Comprehensive screening of host proteins that suppress replication of HCV replicon

我们利用丙型肝炎病毒亚基因组复制模型和细胞培养模型对抑制丙型肝炎病毒复制的宿主蛋白进行了全面的筛选研究。(1)高通量筛选包含2,500种生物活性药物、多肽和化合物的文库：我们发现了52种抑制或增强丙型肝炎病毒复制的化合物(胃肠病学，2006)。(2)针对分子伴侣和亲环素的抗病毒疗法的建立：我们已经报道了环孢菌素A通过阻断环胞菌素A、B和C的作用来抑制丙型肝炎病毒的复制。在本研究中，我们接下来通过细菌双杂交系统筛选与环孢菌素相互作用的宿主蛋白，并鉴定了包括G蛋白偶联蛋白在内的几种蛋白。我们目前正在进行研究以了解这些蛋白质的功能。(3)干扰素刺激抑制丙型肝炎病毒复制的基因的筛选：I型干扰素是介导宿主病毒防御功能的关键分子。我们最近发现了三个IGS，GBP1，IFI27和IFI6-16，它们对丙型肝炎病毒的复制有抑制作用。通过免疫沉淀实验，我们发现GBP-1与丙型肝炎病毒NS5B RNA聚合酶特异性结合，据此，我们正在进一步筛选抗病毒化合物。这些结果可能有助于建立新的抗病毒治疗药物。

We have conducted studies of comprehensive screening of host proteins that suppress hepatitis C virus (HCV) replication using HCV subgenomic replication models and cell culture models.(1) High throughput screening of a library of 2,500 bioactive drugs, peptides, and compounds : we found 52 compounds that suppress or augment HCV replication (Gastroenterology 2006).(2) Establishment of antiviral therapies that target molecular chaperone and cyclophillin : we have reported that cyclosporine A suppress HCV replication through blockade of action of cyclophiline A, B and C. In this study, we next screened host proteins that interact with cyclophillins by bacterial two-hybrid system assay, and identified several proteins including G-protein coupled protein. We are now conducting studies to investigate functions of the proteins.(3) Screening of interferon-stimulated genes that suppress HCV replication : type-I interferon is a key molecule to mediate host virus defense functions. We have newly identified that three IGSs, GBP1, IFI27 and IFI6-16, show suppressive effects on HCV replication. Through immune precipitation assay, we have found that GBP-1 specifically binds HCV-NS5B RNA polymerase.With the above result we are now further conduct screening of antiviral compounds. These results may contribute to establish novel antiviral therapeutics.