Department of Infectious Diseases and Immunology, Virology Division, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Antimicrob Agents Chemother. 2013 Oct;57(10):4971-81. doi: 10.1128/AAC.01175-13. Epub 2013 Jul 29.
Despite their high clinical and socioeconomic impacts, there is currently no approved antiviral therapy for the prophylaxis or treatment of enterovirus infections. Here we report on a novel inhibitor of enterovirus replication, compound 1, 2-fluoro-4-(2-methyl-8-(3-(methylsulfonyl)benzylamino)imidazo[1,2-a]pyrazin-3-yl)phenol. This compound exhibited a broad spectrum of antiviral activity, as it inhibited all tested species of enteroviruses and rhinoviruses, with 50% effective concentrations ranging between 4 and 71 nM. After a lengthy resistance selection process, coxsackievirus mutants resistant to compound 1 were isolated that carried substitutions in their 3A protein. Remarkably, the same substitutions were recently shown to provide resistance to inhibitors of phosphatidylinositol 4-kinase IIIβ (PI4KIIIβ), a lipid kinase that is essential for enterovirus replication, suggesting that compound 1 may also target this host factor. Accordingly, compound 1 directly inhibited PI4KIIIβ in an in vitro kinase activity assay. Furthermore, the compound strongly reduced the PI 4-phosphate levels of the Golgi complex in cells. Rescue of coxsackievirus replication in the presence of compound 1 by a mutant PI4KIIIβ carrying a substitution in its ATP-binding pocket revealed that the compound directly binds the kinase at this site. Finally, we determined that an analogue of compound 1, 3-(3-fluoro-4-methoxyphenyl)-2-methyl-N-(pyridin-4-ylmethyl)imidazo[1,2-a]pyrazin-8-amine, is well tolerated in mice and has a dose-dependent protective activity in a coxsackievirus serotype B4-induced pancreatitis model.
尽管肠病毒感染具有很高的临床和社会经济学影响，但目前尚无批准的抗病毒疗法可用于预防或治疗肠病毒感染。在这里，我们报告了一种新型肠病毒复制抑制剂，化合物 1，2-氟-4-（2-甲基-8-（3-（甲基磺酰基）苄基氨基）咪唑并[1,2-a]吡嗪-3-基）苯酚。该化合物表现出广谱的抗病毒活性，因为它抑制了所有测试的肠病毒和鼻病毒，其 50%有效浓度范围在 4 到 71 nM 之间。经过长时间的耐药性选择过程，分离出对化合物 1 耐药的柯萨奇病毒突变体，这些突变体在其 3A 蛋白中携带取代。值得注意的是，最近发现这些相同的取代可提供对磷脂酰肌醇 4-激酶 IIIβ（PI4KIIIβ）抑制剂的耐药性，PI4KIIIβ 是一种对肠病毒复制至关重要的脂质激酶，这表明化合物 1 也可能靶向该宿主因子。因此，化合物 1 在体外激酶活性测定中直接抑制了 PI4KIIIβ。此外，该化合物强烈降低了细胞中高尔基复合体的 PI 4-磷酸水平。在存在化合物 1 的情况下，携带其 ATP 结合口袋取代的突变型 PI4KIIIβ 拯救柯萨奇病毒复制表明该化合物直接在该位点结合激酶。最后，我们确定了化合物 1 的一种类似物，3-（3-氟-4-甲氧基苯基）-2-甲基-N-（吡啶-4-基甲基）咪唑并[1,2-a]吡嗪-8-胺，在小鼠中具有良好的耐受性，并在柯萨奇病毒 B4 诱导的胰腺炎模型中具有剂量依赖性的保护活性。
