MiR-122 in hepatitis B virus and hepatitis C virus dual infection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the most common causes of chronic liver diseases and hepatocelluar carcinomas. Over the past few years, the liver-enriched microRNA-122 (miR-122) has been shown to differentially regulate viral replication of HBV and HCV. It is notable that the level of miR-122 is positively and negatively regulated by HCV and HBV, respectively. Consistent with the well-documented phenomenon that miR-122 promotes HCV accumulation, inhibition of miR-122 has been shown as an effective therapy for the treatment of HCV infection in both chimpanzees and humans. On the other hand, miR-122 is also known to block HBV replication, and HBV has recently been shown to inhibit miR-122 expression; such a reciprocal inhibition between miR-122 and HBV suggests an intriguing possibility that miR-122 replacement may represent a potential therapy for treatment of HBV infection. As HBV and HCV have shared transmission routes, dual infection is not an uncommon scenario, which is associated with more advanced liver disease than either HBV or HCV mono-infection. Thus, there is a clear need to further understand the interaction between HBV and HCV and to delineate the role of miR-122 in HBV/HCV dual infection in order to devise effective therapy. This review summarizes the current understanding of HBV/HCV dual infection, focusing on the pathobiological role and therapeutic potential of miR-122.     

New animal models for hepatitis C viral infection and pathogenesis studies

Hepatitis C virus (HCV) is a major cause of chronic live disease, cirrhosis and hepatocellular carcinoma (HCC) In man, the pathobiological changes associated wit HCV infection have been attributed to both the immun system and direct viral cytopathic effects. Until now, th lack of simple culture systems to infect and propagat the virus has hampered progress in understandin the viral life cycle and pathogenesis of HCV infection including the molecular mechanisms implicated in HCV induced HCC. This clearly demonstrates the need t develop small animal models for the study of HCV associated pathogenesis. This review describes an discusses the development of new HCV animal models t study viral infection and investigate the direct effects o viral protein expression on liver disease.     

丁型肝炎病毒核酶结构改建及其对丙型肝炎病毒RNA的剪切活性

目的 观察经过结构改建的丁型肝炎病毒核酶（HDV核酶）对丙型肝炎病毒（HCV）基因组RNA是否存在剪切作用。方法 对HDV基因组核酶的茎IV区和底物结合区进行改建,获得3种针对HCV RNA的HDV核梅RzCI、RzC2和RzC3。体外转录制备含HCV RNA 5′－非编码区（5′-noncoding region,5′-NCR)及部分C区的底物RNA（HCV RNA5′-NCR-C）,进行5′端放射性标记。在一定的pH、温度、Mg^2 浓度和有或无去离子甲酰胺存在等条件下,将核酶和底物按摩尔比100：1混合,反应2h后聚丙烯酰胺凝电泳,放射自显影,推算剪切百分率。结果 RzCI和RzCI2可剪切HCV RNA5′-NCR-C,在适宜浓度的去离子甲酰胺存在时剪切效率较高,RzC3对底物几乎无剪切活性。结果 设计得当的HDV基因组核酶可以剪切异源性RNA分子HCV RNA。     

Understanding the interaction of hepatitis C virus with host DEAD-box RNA helicases

The current therapeutic regimen to combat chronic hepatitis C is not optimal due to substantial side effects and the failure of a significant proportion of patients to achieve a sustained virological response.Recently developed direct-acting antivirals targeting hepatitis C virus(HCV)enzymes reportedly increase the virologic response to therapy but may lead to a selection of drug-resistant variants.Besides directacting antivirals,another promising class of HCV drugs in development include host targeting agents that are responsible for interfering with the host factors crucia for the viral life cycle.A family of host proteins known as DEAD-box RNA helicases,characterized by nine conserved motifs,is known to play an important role in RNA metabolism.Several members of this family such as DDX3,DDX5 and DDX6 have been shown to play a role in HCV replication and this review will summarize our current knowledge on their interaction with HCV.As chronic hepatitis C is one of the leading causes of hepatocellular carcinoma,the involvement of DEADbox RNA helicases in the development of HCC will also be highlighted.Continuing research on the interaction of host DEAD-box proteins with HCV and the contribution to viral replication and pathogenesis could be the panacea for the development of novel therapeutics against HCV.     

Evidence for a relation between the viral load and genotype and hepatitis C virus-specific T cell responses

BACKGROUND/AIMS: The reason why patients with hepatitis C virus (HCV) genotype non-1 infection respond better to antiviral therapy than patients with genotype 1 infection is not known. The aim of this study is to explore the relation between the viral genotype, viral load, and the endogenous T cell response. METHODS: The viral genotype, the viral load, and the endogenous proliferative T cell response to the non-structural 3 protein (NS3) was analysed using serum and peripheral blood mononuclear cells from 103 patients with chronic HCV infection. RESULTS: Among 71 nontreated patients a T cell response was more common among those infected by genotype 3, as compared to those infected with genotype 1 (P<0.05). Among 32 patients undergoing antiviral therapy, presence of a T cell response was more common in genotype non-1 infected patients than in those infected by genotype 1 (P<0.01). Presence of a T cell response was related to a more rapid viral clearance (P<0,05), a negative HCV RNA test at week 12 (P<0.05), and a shorter viral half-life (P<0.05). CONCLUSIONS: The presence of an NS3-specific T cell response is related to the viral genotype and to a more rapid clearance of HCV RNA during antiviral therapy.     

Chaperones in hepatitis C virus infection

The hepatitis C virus(HCV) infects approximately 3% of the world population or more than 185 million people worldwide. Each year, an estimated 350000-500000 deaths occur worldwide due to HCV-associated diseases including cirrhosis and hepatocellular carcinoma. HCV is the most common indication for liver transplantation in patients with cirrhosis worldwide. HCV is an enveloped RNA virus classified in the genus Hepacivirus in the Flaviviridae family. The HCV viral life cycle in a cell can be divided into six phases:(1) binding and internalization;(2) cytoplasmic release and uncoating;(3) viral polyprotein translation and processing;(4) RNA genome replication;(5) encapsidation(packaging) and assembly; and(6) virus morphogenesis(maturation) and secretion. Many host factors are involved in the HCV life cycle. Chaperones are an important group of host cytoprotective molecules that coordinate numerous cellular processes including protein folding, multimeric protein assembly, protein trafficking, and protein degradation. All phases of the viral life cycle require chaperone activity and the interaction of viral proteins with chaperones. This review will present our current knowledge and understanding of the role of chaperones in the HCV life cycle. Analysis of chaperones in HCV infection will provide further insights into viral/host interactions and potential therapeutic targets for both HCV and other viruses.     

Permanent response to alpha-interferon therapy in chronic hepatitis C is preceded by rapid clearance of HCV-RNA from serum

Background/Aims: Prediction of response to interferon therapy is important in the management of chronic hepatitis C. Pre-therapy data are valuable but they may be inaccurate in some cases. Our aim was to investigate whether the biochemical and virological events that occur early during interferon therapy in chronic hepatitis C may predict the final result of the treatment.Methods: ALT and serum HCV-RNA were serially measured in 53 HCV-RNA-positive patients who received a standard 6-month course of interferon therapy. Eleven patients with a sustained response, 23 who responded but subsequently relapsed and 19 who did not respond were studied. HCV-RNA was measured with a commercial kit (Amplicor HCV).Results: After 4 weeks of treatment, HCV-RNA became negative in 73% of sustained responders, in 26% of transient responders (p=0.02) and in none of the non-responders. Corresponding figures after 8 weeks of therapy were 82% in sustained responders, 61% in transient responders and 9% in non-responders. The difference between sustained and transient responders at this times was not significant. After 4 weeks of therapy, 82% of sustained responders, 52% of transient responders and none of the non-responders presented normalization of alanine transferase. The difference between sustained and transient responders was not significant. Corresponding figures for normalization of alanine transferase at 8 weeks were 82%, 96% and 0% respectively. At the end of treatment, all sustained responders, 70% of transient responders and none of the non-responders had cleared HCV-RNA from serum.Conclusions: A rapid normalization of alanine transferase induced by interferon therapy is associated with response, but does not differentiate between transient and permanent response. In contrast, clearance of HCV-RNA after 4 weeks of treatment, but not after 8 weeks, is significatively associated with sustained response. Testing for HCV-RNA early during interferon administration may be valuable for further decisions concerning therapy in patients with chronic hepatitis C.     

Adiponectin serum level in chronic hepatitis C infection and therapeutic profile

Hepatic steatosis is commonly seen in the patients with chronic hepatitis C virus(HCV) infection. HCV is closely associated with lipid metabolism,and viral steatosis is more common in genotype 3 infection owing to a direct cytopathic effect of HCV core protein. In non-genotype3 infection,hepatic steatosis is considered largely to be the result of the alterations in host metabolism; metabolic steatosis is primarily linked with HCV genotype 1. A d i p o s e t i s s u e s e c r e t e s d i f f e r e n t h o r m o n e s involved in glucose and lipid metabolisms. It has been demonstrated that adipocytokines are involved in the pathogenesis of non-alcoholic fatty liver disease,as the decreased plasma adiponectin levels,a soluble matrix protein expressed by adipoctyes and hepatocyte,are associated with liver steatosis. Various studies have shown that steatosis is strongly correlated negatively with adiponectin in the patients with HCV infection. The role of adiponectin in hepatitis C virus induced steatosis is still not completely understood,but the relationship between adiponectin low levels and liver steatosis is probably due to the ability of adiponectin to protect hepatocytes from triglyceride accumulation by increasing β-oxidation of free fatty acid and thus decreasing de novo free fatty acid production.     

小发夹RNA体外抑制乙型肝炎病毒X蛋白表达的实验研究

目的构建靶向乙型肝炎病毒X基因（HBX）的shRNA表达载体pSilencer3．1-shHBX,观察其体外抑制HBX在HepG2细胞中表达的作用,为应用RNA干扰技术进一步研究HBX基因的功能奠定基础。方法设计并构建靶向HBx的shRNA表达载体pSilencer3．1-shHBX,脂质体转染法将HBX表达载体pcDNA3．1-HBx与pSilencer3．1-shHBX共转染人肝癌HepG2细胞,培养72h后以RT-PCR检测HBX基因表达情况,以Western blot检测HBX蛋白的表达量。结果经酶切和测序鉴定,构建的重组质粒pSilencer3．1-shHBX与设计一致。该质粒使HBX基因mRNA表达量降低47．1％,使HBx蛋白表达量降低58．9％,而阴性对照质粒无此作用。结论成功构建靶向HBXshRNA表达载体pSilencer3．1-shHBX,该质粒可体外抑制HBX在HepG2细胞中的表达。     

HBV X基因-HCV C基因cDNA融合基因真核表达载体的构建及其表达

目的：构建HBV X-HCV C融合基因真核表达载体，并获得稳定表达该基因的HepG2细胞株。方法：双酶切质粒pXT1-X，得到完整的HBV X基因片段后，将其插入到质粒PBK-CMV和PBK-HCVC的相应酶切位点，得到重组质粒PBK-X和PBK-X-C；再将质粒RBK-CMV、PBK-X、PBK-HCV C和PBK-X-C分别导入肝癌细胞株HepG2中，G418筛选，RT-PCR、蛋白印迹鉴定HBV X和HCV C蛋白表达。结果：质粒PBK-CMV、PBK-X、PBK-HCV C和PBK-X-C在HepG2细胞中有稳定表达。结论：成功构建HBV X-HCVC融合基因真核表达载体，并获得稳定表达该基因的HepG2细胞株。     

Effects of Nigella sativa on outcome of hepatitis C in Egypt

AIM: To evaluate the safety, efficacy and tolerability of Nigella sativa (N. sativa ) in patients with hepatitis C not eligible for interferon (IFN)-α. METHODS: Thirty patients with hepatitis C virus (HCV) infection, who were not eligible for IFN/ribavirin therapy, were included in the present study. Inclusion criteria included: patients with HCV with or without cirrhosis, who had a contraindication to IFN-α therapy, or had refused or had a financial constraint to IFN-α therapy. Exclusion criteria included: patients on IFN-α therapy, infection with hepatitis B or hepatitis Ⅰ virus, hepatocellular carcinoma, other malignancies, major severe illness, or treatment non-compliance. Various parameters, including clinical parameters, complete blood count, liver function, renal function, plasma glucose, total antioxidant capacity (TAC), and polymerase chain reaction, were all assessed at baseline and at the end of the study. Clinical assessment included: hepato and/ or splenomegaly, jaundice, palmar erythema, flapping tremors, spider naevi, lower-limb edema, and ascites. N. sativa was administered for three successive months at a dose of (450 mg three times daily). Clinical response and incidence of adverse drug reactions were assessed initially, periodically, and at the end of the study. RESULTS: N. sativa administration significantly improved HCV viral load (380808.7 ± 610937 vs 147028.2 ± 475225.6, P = 0.001) and TAC (1.35 ± 0.5 vs 1.612 ± 0.56, P = 0.001). After N. sativa administration, the following laboratory parameters improved: total protein (7.1 ± 0.7 vs 7.5 ± 0.8, P = 0.001), albumin (3.5 ± 0.87 vs 3.69 ± 0.91, P = 0.008), red blood cell count (4.13 ± 0.9 vs 4.3 ± 0.9, P = 0.001), and platelet count (167.7 ± 91.2 vs 198.5 ± 103, P = 0.004). Fasting blood glucose (104.03 ± 43.42 vs 92.1 ± 31.34, P = 0.001) and postprandial blood glucose (143.67 ± 72.56 vs 112.1 ± 42.9, P = 0.001) were significantly decreased in both diabetic and non-diabetic HCV patients. Patients with lower-limb edema de     

Emerging drugs for chronic hepatitis C.

Hepatitis C virus (HCV) is a major cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma worldwide. A combination therapy comprising pegylated interferon and ribavirin currently represents the most effective therapy for chronic HCV infection. The limitations of this current therapy mainly its efficacy and significant side effects have prompted the development of new drugs. Few categories of therapeutic agents appear promising for future therapy, e.g. novel interferons, ribavirin analogs, antisense oligonucleotides, short interfering RNAs, ribozymes, enzyme inhibitors, immunomodulatory agents, antifibrotic agents, therapeutic vaccines and antibodies. Few drugs belong to afore-mentioned categories have already reached the different clinical phases of development. The present article highlights the status of current available therapies and emerging drugs for the treatment of hepatitis C.     

乙型肝炎病毒X基因-丙型肝炎病毒C基因共表达对血管内皮细胞生长因子的影响

目的建立乙型肝炎病毒X基因-丙型肝炎病毒C基因（HBV X—HCV C）共表达HepG2细胞模型，并探讨其对血管内皮细胞生长因子表达的影响。方法双酶切质粒pXT1—X，得到完整的HBV X基因片段后，将其插入到质粒PBK—CMV和PBK—HCV C的相应酶切位点，得到重组质粒PBK—X和PBK—X—C；再将质粒PBK—CMV、PBK—X、PBK—HCV C和PBK—X—C分别导入肝癌细胞株HepG2中，G418筛选，逆转录聚合酶链反应、Western blot鉴定HBV X和HCV C蛋白表达，免疫组织化学、Western blot检测血管内皮细胞生长因子蛋白质表达。结果质粒PBK—CMV、PBK—X、PBK—HCV C和PBK—X—C在HepG2细胞中有稳定表达。共表达HBV X—HCV C蛋白的细胞血管内皮细胞生长因子蛋白质表达较转染空载体的细胞及单独表达HBV X、HCV C蛋白的细胞明显升高。结论HBV X—HCV C共表达能显著上调血管内皮细胞生长因子蛋白质表达，提示HBV、HCV可能具有协同致癌作用。     

Management of telaprevir-based triple therapy for hepatitis C virus recurrence post liver transplant

AIM: To characterize management of telaprevir (TVR)-based triple therapy of hepatitis C virus (HCV) reinfection after liver transplantation (LT).METHODS: We retrospectively analyzed safety and efficacy of telaprevir - based triple therapy in a single center cohort of 19 patients with HCV genotype (GT) 1 recurrence after LT, with respect to factors possibly predicting sustained viral response (SVR) or non-SVR. All patients were treated with TVR, pegylated (PEG) and ribavirine (RBV) for 12 wk followed by a dual phase with PEG/RBV for 12 wk in 7 patients and for 36 wk in 5 patients.RESULTS: In total 11/19 (58%) of patients achieved a sustained response. All (11/11) SVR patients showed a rapid viral response at treatment weeks 4 and 11/14 rapid virological response (RVR) patients achieved SVR. Notably, all (7/7) patients who completed 48 wk of therapy and 80% (4/5) patients who completed 24 wk of therapy achieved SVR24. Treatment failure was significantly (P > 0.049) more frequent in GT1a infection (5/7) compared to GT1b (3/12) infection and was associated with emergence of resistance-associated mutations in the NS3 protease domain. Bilirubin level at baseline is also related to SVR (P > 0.030). None of the patients had to discontinue treatment due to side effects.CONCLUSION: RVR, GT and bilirubin are clearly related to achievement of SVR. Providing a thorough patient selection and monitoring, a full course of TVR-based triple therapy in LT patients is feasible and achieves high SVR rates.     

Status of hepatitis C virus vaccination:Recent update

Hepatitis C virus(HCV) infection is still a major public health problem worldwide since its first identification in 1989. At the start, HCV infection was post-transfusion viral infection, particularly in developing countries. Recently, due to iv drug abuse, HCV infection became number one health problem in well-developed countries as well. Following acute HCV infection, the innateimmune response is triggered in the form of activated coordinated interaction of NK cells, dendritic cells and interferon α. The acquired immune response is then developed in the form of the antibody-mediated immune response(ABIR) and the cell-mediated immune response(CMIR). Both are responsible for clearance of HCV infection in about 15% of infected patients. However, HCV has several mechanisms to evade these antivirus immune reactions. The current review gives an overview of HCV structure, immune response and viral evasion mechanisms. It also evaluates the available preventive and therapeutic vaccines that induce innate, ABIR, CMIR. Moreover, this review highlights the progress in recent HCV vaccination studies either in preclinical or clinical phases. The unsatisfactory identification of HCV infection by the current screening system and the limitations of currently available treatments, including the ineligibility of some chronic HCV patients to such antiviral agents, mandate the development of an effective HCV vaccine.     

miR-122–based therapies select for three distinct resistance mechanisms based on alterations in RNA structure

Hepatitis C virus (HCV) is a positive-sense RNA virus that interacts with a liver-specific microRNA called miR-122. miR-122 binds to two sites in the 5′ untranslated region of the viral genome and promotes HCV RNA accumulation. This interaction is important for viral RNA accumulation in cell culture, and miR-122 inhibitors have been shown to be effective at reducing viral titers in chronic HCV-infected patients. Herein, we analyzed resistance-associated variants that were isolated in cell culture or from patients who underwent miR-122 inhibitor–based therapy and discovered three distinct resistance mechanisms all based on changes to the structure of the viral RNA. Specifically, resistance-associated variants promoted riboswitch activity, genome stability, or positive-strand viral RNA synthesis, all in the absence of miR-122. Taken together, these findings provide insight into the mechanism(s) of miR-122–mediated viral RNA accumulation and provide mechanisms of antiviral resistance mediated by changes in RNA structure.

Hepatitis C virus (HCV) is a positive-sense RNA virus of the Flaviviridae family. The ∼9.6 kb HCV genomic RNA consists of a single open reading frame, which gives rise to the viral polyprotein that is processed into the 10 mature viral proteins flanked by highly structured 5′ and 3′ untranslated regions (UTRs) (1, 2). As a positive-sense RNA virus, the viral genome itself must serve as a template for the different stages of the viral life cycle, including viral translation, replication, and packaging (2). To this end, the viral 5′ and 3′ UTRs contain several cis-acting RNA elements that play important roles in directing the various stages of the viral life cycle (2–4). Specifically, the 5′ UTR contains the viral internal ribosomal entry site (IRES) made up of stem–loops (SL) II-IV, which is required for viral translation, while sequences and SL structures in both the 5′ (SLI-II) and 3′ UTRs (variable region, polyU/UC-tract, and 96-nt X-tail) are required for viral RNA replication (2, 5–8). Additionally, the 5′ terminus of the HCV genome interacts with the highly abundant, liver-specific human microRNA (miRNA), miR-122 (9–12).miR-122 is a highly expressed miRNA in the liver with ∼135,000 copies per hepatocyte (9, 13). While miRNAs typically interact with the 3′ UTRs of their target messenger RNAs (mRNAs) to dampen gene expression, miR-122 interacts to two sites in the 5′ UTR (site 1 and site 2) of the viral genome, and these interactions promote viral RNA accumulation (9, 10, 12). Several recent studies have led to a new model for miR-122:HCV RNA interactions that suggest that miR-122 plays at least three roles in the HCV life cycle (Fig. 1) (14–17). Firstly, the HCV 5′ UTR is thought to initially adopt an energetically favorable conformation (termed SLII^alt), which results in the recruitment of an Ago:miR-122 complex to site 2 of the HCV genome. This results in an RNA chaperone-like switch in conformation, akin to a bacterial riboswitch (18), resulting in the formation of SLII and allowing the viral IRES (SLII-IV) to form (15–17). Secondly, this change in conformation allows the recruitment of Ago:miR-122 to site 1, which protects the 5′ terminus from pyrophosphatase activity and subsequent exoribonuclease-mediated decay (12, 14, 19–21). Finally, the Ago protein bound to site 2 makes direct contact with the viral IRES, promoting HCV IRES-mediated translation (16).Open in a separate windowFig. 1.Model of miR-122 interactions with the HCV genome. The HCV genomic RNA is thought to enter the cell in an energetically stable conformation termed SLII^alt. The recruitment of the first Ago:miR-122 molecule to the accessible (unpaired) site 2 serves as an RNA chaperone, akin to a bacterial riboswitch, which refolds the RNA into the functional SLII conformation and allows the viral IRES (SLII-IV) to form (1). Subsequent recruitment of a second Ago:miR-122 molecule to site 1 promotes genome stability by protecting the 5′ terminus from cellular pyrophosphatases and exoribonuclease-mediated decay (2). In order to accommodate the Ago:miR-122 complex at site 1, the Ago:miR-122 complex at site 2 releases its auxiliary interactions but is likely stabilized by interactions between the Ago protein and SLII of the HCV IRES (3). Collectively, these interactions promote HCV IRES-mediated translation. miR-122 seed and auxiliary binding sequences are indicated (red).Due to the importance of miR-122 in the HCV life cycle, two miR-122 inhibitors (antisense oligonucleotides), the first miRNA-based drugs to enter clinical trials, have been developed and used to treat chronic HCV infection in the clinic (22, 23). Both Miravirsen (Santaris Pharma, a/s) and RG-101 (Regulus Therapeutics) miR-122 inhibitors have completed Phase II or Ib clinical trials, respectively, to investigate their clinical efficacy in chronic HCV infection (22, 23). Excitingly, both treatments led to dose-dependent and sustained reductions in viral loads; and, in the latter study, two patients achieved a sustained virological response (at least up to 76 wk posttreatment) after receiving a single dose of RG-101 (23). Neither treatment was associated with significant adverse events or long-term safety issues, suggesting that antisense targeting of miR-122 may be an effective treatment that could be used in future combination therapies. Interestingly, while no resistance was apparent during treatment, when viral RNA rebounded after the cessation of the inhibitor, several resistance-associated variants (RAVs) were identified in the 5′ UTR of the HCV genome (23). Specifically, C3U (genotype 1) was identified as a RAV in both the Miravirsen and RG-101 trials, while the C2GC3U (genotype 3/4) RAV was identified in the RG-101 trial alone, with both RAVs identified in multiple patients (22, 23). Additional RAVs were identified in cell culture, including studies performed with genotype 1 (A4C) and genotype 2 (U4C, G28A, and C37U), which were identified alone (A4C and G28A) or in combination with other RAVs (i.e., G28A+C37U, U4C+G28A+C37U) (24–26). As the cell culture–based studies identifying RAVs were performed with genotype 2 and the majority of the RAV nucleotide identities are present in genotype 2 (save for A4C, although U4C was deemed an equivalent RAV observed in this genotype), herein, we explored the mechanism of action of these collective RAVs (C2GC3U, C3U, U4C, G28A, and C37U) using genotype 2a (J6/JFH-1) reporter RNAs (Fig. 2A) (22–26). Previous work suggests that the G28A mutation is “riboswitched” and promotes the formation of the functional SLII structure even in the absence of miR-122 (16, 17). Similar to G28A, we hypothesized that the other RAVs also alter the structure of the viral RNA in a manner that negates the requirement for one or more miR-122 activities. Thus, we sought to provide insight into the mechanism(s) of action of the RAVs using RNA structure analysis and assays for viral RNA accumulation and decay. Our analyses suggest that each of the RAVs alter the structure of the viral RNA, and we identify three distinct resistance mechanisms based on unique changes in viral RNA structure.Open in a separate windowFig. 2.RAV accumulation in cell culture. (A) The positions of the RAVs on the 5′ UTR of the HCV RNA. Nucleotides 1 to 45 of the HCV genome (black) and the binding topology of the two miR-122 molecules (teal) are shown. Full-length RLuc HCV genomic reporter RNAs (WT and RAVs) were coelectroporated with a capped Firefly fuciferase (FLuc) mRNA into (B) Huh-7.5 or (C) miR-122 KO cells. Full-length RLuc HCV genomic reporter RNAs containing mutations at (D) site 1 (S1:p3A) or (E) site 2 (S2:p3A) were coelectroporated with a capped FLuc mRNA and compensatory miR-122p3U molecules into miR-122 KO cells. Luciferase activity was measured at the indicated time points post-electroporation. The limit of detection is indicated, and all data are representative of at least three independent replicates. Error bars represent the SD of the mean.     

输血后丙型肝炎病毒感染的血清病毒定量研究

目的 研究血清丙型肝炎病毒（ＨＣＶ）含量与ＨＣＶ致病的关系及ＨＣＶ含量与抗－ＨＣＶ和丙氨酸转氨酶（ＡＬＴ）的相关性。方法 以逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）法对ＨＣＶ感染的受血及相关供血系列血清进行ＨＣＶ ＲＮＡ定量分析,同时检测ＡＬＴ与抗－ＨＣＶ。结果 致输血后ＨＣＶ感染的供血中,ＨＣＶ ＲＮＡ平均含量为１０＾８．６拷贝／Ｌ,抗－ＨＣＶ及ＡＬＴ的异常检出率随ＨＣＶ ＲＮＡ滴度升高而增加。结论     

合并乙型肝炎病毒感染对丙型肝炎病毒核心抗原检测的影响

目的 探讨合并HBV感染对慢性HCV感染者血清丙型肝炎病毒核心抗原(HCVcAg)检出情况的影响. 方法 收集2005年12月-2009年10月慢性丙型肝炎患者和HBV/HCV合并感染者资料,检测血清HCVcAg和HCV RNA,对后者血清进行HBV DNA、HBeAg检测,分析HCVcAg检出率与HBeAg、HBV DNA定量检测的关系.用独立两组多分类的X2检验方法进行统计学分析. 结果 共收集88例慢性丙型肝炎患者和62例HBV/HCV合并感染者资料,血清HCVcAg的检出率分别为72.7％(64/88)和38.7％ (24/62),两者比较,x2= 17.358,P＜0.01,差异有统计学意义.HCV RNA检出率分别为81.8％ (72/88)和53.2％ (33/62),两者比较,x2=20.110,P＜0.01,差异有统计学意义.62例HBV/HCV合并感染者血清中,HBeAg阳性和HBeAg阴性感染者HCVcAg检出率分别为28.6％ (12/42)和60.0％ (12/20),两者比较,x2=5.641,P=0.011,差异有统计学意义.HCV RNA阳性率分别为42.9％ (18/42)和80.0％ (16/20),两者比较,X2=7.547,P＜ 0.01,差异有统计学意义.HBV DNA阳性和阴性时HCVcAg检出率分别为39.1％ (18/46)和37.5％ (6/16),两者比较,P＞0.05,差异无统计学意义.与单纯HCV感染者血清HCVcAg检出率72.7％ (64/88)比较,HBeAg阴性合并感染者为60.0％ (12/20),x2=1.266,P=0.261,差异无统计学意义;HBV DNA阴性合并感染者为37.5％ (6/16),x2=7.635,P＜0.01,差异有统计学意义.结论 HBV/HCV合并感染时HCVcAg检出率较低,可能是由于HBeAg抑制HCV的复制,从而减少HCVcAg的表达所致.