MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
J Virol. 2013 Feb;87(3):1649-57. doi: 10.1128/JVI.02201-12. Epub 2012 Nov 21.
Chronic infection by hepatitis C virus (HCV) is a cause of the global burden of liver diseases. HCV entry into hepatocytes is a complicated and multistep process that represents a promising target for antiviral intervention. The recently reported amphipathic α-helical virucidal peptide (C5A) from the HCV NS5A protein suggests a new category of antiviral drug candidates. In this study, to identify C5A-like HCV inhibitors, synthetic peptides derived from the C5A-corresponding NS5 protein region of selected Flaviviridae viruses were evaluated for their anti-HCV activities. A peptide from GB virus A (GBV-A), but not other flaviviruses, demonstrated an inhibitory effect on HCV infection. Through a series of sequence optimizations and modifications of the peptide helicity and hydrophobicity, we obtained a peptide designated GBVA10-9 with highly potent anti-HCV activity. GBVA10-9 suppressed infection with both cell culture-derived and pseudotyped HCV in vitro, and the 50% cell culture inhibitory concentration ranged from 20 nM to 160 nM, depending on the genotypic origin of the envelope proteins. GBVA10-9 had no detectable effects on either HCV attachment to Huh7.5.1 cells or viral RNA replication. No virucidal activity was found with GBVA10-9, suggesting an action mechanism distinct from that of C5A. The inhibitory effect of GBVA10-9 appeared to occur at the postbinding step during viral entry. Taken together, the results with GBVA10-9 demonstrated a potent activity for blocking HCV entry that might be used in combination with other antivirals directly targeting virus-encoded enzymes. Furthermore, GBVA10-9 also provides a novel tool to dissect the detailed mechanisms of HCV entry.
慢性丙型肝炎病毒 (HCV) 感染是全球肝脏疾病负担的一个原因。HCV 进入肝细胞是一个复杂的多步骤过程，是抗病毒干预的一个有前途的靶点。最近报道的 HCV NS5A 蛋白中的两亲性α螺旋溶细胞肽 (C5A) 提示了一类新的抗病毒药物候选物。在这项研究中，为了鉴定 C5A 样 HCV 抑制剂，评估了源自选定黄病毒科病毒的 C5A 对应的 NS5 蛋白区域的合成肽的抗 HCV 活性。来自 GB 病毒 A (GBV-A) 的肽，但不是其他黄病毒，显示出对 HCV 感染的抑制作用。通过对肽的螺旋性和疏水性进行一系列序列优化和修饰，我们得到了一种被命名为 GBVA10-9 的肽，它具有很强的抗 HCV 活性。GBVA10-9 在体外抑制细胞培养和假型 HCV 的感染，50%细胞培养抑制浓度范围为 20 nM 至 160 nM，具体取决于包膜蛋白的基因型来源。GBVA10-9 对 HCV 附着到 Huh7.5.1 细胞或病毒 RNA 复制没有检测到的影响。GBVA10-9 没有发现病毒溶解活性，这表明其作用机制与 C5A 不同。GBVA10-9 的抑制作用似乎发生在病毒进入的结合后步骤。总的来说，GBVA10-9 的结果表明其具有阻断 HCV 进入的强大活性，可与直接针对病毒编码酶的其他抗病毒药物联合使用。此外，GBVA10-9 还提供了一种新的工具来剖析 HCV 进入的详细机制。
