Lu Gaofeng, Villa Juan Antonio, Donlin Maureen J, Edwards Tiffany C, Cheng Xiaohong, Heier Richard F, Meyers Marvin J, Tavis John E
Department of Molecular Microbiology and Immunology and Saint Louis University Liver Center, Saint Louis University School of Medicine, St. Louis, MO, USA; Department of Gastroenterology, The Second Affiliated Hospital, Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
Department of Molecular Microbiology and Immunology and Saint Louis University Liver Center, Saint Louis University School of Medicine, St. Louis, MO, USA.
Antiviral Res. 2016 Nov;135:24-30. doi: 10.1016/j.antiviral.2016.09.009. Epub 2016 Sep 28.
Hepatitis B virus (HBV) causes hepatitis, cirrhosis, liver failure, and liver cancer, but the current therapies that employ either nucelos(t)ide analogs or (pegylated)interferon α do not clear the infection in the large majority of patients. Inhibitors of the HBV ribonuclease H (RNaseH) that are being developed with the goal of producing anti-HBV drugs are promising candidates for use in combination with the nucleos(t)ide analogs to improve therapeutic efficacy. HBV is genetically very diverse, with at least 8 genotypes that differ by ≥8% at the sequence level. This diversity is reflected in the viral RNaseH enzyme, raising the possibility that divergent HBV genotypes or isolates may have varying sensitivity to RNaseH inhibitors. To evaluate this possibility, we expressed and purified 18 patient-derived RNaseHs from genotypes B, C, and D. Basal RNaseH activity and sensitivity to three novel RNaseH inhibitors from three different chemotypes were assessed. We also evaluated four consensus HBV RNaseHs to determine if such sequences would be suitable for use in antiviral drug screening. The patient-derived enzymes varied by over 10-fold in their basal RNaseH activities, but they were equivalently sensitive to each of the three inhibitors. Similarly, all four consensus HBV RNaseH enzymes were active and were equally sensitive to an RNaseH inhibitor. These data indicate that a wide range of RNaseH sequences would be suitable for use in antiviral drug screening, and that genotype- or isolate-specific genetic variations are unlikely to present a barrier during antiviral drug development against the HBV RNaseH.
乙型肝炎病毒（HBV）可导致肝炎、肝硬化、肝衰竭和肝癌，但目前使用核苷酸类似物或（聚乙二醇化）干扰素α的治疗方法并不能使绝大多数患者清除感染。正在研发的以生产抗HBV药物为目标的HBV核糖核酸酶H（RNaseH）抑制剂有望与核苷酸类似物联合使用，以提高治疗效果。HBV在基因上具有高度多样性，至少有8种基因型，在序列水平上差异≥8%。这种多样性反映在病毒RNaseH酶中，这增加了不同的HBV基因型或分离株对RNaseH抑制剂可能具有不同敏感性的可能性。为了评估这种可能性，我们表达并纯化了来自B、C和D基因型的18种患者来源的RNaseH。评估了基础RNaseH活性以及对来自三种不同化学类型的三种新型RNaseH抑制剂的敏感性。我们还评估了四种HBV RNaseH共有序列，以确定这些序列是否适用于抗病毒药物筛选。患者来源的酶的基础RNaseH活性相差超过10倍，但它们对三种抑制剂中的每一种的敏感性相同。同样，所有四种HBV RNaseH共有序列酶都有活性，并且对一种RNaseH抑制剂的敏感性相同。这些数据表明，广泛的RNaseH序列适用于抗病毒药物筛选，并且基因型或分离株特异性的基因变异在针对HBV RNaseH的抗病毒药物开发过程中不太可能成为障碍。
