丙型肝炎病毒RNA特异性核酶的切割活性研究

针对丙型肝炎病毒RNA(HCV-RNA)的5′非编码区和部分C区的二级结构,设计并合成了四个不同的锤头型核酶(ribozyme A, ribozyme B, ribozyme C₁, ribozyme C₂).首先应用体外切割实验筛选出作用于HCV-RNA起始密码子上游GTA↓位点的核酶RzA有较好的活性.为初步验证核酶RzA在细胞内的切割活性,经脂质体介导,将RzA-RNA与另一携带该核酶靶基因的质粒表达载体pCl-neo-luciferase(载体中荧光素酶基因受核酶靶基因的调控)共转染HepG₂细胞.通过测定荧光素酶基因的表达证实了核酶在细胞内有较好的切割活性.在此实验基础上,把RzA基因克隆至pCl-neo质粒表达载体中,再次经脂质体介导,将重组的表达载体pCl-neo-RzA与携带该核酶靶基因的质粒表达载体pCl-neo-luciferase共转染HepG₂细胞,获得了更好的切割效果.     

In vitro models for analysis of the hepatitis C virus life cycle

Chronic hepatitis C virus (HCV) infection affects approximately 170 million people worldwide. HCV infection is a major global health problem as it can be complicated with liver cirrhosis and hepatocellular carcinoma. So far, there is no vaccine available and the non-specific, interferon (IFN)-based treatments now in use have significant side-effects and are frequently ineffective, as only approximately 50% of treated patients with genotypes 1 and 4 demonstrate HCV clearance. The lack of suitable in vitro and in vivo models for the analysis of HCV infection has hampered elucidation of the HCV life cycle and the development of both protective and therapeutic strategies against HCV infection. The present review focuses on the progress made towards the establishment of such models.     

丙型肝炎病毒抗体化学发光免疫检测方法的建立及其临床应用简

目的：建立丙型肝炎病毒（rmv）抗体化学发光免疫检测方法,并分析其临床应用价值。方法：应用基因工程重组的HCV抗原包被微孔板,以辣根过氧化物酶标记的羊抗人IgG为二抗,并结合鲁米诺化学发光底物系统,建立HCV抗体化学发光免疫检测方法;应用HCV抗体诊断试剂国家参考品分析所建立方法的特异性、灵敏度、稳定性和精密性,并-9北京万泰公司的ELISA试剂盒同时检测临床血清样本350份,比较检测结果。结果：检测结果符合国家参考品质量标准。批内变异系数5．1％。6．6％,批间变异系数9-5％;试剂盒置37℃考核3d,其稳定性良好;与万泰公司的ELISA检测结果对照,阳性符合率分别为99．0％,阴性符合率分别为100％,总符合率为99．4％;Kappa值为0．986,一致性强度最强。结论：建立了特异、敏感和稳定的HCV抗体化学发光免疫检测方法,适用于HCV感染的批量筛查,具有较大的临床应用价值。     

Decreased interferon-alpha production and impaired regulatory function of plasmacytoid dendritic cells induced by the hepatitis C virus NS 5 protein

pDC are known to produce large amount of IFN-alpha/beta in response to viruses, and act as a major link between the innate and adaptive immune response. This study concentrated on the interaction of human peripheral blood derived pDC with HCV NS3, NS4, and NS5 proteins, and their maturation, cytokine secretion and functional properties. It was shown that HCV NS5 interferes with CD40L induced maturation of pDC as indicated by decreased expression of CD83 and CD86 markers. CpG ODN stimulated HCV NS3 and NS5 treated pDC showed decreased production of IFN-alpha. In the case of NS3, IFN-alpha production was reduced to 126 pg/ml as compared to 245 pg/ml in controls (P < 0.01), and with NS5, IFN-alpha production was reduced to 92 pg/ml as compared to 238 pg/ml in controls (P < 0.05). In the presence of HCV NS5, the T cell stimulatory capacity of pDC was impaired, as indicated by decreased proliferation of T cells, and decreased production by the T cells of IFN-gamma, which were down to 86 pg/ml as compared to 260 pg/ml in controls (P < 0.05). These results suggest that HCV NS5 impairs pDC function and is in agreement with several other in vivo studies indicating decreased numbers of, and dysfunctional pDC, in chronic HCV infected patients.     

Interferon antibodies in patients with infectious diseases

Interferons (IFNs) are generally recognized as the most important therapeutic agent in some infectious diseases such as chronic hepatitis B and C. Since the early clinical trials it was documented that the therapeutic use of IFNs could be complicated by the development of antibodies able to neutralize or to bind to the IFN molecule. After several years of research it is now widely accepted that the presence of circulating anti-IFN antibodies may affect the response to IFN. Here we summarize what is currently know on the clinical significance of antibodies to IFN in IFN-treated viral diseases patients.     

Human oncogenic viruses: Hepatitis B and hepatitis C viruses and their role in hepatocarcinogenesis

Chronic infections caused by hepatitis B virus (HBV) and/or hepatitis C virus (HCV) are the main risk factors for the development of hepatocellular carcinoma (HCC) in humans. Both viruses cause a wide spectrum of clinical manifestations ranging from healthy carrier state to acute and chronic hepatitis, liver cirrhosis, and HCC. HBV and HCV belong to different viral families (Hepadnoviridae and Flaviviridae, respectively); they are characterized by different genetic structures. Clinical manifestations of these viral infections result from the interaction between these viruses and host hepatocytes (i.e. between viral and cell genomes). Proteins encoded by both viruses play an important role in processes responsible for immortalization and transformation of these cells. Chronic inflammation determined by host immune response to the viral infection, hepatocyte death and their compensatory proliferation, as well as modulation of expression of some regulatory proteins of the cell (growth factors, cytokines, etc.) are the processes that play the major role in liver cancer induced by HBV and HCV.     

γ/δ T细胞与丙型肝炎病毒、乙型肝炎病毒感染

病毒性肝炎的发病机制迄今尚未完全明确,诸多证据表明,乙型肝炎病毒(HBV)及丙型肝炎病毒(HCV)所致肝炎可能是肝脏细胞免疫防御反应病毒入侵的结果。γ/δT细胞是新近认识的一个T细胞亚群,是机体抵抗外来病原微生物入侵的重要天然免疫细胞之一。近年研究发现,肝内富含γ/δT细胞,而病毒性肝炎肝内γ/δT细胞数量显著增高。目前有关γ/δT细胞与肝炎病毒感染的研究主要集中在HCV感染领域,即γ/δT细胞通过分泌多种细胞因子抑制体内HCV的复制。目前,有关γ/δT细胞与HBV感染的报道甚为少见。慢性HBV感染体内可能导致γ/δT细胞免疫学功能异常,这可能是导致体内病毒性乙型肝炎慢性化的主要原因之一。     

嵌合中国分离株基因的丙型肝炎病毒（1b／2a）细胞培养模型的建立

目的：建立嵌合中国分离株基因的丙型肝炎病毒（HCV）细胞培养模型。方法：利用3片段融合PCR的方法将中国HCV河北分离株（1b）的全长包膜蛋白基因引入JFH1（2a）株基因骨架,构建包膜蛋白基因区相互置换的嵌合HCV（1b／2a）全长基因组,经线性化后体外转录获得全长RNA,转染Huh7．5．1细胞系,用免疫荧光及蛋白印迹实验检测。结果：该RNA可以产生具有体外感染活性的嵌合HCV,且感染性可在共同培养的细胞间传播。结论：首次在国内建立了嵌合中国HCV分离株基因的HCV细胞培养体系。     

The decline in antibodies to hepatitis C virus during antiviral therapy

The goal of the study was to analyze B-cell response to hepatitis C virus during antiviral therapy among responders and non-responders. The content of antibodies to individual structural and non-structural HCV proteins was investigated during two years in three groups of patients: initial responders, non-responders and a reference group (without therapy). Treated patients in all groups exhibited the decrease in antibodies to analyzed HCV proteins, but with different patterns. The first statistically significant differences in the decline of the virus-specific antibodies between initial responders and non-responders were observed within the first three months after the beginning of therapy. Some treated patients demonstrated the decrease in antibody levels to HCV proteins after the end of therapy.     

Induction of Selenoprotein P mRNA during Hepatitis C Virus Infection Inhibits RIG-I-Mediated Antiviral Immunity

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丙型肝炎病毒受体研究进展

丙型肝炎病毒(HCV)入侵宿主细胞是在多种受体联合介导下才能完成的复杂过程.我们针对已报道的HCV 可能的细胞受体 CD81、低密度脂蛋白受体、B 族Ⅰ型清道夫受体、紧密连接蛋白家族、表皮生长子受体、酪氨酸激酶 EphA2受体、NPC1L1受体展开介绍,为今后研究和探索新型 HCV 疫苗和药物奠定基础.     

慢性丙型肝炎患者中丙型肝炎病毒准种变异研究进展

丙型肝炎病毒（HCV）具有较高的变异性,通常以准种的形式分布在感染者的体内,病毒容易逃离机体的免疫监控,因而无法被有效地清除,导致机体很难控制其感染的发展,故易转变成慢性肝炎。HCV准种变异在宿主体内的持续存在对病毒感染的控制、抗病毒药物和疫苗的发展都是一个巨大的挑战。,我们重点阐述近年来关于HCV准种变异及其与慢性丙型肝炎患者的机体免疫、疾病进展、治疗效果之间关系的研究进展。     

Hepatitis C virus (HCV) genotyping by annealing reverse transcription-PCR products with genotype-specific capture probes

The genotype of the hepatitis C virus (HCV) strain infecting a given patient is an important predictive factor for the clinical outcome of chronic liver disease and its response to anti-viral therapeutic agents. We herein sought to develop a new easy, sensitive and accurate HCV genotyping method using annealing genotype-specific capture probes (AGSCP) in an automation-friendly 96-well plate format. The validation of our new AGSCP was performed using the Standard HCV Genotype Panel. We then used both our AGSCP and the commercially available INNO-LiPA assay to analyze the HCV genotypes from 111 Korean patients. Discordant results were analyzed by direct sequencing. AGSCP successfully genotyped the standard panel. The genotypes of 111 patient samples were also obtained successfully by AGSCP and INNO-LiPA. We observed a high concordance rate (93 matched samples, 83.8%) between the two assays. Sequencing analysis of the 18 discordant results revealed that the AGSCP had correctly identified 12 samples, whereas the INNO-LiPA had correctly identified only 6. These results collectively indicate that AGSCP assay is a convenient and sensitive method for large-scale genotyping, and it may be a promising tool for the determination of HCV and other genotypes in clinical settings.     

用国产重组抗原研制丙肝病毒抗体检测试剂

用克隆表达的丙型肝炎病毒核心蛋白及非结构 3区蛋白、非结构 4区蛋白和非结构 5区蛋白作为抗原 ,研制装配了第三代丙肝病毒抗体检测试剂。用该试剂检测国家第三代丙肝病毒抗体检测试剂标准血清 ,40份阴性血清全部符合 ,40份阳性血清出现 1份假阴性。分析探讨了各种影响试剂质量的因素     

Serum zinc as a factor predicting response to interferon-alpha2b therapy in children with chronic hepatitis B

Although it has been unclear why more than 50% of children with chronic hepatitis B virus infection do not respond to interferon therapy, in some instances resistance to interferon probably is caused by an inability to stimulate appropriately cellular immune responses to hepatitis B virus. It is known that immune integrity is tightly linked to zinc status. We examined the relationship between serum zinc levels and response to interferon (INF)-α therapy in children with chronic hepatitis B. Twenty-five children with chronic hepatitis B infection were injected with 5 × 10⁶ units/m² recombinant IFN-α 2b subcutaneously three times weekly for 9 mo. Children were followed for at least 9 mo after the end of therapy. Sustained response was obtained in eight (32%) patients. Although initial serum zinc and alanine aminotransferase levels were significantly higher; initial hepatitis B Virus (HBV)-DNA values, hepatic activity index, periportal necrosis, and fibrosis scores were significantly lower in sustained responders than in nonresponders. Mean baseline serum zinc, alanine aminotransferase and HBV-DNA values, histologic activity index, periportal necrosis, and fibrosis scores were predictive of response to IFN-α 2b therapy. These findings suggest that serum zinc levels might be used as a factor predicting response to interferon-α 2b therapy, and so may help in identifying those children with a better chance of response.