Dual gRNAs guided CRISPR/Cas9 system inhibits hepatitis B virus replication

AIM: To screen and investigate the effective g RNAs against hepatitis B virus(HBV) of genotypes A-D.METHODS: A total of 15 g RNAs against HBV of genotypes A-D were designed. Eleven combinations of two above g RNAs(dual-g RNAs) covering the regulatory region of HBV were chosen. The efficiency of each g RNA and 11 dual-g RNAs on the suppression of HBV(genotypes A-D) replication was examined by the measurement of HBV surface antigen(HBs Ag) or e antigen(HBe Ag) in the culture supernatant. The destruction of HBV-expressing vector was examined in Hu H7 cells co-transfected with dual-g RNAs and HBVexpressing vector using polymerase chain reaction(PCR) and sequencing method, and the destruction of ccc DNAwas examined in Hep AD38 cells using KCl precipitation, plasmid-safe ATP-dependent DNase(PSAD) digestion, rolling circle amplification and quantitative PCR combined method. The cytotoxicity of these g RNAs was assessed by a mitochondrial tetrazolium assay.RESULTS: All of g RNAs could significantly reduce HBs Ag or HBe Ag production in the culture supernatant, which was dependent on the region in which g RNA against. All of dual g RNAs could efficiently suppress HBs Ag and/or HBe Ag production for HBV of genotypes A-D, and the efficacy of dual g RNAs in suppressing HBs Ag and/or HBe Ag production was significantly increased when compared to the single g RNA used alone. Furthermore, by PCR direct sequencing we confirmed that these dual g RNAs could specifically destroy HBV expressing template by removing the fragment between the cleavage sites of the two used g RNAs. Most importantly, g RNA-5 and g RNA-12 combination not only could efficiently suppressing HBs Ag and/or HBe Ag production, but also destroy the ccc DNA reservoirs in Hep AD38 cells.CONCLUSION: These results suggested that CRISPR/Cas9 system could efficiently destroy HBV expressing templates(genotypes A-D) without apparent cytotoxicity. It may be a potential approach for eradication of persistent HBV ccc DNA in chronic HBV infection patients.

天然小分子诱生机体抗病毒细胞因子研究

天然小分子是中药、药用植物和天然药物的重要活性成分,是重要的药物资源研究方向和内容。大多数抗病毒药用植物,如夏枯草、黄芪和黄芩等,其活性成分均为天然小分子。抗病毒细胞因子为一类生物体中具有联系机体固有免疫和特异性免疫应答,捕杀或抑制体内病毒的小分子功能蛋白。近年来研究表明,植物中的多酚类、苷类以及寡糖等小分子化合物可调控机体内源抗病毒细胞因子的表达水平,继而作用于各类DNA或RNA病毒:一方面刺激机体产生抗病毒蛋白,直接捕杀病毒;另一方面联动机体固有免疫和获得性免疫应答,抑制病毒复制,抗病毒感染,清除被病毒感染的细胞。本文综述了近几十年药用植物天然小分子诱生机体细胞因子抗病毒的作用及机制研究,并由此提出这类活性天然小分子将可能成为新一类的抗病毒药物。

基因工程干扰素(IFN—α2b)抗柯萨奇和单纯疱疹病毒效应

本文采用微量细胞病变抑制法在Ｗｉｓｈ 及Ｖｅｒｏ 细胞上研究了ＩＦＮ—α２ｂ 抗ＣｏｘＢ３ 型及ＨＳＶ—１ 型和ＨＳＶ—Ⅱ型病毒的作用。结果表明，安达芬和干扰能ＩＨＮα２ｂ 在Ｗｉｓｈ 或Ｖｅｒｏ 细胞上５００ＩＵ／ｍｌ 分别可以抗３ｌｏｇ４ 或１０００ＴＣＩＤ５０ ，５０ＩＵ／ｍｌ 可以抗２ｌｏｇ４ 或１００ ＴＣＩＤ５０ ，５ＩＵ／ｍｌ 可以抗１ｌｏｇ４ 或１０ ＴＣＩＤ５０ 的ＣｏｘＢ３ 型或ＨＳＶ—１ 型和ＨＳＶ—Ⅱ型病毒感染细胞。提示安达芬和干扰能均显示明显的抗病毒效应。

Use of entecavir in hepatitis B virus reactivation of a patient with non-Hodgkin's lymphoma

We read with interest the case report by Liu et al and the correspondence by Tuna et al regarding this case. Liu et al described hepatitis B virus(HBV) reactivation in a patient with non-Hodgkin's lymphomaafter withdrawal of lamivudine prophylaxis. When HBV reactivation was observed three months after lamivudine withdrawal, entecavir 0.5 mg daily was started. HBV DNA level was moderately elevated(104 copies/m L) at that time. So, we could not understand why a potent antiviral like entecavir was required for this case. In addition to this, entecavir must be used at a dose of 1 mg in patients with prior prophylactic treatment with lamivudine. As stated by Tuna et al duration of lamivudine prophylaxis in this case might be insufficient and HBV reactivation might have occured for this reason. So, we suppose that resolution of HBV reactivation might also be achieved with lamivudine instead of entecavir in this case.

EGCG-S Impacts Oxidative Stress and Infection of Enterovirus 69 in Lung Cells

Enteroviruses are responsible for emerging diseases which cause diverse symptoms and may result in neurological complications. An antiviral with multiple mechanisms of action can help prevent enterovirus mediated disease despite differences in the pathogenesis between enteroviruses, including the recently identified enterovirus 69 (EV-69) for which pathogenesis is not well understood. This study investigated the efficacy of epigallocatechin-3-gallate stearate (EGCG-S), a modified form of the antioxidant green tea catechin epigallocatechin-3-gallate (EGCG), in inhibiting EV-69 infection of lung fibroblast cells in vitro. Treatment with EGCG-S resulted in moderate protection from EV-69 mediated cytotoxicity as demonstrated by increased metabolic activity as well as maintenance of cell morphology and mitochondrial function. These effects were correlated with reduced hydrogen peroxide production in infected cells following EGCG-S treatment with concentrations less than 100 μM, suggesting a role for inhibition of EV-69 mediated oxidative stress. This study provides insight into characteristics of EV-69 infection as well as the efficacy of EGCG-S mediated inhibition of EV-69 infection.