干扰素诱导抗病毒蛋白的基因多态性与抗病毒疗效的关系

人们对干扰素的研究是从发现病毒间的干扰现象开始的。对干扰素分类、受体、信号转导及抗病毒活性表达作用机理的了解,为临床应用干扰素抗病毒治疗开辟了广阔的前景。近年国内外有关人体基因多态性与药物疗效关系的研究成果不断涌现,现将其中有关干扰素诱导抗病毒蛋白的基因多态性与抗病毒疗效的关系做一综述。     

干扰素诱导抗病毒蛋白的基因多态性与抗病毒疗效的关系

人们对干扰素的研究是从发现病毒间的干扰现象开始的。对干扰素分类、受体、信号转导及抗病毒活性表达作用机理的了解,为临床应用干扰素抗病毒治疗开辟了广阔的前景。近年国内外有关人体基因多态性与药物疗效关系的研究成果不断涌现,现将其中有关干扰素诱导抗病毒蛋白的基因多态性与抗病毒疗效的关系做一综述。     

广东地区慢性丙型肝炎患者IL28B基因多态性与抗病毒疗效的关系

目的 研究广东地区慢性丙型肝炎患者（CHC）白细胞介素28B（IL28B）基因单核苷酸多态性（single nucleotide polymorphism,SNP）的分布特点及其与抗病毒疗效之间的关系,为合理选择经济有效的个体化抗病毒治疗方案提供依据,提高CHC的治疗应答率.方法 对74例CHC患者给予聚乙二醇干扰素（PEG-IFN）联合利巴韦林（RBV）抗病毒治疗,疗程48周或72周,停药后随访24周.通过PCR测序,检测所有患者的IL28B（rs8099917、rs12979860、rs12980275）位点SNP,以快速病毒学应答率（RVR）及持续病毒学应答率（SVR）作为疗效的主要评价指标,比较IL28B不同基因型与抗病毒疗效的关系,评估IL28 BSNP在CHC患者治疗应答中的作用.结果 74例患者中,rs8099917位点基因型为TT、TG、GG各63（85.1％）、11（14.9％）、0（0％）例,rs12979860位点基因型为CC、CT、TT各60（81.1％）、14（18.9％）、0（0％）例,rs12980275位点基因型为AA、AG、GG各57 （77.0％）、17（23.0％）、0（0％）例.对HCV 1型患者,上述三个位点中仅rs12979860 CC型与SVR有关,结果有统计学差异（SVR组vs NonSVR组,88.4％ vs 58.3％,P＜0.05）;对非HCV1型患者,rs8099917、rs12979860、rs12980275三个位点与RVR和SVR无关,结果无统计学差异（P＞0.05）.结论 广东地区CHC患者IL28B基因rs8099917、rs12979860、rs12980275位点分别以TT、CC、AA为主;对于HCV 1型CHC患者,rs12979860位点的基因型可以作为治疗前SVR的一个重要预测因子.     

p53基因多态性与卵巢癌

在抑癌基因中，p53与肿瘤的关系较早受到人们的重视，而且是迄今研究的最为广泛、最为系统的抗癌基因之一。本文论述p53基因的结构与蛋白的功能，以及p53基因的几个多态性位点。就近年来p53基因的多态性与散发性和遗传性卵巢癌的相关研究做一简要综述，并对以后p53基因多态性的研究方向提出一些建议。     

载脂蛋白E基因多态性与血管性痴呆关系的研究

为探讨载脂蛋白Ｅ（ＡｐｏＥ）基因多态性与血管性痴呆（ｖａｓｃｕｌａｒｄｅｍｅｎｔｉａ，ＶＤ）的关系，采用单链构象多态性分析（ＰＣＲ－ＳＳＣＰ）检测了３７例ＶＤ患者的ＡｐｏＥ基因型，并与４０例同龄对照组及４０例非痴呆脑梗塞组比较，同时检测血脂、脂蛋白及部分载脂蛋白。结果表明，ＶＤ组ε４基因频率明显高于对照组（Ｐ＜０．０１）和非痴呆脑梗塞组（Ｐ＜０．０５），ＶＤ患者中携ε４等位基因者血ＴＣ及ＬＤＬ－Ｃ水平显著高于携ε２、ε３者。提示：ε４基因可能是ＶＤ的危险因子，其机理可能与大脑血管性和变性性损害有关。     

IL-28B基因多态性与丙型肝炎自然转归的相关性研究

目的:探讨IL-28B单核苷酸多态性与丙型肝炎病毒(HCV)感染自然转归的相关性。方法:采用Sanger基因测序法检测广州地区无偿献血人群中266名HCV感染者(107名自发清除者和159名慢性感染者)和97名健康献血者IL-28B rs12979860位点基因型和等位基因,并统计分析其在HCV感染者与健康献血者,HCV慢性感染者与健康献血者,HCV自发清除者与慢性感染者中的分布差异。结果:159名HCV慢性感染者,107名自发清除HCV者和97名健康献血者多表现为CC基因型,分别占83.6%、95.3%和86.6%,CT基因型分别占16.4%、4.7%和13.4%,未发现TT基因型。HCV感染者和健康献血者,HCV慢性感染者和健康献血者CC/CT基因型分布差异均无统计学意义(χ2=0.204,P=0.652;χ2=0.406,P=0.524),但在HCV慢性感染者和自发清除HCV者中CC/CT基因型分布差异有统计学意义(χ2=8.474,P=0.004),自发清除组中CC基因型比率高于慢性感染组,自发清除组C等位基因的频率高于慢性感染组(χ2=7.949,P=0.005)。结论:在广州献血人群中,IL-28B rs12979860基因多态性与HCV的易感性不相关,但与HCV感染的自发清除相关,表现为C等位基因有利于丙型肝炎病毒(HCV)的自发清除。     

海南汉族人群九个纤维蛋白原基因多态性及其与血浆纤维蛋白原水平的关系

目的 调查海南汉族健康人群αTaqⅠ和βBclⅠ、HinfⅠA／C、448G／A、βBsmA ⅠG／C、＋1689T／G、-148C／T、-249C／T、-455G／A多态性的等位基因频率及其与血浆纤维蛋白原（fibrinogen，Fg）水平的关系。方法 用比浊法测定238名健康个体的血浆Fg浓度，用PCR-限制性片段长度多态性方法及测序法分析多态性基因型，并用协方差分析比较9个位点的基因型与血浆Fg水平的关系。结果 海南汉族人群αTaqⅠ、βBclⅠ、HinfⅠA／C、C448、βBsmAⅠG／C、＋1689T／G、-148C／T、-249C／T、-455G／A稀有位点的等位基因频率分别为0．445、0．239、0．134、0．235、0．273、0．241、0．265、0．441、0．254，9个位点之间存在连锁不平衡；在总人群中，-455GA和AA基因型、-148CT和TT基因型、αTaqⅠT1T1基因型组的血浆Fg水平比野生型组高（P值均〈0．01）；在男性人群中，-455GA和AA基因型、-148CT和TT基因型、αTaqⅠT1T1、αTaqⅠT1T2基因型组的血浆Fg水平比野生型组高（P值均〈0．01）。在女性人群中，携带稀有位点A^-455、T^-148、αTaⅠT1的基因型组与野生型组之间的血浆赡水平差异无统计学意义。结论 在9个多态性位点之间存在连锁不平衡；A^-455、T^-148、αTaqⅠT1位点与血浆Fg水平增高关联，β-Fg-455G／A、-148C／T及α-TaqⅠ多态性与男性血浆Fg水平关联。     

KIR2DL4基因的多态性与南方汉族白血病的相关性研究CSCD

目的探讨南方汉族人群白血病与KIR2DL4等位基因多态性的相关性。方法提取南方汉族急性淋巴细胞白血病（acute lymphoblastic leukemia,ALL）（n=283）、急性髓系白血病（acutemyeloid[eukemia,AML）（n=227）、慢性髓系白血病（chronic myeloid leukemia,CMI。）（n=80）患者和306名南方汉族随机正常志愿捐血者的DNA基因组,应用本实验室自行设计的引物对KIR2DL4基因的全部8个外显子进行测序分型,用Assign4．7分析软件判定基因型。用SPSS13．0统计软件分别对检出的每个KIR2DIA等位基因、10A型等位基因和9A型等位基因的检出比例分别进行差异显著性分析,并进行P值校准（Pc）。结果ALL、AML、CMI,患者和正常对照均检出5种等位基因：KIR2DIA＊001、＊005、＊006、＊008、＊011。ALL病例组与对照组的KIR2DI．4＊011等位基因检出比例、10A型KIR2DL4等位基因检出比例的差异有统计学意义（KIR2DL4＊011：OR=1．66,P=0．01;10A型K琥2DIA：OR=0．42,P=0．03）,但尸值经过校准后,差异均无统计学意义（Pc≥O．05）。AML、CML病例组分别与对照组检出的各个KIR2DL4等位基因、10A型等位基因和9A型等位基因的检出比例进行比较,组间比较差异均无统计学意义（P〉0．05、Pc〉0．05）。结论南方汉族ALL、AML、CML白血病与KIR2DL4等位基因多态性无显著关联。     

IFN-γ基因多态性与小儿哮喘的相关性

目的探讨IFN-γ基因多态性、等位基因在儿童哮喘发病机理中的意义。方法采用PCR-SSP方法对30例小儿哮喘病儿及26例非哮喘呼吸道疾病患儿作IFN-γ基因多态性分析。结果30例哮喘组IFN-γ基因型中,T/T1例,T/A7例,A/A22例,26例非哮喘组IFN-γ基因型中,T/T7例,T/A11例,A/A8例。χ2=11.696,P<0.005,两组IFN-γ基因型有明显差异。哮喘组IFN-γ等位基因T和A的频率为15%和85%,非哮喘组IFN-γ等位基因T和A的频率为51.9%和48.1%,哮喘组IFN-γ等位基因A的频率比非哮喘组IFN-γ等位基因A高,相对危险度0.191,95%可信度区间0.078-0.466,χ2=14.416,P<0.005,两组IFN-γ等位基因频率有明显差异。结论本研究证实小儿哮喘易感性与IFN-γ基因启动子多态性相关联。     

云南汉族人群HLA-B基因多态性与类风湿性关节炎的相关性研究

目的 探讨HLA-B基因多态性与类风湿性关节炎(rheumatoid arthritis,RA)的关联性.方法 采用DNA测序和序列特异性引物聚合酶链式反应(polymerase chain reaction-sequencespecific primer,PCR-SSP)方法检测云南汉族中271例类风湿性关节炎患者和264例正常人群的HLA-B基因多态性并进行关联性分析.结果 女性类风湿性关节炎患者的HLA-B*40基因频率(8.84％)明显低于女性对照组(18.33％)(P=0.000),HLA-B*51基因频率(9.53％)明显高于对照组(2.83％)(P=0.000),HLA-B*48基因频率(0.23％)明显低于对照组(2.33％)(P=0.007),差异均有统计学意义.HLA-B*40、HLA-B*51、HLA-B* 48的基因频率在男性类风湿性关节炎患者和男性对照中的分布无统计学差异(P值分别为0.535、0.691、0.289).结论 云南汉族人群中HLA-B基因分布存在多态性.HLA-B基因多态性与云南汉族人群女性类风湿性关节炎的发病相关,HLA-B*51可能是易感基因,HLA-B*40、HLA-B* 48可能是保护性等位基因.     

Isolation and functional analysis of circulating dendritic cells from hepatitis C virus (HCV) RNA-positive and HCV RNA-negative patients with chronic hepatitis C: role of antiviral therapy

Hepatitis C virus (HCV) RNA has been localized in antigen-presenting dendritic cells (DCs) from patients with chronic hepatitis C (CHC). DCs from patients with CHC also exhibit impaired functional capacities. However, HCV RNA in DCs and functional impairment of DCs in CHC might be independent or interrelated events. Moreover, the impact of antiviral therapy on the functions of DCs in CHC is not well documented. In order to address these issues, we took advantage of antiviral therapy in these patients. Ten patients with CHC, expressing HCV RNA in circulating DCs, became negative for HCV RNA in circulating DCs after therapy with interferon-alpha and ribavirin for 4 weeks. The functions of DCs from HCV RNA+ patients (isolated before antiviral therapy) and HCV RNA- patients (isolated 4 weeks after antiviral therapy) were compared in allogenic mixed leucocyte reactions. In comparison to circulating DCs from normal control subjects, DCs from HCV RNA+ patients had a significantly decreased capacity to stimulate allogenic T lymphocytes (P < 0.01) and produce interleukin-12 (P < 0.05). However, the allostimulatory capacity of circulating DCs from HCV RNA- patients was several-fold higher compared to that of HCV RNA+ DCs from the same patient. DC from HCV RNA- patients also produced significantly higher levels of interleukin-12 compared to HCV RNA+ DCs from the same patient (P < 0.01). Taken together, this study is the first to provide experimental evidence regarding the impact of HCV RNA and antiviral therapy on the function of DCs in patients with CHC.     

加强慢性乙型肝炎的抗病毒治疗

我国“慢性乙型肝炎防治指南”指出:“慢性乙型肝炎治疗主要包括抗病毒、免疫调节、抗炎保肝、抗纤维化和对症治疗,其中抗病毒治疗是关键,只要有适应证,且条件允许,就应进行规范的抗病毒治疗[1]。”但据调查,我国仅有19%慢性乙型肝炎患者接受抗病毒治疗;45%医务人员不知道慢性乙型肝炎规范化抗病毒治疗;73%医师仅用中成药和保肝降酶药治疗慢性乙型肝炎患者;38%慢性乙型肝炎患者轻信虚假广告。因此,多数慢性乙型肝炎患者未能得到及时、规范的抗病毒治疗,从而延误了病情,甚至发展成为肝硬化和肝细胞癌(HCC)。值得指出的是:我国一方面是大多…     

Current antiviral therapy for chronic hepatitis B

During the past decade, major breakthroughs have been achieved in treatment of chronic hepatitis B. Currently, three therapeutic agents are approved for chronic hepatitis B: interferon-alpha, lamivudine and adefovir dipivoxil. In patients with HBeAgpositive chronic hepatitis B, all of these drugs achieve HBeAg loss (24-33%) and anti-HBe seroconversion (12-30%) rates that are superior to those observed in untreated controls. Interferon-alpha has several drawbacks, such as the parenteral administration and the development of frequent and potentially serious side effects. Lamivudine is a safe drug with rare and generally mild side effects. Lamivudine induces an initial virological remission in 70-90% of patients, but only 30-40% of patients remain in remission after the third year due to progressively increasing viral resistance. The main advantage of adefovir dipivoxil is the rare emergence of resistance, which has been identified in less than 2% of patients at 2 yr of treatment. Adefovir is also effective against lamivudine-resistant strains. This review will focus on the natural history and recently gained knowledge on the treatment of chronic hepatitis B.     

Mannan-binding lectin MBL2 gene polymorphism in chronic hepatitis C: association with the severity of liver fibrosis and response to interferon therapy

Hepatitis C virus (HCV) is a major cause of hepatic disease and of liver transplantation worldwide. Mannan-binding lectin (MBL), encoded by the MBL2 gene, can have an important role as an opsonin and complement activating molecule in HCV persistence and liver injury. We assessed the MBL2 polymorphism in 102 Euro-Brazilian patients with moderate and severe chronic hepatitis C, paired for gender and age with 102 HCV seronegative healthy individuals. Six common single nucleotide polymorphisms in the MBL2 gene, three in the promoter (H/L, X/Y and P/Q) and three in exon 1 (A, the wild-type, and B, C or D also known as O) were evaluated using real-time polymerase chain reaction with fluorescent hybridization probes. The concentration of MBL in plasma was measured by enzyme-linked immunosorbent assay. The frequency of the YA/YO genotype was significantly higher in the HCV patients compared with the controls (P = 0.022). On the other hand, the genotypes associated with low levels of MBL (XA/XA, XA/YO and YO/YO) were decreased significantly in the patients with severe fibrosis (stage F4), when compared with the patients with moderate fibrosis (stage F2) (P = 0.04) and to the control group (P = 0.011). Furthermore, MBL2 genotypes containing X or O mutations were found to be associated with non-responsiveness to pginterferon and ribavirin treatment (P = 0.023). MBL2 polymorphisms may therefore be associated not only with the development of chronic hepatitis C, but also with its clinical evolution and response to treatment.     

Longitudinal study of hepatitis C viremia in chronic hepatitis C

Serial serum samples from 20 untreated patients with chronic hepatitis C virus (HCV) infection were tested for HCV RNA by a nested polymerase chain reaction assay using primers from the highly conserved 5′ noncoding region to determine the relationship between hepatitis C viremia and the activity of liver disease during the natural course of chronic HCV infection. Semiquantitation of serum HCV RNA level was achieved by testing serial 10-fold dilutions of RNA extracts to determine the end-point titer. All the patients were HCV RNA positive at presentation. There was a poor correlation between the initial HCV RNA titer and serum transaminase levels. All patients except one were persistently HCV RNA positive during a follow-up period of 1.5-15 years, although 17 (85%) had periods of normal or near-normal transaminase levels. There was no correlation between changes in the serum transaminase levels and HCV RNA titer. Patients with chronic HCV infection have persistent viremia despite fluctuations in ALT levels.     

Dynamics of serum hepatitis C virus load and quasispecies complexity during antiviral therapy in patients with chronic hepatitis C.

BACKGROUND: Hepatitis C virus (HCV) infection is a dynamic process during which viral genetic variants continuously develop as a result of the virus adaptation to the host's immune system. The level of viremia and the complexity of the hypervariable region 1 (HVR 1) quasispecies of hepatitis C virus during antiviral therapy reflect the dynamic balance between the viral and host components in response to therapy. OBJECTIVE: The aim of the study was to evaluate the dynamics of HCV viremia and the complexity of the HVR 1 quasispecies during the induction phase of a triple combination therapy regimen in nonresponders to earlier anti-HCV treatment. STUDY DESIGN: Ten patients with chronic hepatitis C undergoing antiviral combination therapy with interferon-alpha, ribavirin, and amantadine were studied. The serum HCV RNA level was monitored by a quantitative RT-PCR assay up to 3 months after start of treatment. The HVR 1 quasispecies complexity was analysed by an "in house" nested RT-PCR mediated single-strand conformation polymorphism (SSCP) assay. RESULTS: Baseline serum HCV RNA levels ranged from 1.94x10(6) to 5.53x10(6) copies/ml. In all patients, HCV subtype 1b was found. At the start of therapy, the SSCP assay revealed a high complexity pattern (at least six SSCP bands) in all patients. None of the patients responded within 4 weeks of treatment, however, the serum HCV RNA level decreased by one to two logs in eight patients. At week 4 after start of treatment, there was a decrease of SSCP bands in five patients. In four patients, SSCP bands remained unchanged and in one patient SSCP bands increased. At month 3 after start of treatment, serum HCV RNA was not detectable in one patient. CONCLUSION: Because of the low number of patients involved in this study, prediction of therapeutical success based on the quasispecies complexity was not possible. Larger studies are urgently needed.     

Prediction of the efficacy of antiviral therapy for hepatitis C virus infection by an ultrasensitive RT-PCR assay

The efficacy of interferon therapy for hepatitis C virus (HCV) infection improved remarkably. However, virologic relapse occurs in a substantial proportion of patients with virologic response (defined as an HCV RNA level below 50 IU/ml at the end-of-treatment). A highly sensitive RT-nested PCR assay capable of detecting almost a single copy of HCV RNA and a real-time RT-PCR assay to quantify HCV RNA down to 120 copies per ml were developed. The RT-nested PCR assay showed that 1 IU of HCV RNA is equivalent to 12.2 copies. For 28 patients with virologic response (12 relapsers and 16 sustained virologic responders), week-4 and end-of-treatment plasma samples were retested. At week 4, HCV RNA was detected by the RT-nested PCR and qualitative COBAS Amplicor HCV version 2.0 in 8/9 (89%) and 6/9 (67%) samples from relapsers, and in 4/16 (25%) and 2/16 (13%) samples from sustained virologic responders, respectively. End-of-treatment samples with HCV-negative by the qualitative COBAS Amplicor were positive by the present assay in 4/12 (25%) of relapsing patients and 0/16 (0%) of sustained virologic responders. The viral levels detected by the present assay in the Amplicor-negative samples were 3.5-17.3 copies/ml, which is below the detection limit of COBAS Amplicor. In conclusion, the highly sensitive RT-nested PCR assay can predict sustained virologic response at week 4 and virologic relapse at the end-of-treatment more accurately than COBAS Amplicor, suggesting its usefulness in monitoring antiviral therapy for HCV infection.     

Early viraemia clearance during antiviral therapy of chronic hepatitis C improves dendritic cell functions

Plasma and cellular HCV RNA and core antigen were tested in monocyte-derived DC (MDDC) from chronic hepatitis C patients undergoing treatment with peg-interferon α2b/ribavirin. DC allostimulatory capacity, HCV-specific T-cell reactivity and IL-12 production were measured at baseline and treatment week (TW)12. Using DC and autologous CD4⁺T-cells, obtained at baseline and TW12, we performed cross-over experiments to determine the relative role of DC and/or T-cells for impaired immune reactivity to HCV. HCV RNA and HCV core plasma levels had an impact on DC phenotype and allostimulatory capacity. In contrast, HCV genome/core protein, although detectable in DC from some patients had no effect on DC function. Antiviral immunity at TW12 was not improved in patients who remained HCV RNA positive, while early viraemia clearance (TW12) improved antiviral responses. The cross-over experiment revealed that changes in DC, rather than CD4⁺T cells have a major role for enhanced anti-HCV responses.     

miR-196a-5p抑制小鼠胚胎干细胞的自我更新

目的 研究miR-196a-5p在小鼠胚胎干细胞(mESC)自我更新中的功能.方法 定量PCR法确定miR-196a-5p在mESC早期分化过程中的表达.在胚胎干细胞中过表达miR-196a-5p类似物,通过集落形成实验、细胞周期分析、碱性磷酸酶染色和Oct4染色确定miR-196a-5p过表达对mESC自我更新及增殖的影响.结果 miR-196a-5p在mESC早期分化过程中表达上升(P＜0.05),在mESC中过表达miR-196a-5p类似物后,ESC的集落形成及增殖能力被明显抑制(P＜0.01),碱性磷酸酶活性下降,Oct4蛋白水平也出现明显下降.结论 miR-196a-5p具有抑制mESC自我更新的能力,在mESC早期分化过程中可能发挥重要作用.