头部的一个或多个β-聚糖相互作用，因为它们的缺失导致对突变型流感 B 病毒和 HHA 抗性 A（H1N1）病毒的活性降低。在后一种情况下，仅在持续存在 HHA 的情况下经过 33 个细胞培养传代后才出现，并且 A（H3N2）病毒即使经过 50 个传代后仍保持完全敏感。因此，这些 CBA 是甲型和乙型流感病毒的有效抑制剂，具有多种作用机制和高病毒耐药性屏障。
