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1.
Chinese Journal of Virology ; (6): 14-17, 2015.
Article in Chinese | WPRIM | ID: wpr-280302

ABSTRACT

In order to investigate the mutation of HBV polymerase gene reverse transcription conserved region (P region) in chronic hepatitis B (CHB) patients, 212 CHB patients who took antiretroviral treatment with nucleotide analogues were chosen. The drug resistance mutations of HBV P region and HBV genotype were detected by Pyrosequencing. Sequence analysis showed that the drug resistance sites of HBV P region located at sites 173; 180; 181; 184; 204; 236 and 250. The main site of HBV P region drug resistance was 204 and 180, accounting for 35.8% and 23.5%, respectively. There were significant differences in the mutation rate of site 180 among different age groups. There were also significant differences in the mutation rate of site 204 among younger than 30 age group, 41 to 50 age group and 51 to 60 age group. (P < 0.05, P < 0.01). The mutation rate of site 180 combined with site 204 was 66.6%. The mutation rate of site 181 combined with site 236 was 23.3%. The age of C genotype infected patients was significantly older than B genotype infected patients (P < 0.01). M204V/I mutation mostly existed in the form of joint L180M mutation, the mutation rate was age-related. The detection of HBV genotypes and drug resistance sites of HBV P region have important clinical implications for the treatment and prognosis of patients with CHB.


Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Antiviral Agents , Pharmacology , China , Drug Resistance, Viral , Gene Products, pol , Genetics , Genotype , Hepatitis B virus , Classification , Genetics , Hepatitis B, Chronic , Drug Therapy , Virology , Mutation, Missense
2.
Clinical and Molecular Hepatology ; : 193-199, 2015.
Article in English | WPRIM | ID: wpr-157210

ABSTRACT

Hepatitis B virus (HBV) is the prototype of hepatotropic DNA viruses (hepadnaviruses) infecting a wide range of human and non-human hosts. Previous studies with duck hepatitis B virus (DHBV) identified duck carboxypeptidase D (dCPD) as a host specific binding partner for full-length large envelope protein, and p120 as a binding partner for several truncated versions of the large envelope protein. p120 is the P protein of duck glycine decarboxylase (dGLDC) with restricted expression in DHBV infectible tissues. Several lines of evidence suggest the importance of dCPD, and especially p120, in productive DHBV infection, although neither dCPD nor p120 cDNA could confer susceptibility to DHBV infection in any cell line. Recently, sodium taurocholate cotransporting polypeptide (NTCP) has been identified as a binding partner for the N-terminus of HBV large envelope protein. Importantly, knock down and reconstitution experiments unequivocally demonstrated that NTCP is both necessary and sufficient for in vitro infection by HBV and hepatitis delta virus (HDV), an RNA virus using HBV envelope proteins for its transmission. What remains unclear is whether NTCP is the major HBV receptor in vivo. The fact that some HBV patients are homozygous with an NTCP mutation known to abolish its receptor function suggests the existence of NTCP-independent pathways of HBV entry. Also, NTCP very likely mediates just one step of the HBV entry process, with additional co-factors for productive HBV infection still to be discovered. NTCP offers a novel therapeutic target for the control of chronic HBV infection.


Subject(s)
Animals , Carboxypeptidases/genetics , Gene Products, pol/genetics , Heparan Sulfate Proteoglycans/metabolism , Hepatitis B virus/physiology , Hepatocytes/metabolism , Organic Anion Transporters, Sodium-Dependent/antagonists & inhibitors , RNA Interference , Symporters/antagonists & inhibitors , Viral Envelope Proteins/metabolism , Virus Internalization
3.
Chinese Journal of Virology ; (6): 636-644, 2014.
Article in Chinese | WPRIM | ID: wpr-280315

ABSTRACT

Hepatitis B virus (HBV) is a major cause of chronic liver disease, and frequently results in hepatitis, cirrhosis, and ultimately hepatocellular carcinoma. HBV polymerase (Pol) is an essential viral protein that is important for HBV replication and might be involved in the development of hepatocellular carcinoma. Protein-protein interactions appears to be crucial for its role. The aim of this study was to screen and identify the proteins that interact with Pol using a co-immunoprecipitation-based LC-MS/MS identification technique. The HBV Pol gene was amplified by polymerase chain reaction (PCR) and cloned into pCDNA3.1(+). The recombinant plasmid pCDNA3. 1(+)-Pol-flag was transfected into HeLa cells. Liquid chromatography and tandem mass spectrometry (LC-MS/MS) identified 45 proteins that co-immunoprecipitated with flag-tagged HBV Pol. Eleven of these have previously been reported as proteins that interact with HBV Pol. A proof-of-concept-based Ingenuity Pathway Analysis (IPA, www.ingenuity.com) was used to characterize the functions and pathways of these 45 identified proteins and HBV Pol. Among these proteins, four proteins may play a role in three major molecular cellular networks, and are therefore worthy of further investigation.


Subject(s)
Humans , Cell Line, Tumor , Chromatography, Liquid , Methods , Gene Products, pol , Chemistry , Genetics , Metabolism , Hepatitis B , Genetics , Metabolism , Virology , Hepatitis B virus , Chemistry , Genetics , Immunoprecipitation , Methods , Protein Interaction Maps , Software , Tandem Mass Spectrometry , Methods
4.
Chinese Journal of Virology ; (6): 713-720, 2014.
Article in Chinese | WPRIM | ID: wpr-280305

ABSTRACT

Clinically being applied treatment against chronic hepatitis has three limitations: low response rates, severe adverse effects and a high rate of drug resistance. Hence, novel targets for antiviral therapy need to be developed so as to provide an armory of different strategies. During the replication of hepatitis B virus, the interaction of viral polymerase (P protein, also called P) and epsilonRNA is indispensable for the initiation of reverse transcription via protein priming and the pregenome RNA (pgRNA) packaging. Three strategies are currently developed for blocking P-epsilon interaction: heat shock protein inhibitors, epsilonaptamers and chemical compounds for blocking formation of P-epsilon complex. Previously, our group has for the first time worldwide in vitro screened several aptamers, which are able to interfere with the P-epsilon interaction. A strong inhibition against HBV was observed in vitro and in vivo experiments, respectively. In conclusion, the so far developed chemicals suppressing the P-epsilon interaction may bypass or overcome the viral resistance problems during clinic treatment and represent a highly attractive option for therapeutic intervention.


Subject(s)
Animals , Humans , Gene Expression Regulation, Viral , Gene Products, pol , Genetics , Metabolism , Hepatitis B , Therapeutics , Virology , Hepatitis B virus , Genetics , Physiology , RNA, Viral , Genetics , Metabolism , Virus Replication
5.
Journal of Biomedical Engineering ; (6): 995-1013, 2012.
Article in Chinese | WPRIM | ID: wpr-246518

ABSTRACT

Hepatitis B virus (HBV) infection disrupt the innate immunity response, which may play an important role in the chronic mechanism, while retinoic acid-induced gene I (RIG-I) mediated signaling pathway is one of the most important channel in the innate immunity. HBx and HBV polymerase may disrupt RIG-I mediated signaling pathway. The recent advances about HBV and RIG-I are reviewed in this article.


Subject(s)
Humans , DEAD Box Protein 58 , DEAD-box RNA Helicases , Metabolism , Gene Products, pol , Metabolism , Hepatitis B , Allergy and Immunology , Immunity, Innate , Allergy and Immunology , Signal Transduction , Trans-Activators , Metabolism
6.
Pakistan Journal of Pharmaceutical Sciences. 2012; 25 (2): 349-352
in English | IMEMR | ID: emr-128888

ABSTRACT

Hepatitis B virus [HBV] affects more than 350 million people worldwide and is a leading cause of morbidity and mortality in developing countries like Pakistan. Lamivudine has potential to inhibit hepatitis B virus [HBV] replication but long term lamivudine treatment results in mutations in YMDD region of HBV, making this therapy ineffective. In this study, we have optimized a polymerase chain reaction-restriction fragment length polymorphism [PCR-RFLP] based protocol to detect two mutations in HBV DNA polymerase gene [at codon 528 and 552] in chronic hepatitis patients, without any prior lamivudine treatment. HBV genome was extracted and tested by PCR-RFLP for detection of mutations in polymerase gene. Variations in HBV genome were not detected in enrolled patients confirming that lamivudine can be used to treat chronic Hepatitis B in these patients. Several studies have reported the natural occurrence of mutation in YMDD motif of polymerase gene in chronic hepatitis B patients, not treated with lamivudine, but these mutants were not detected in Pakistani lamivudine-untreated chronic hepatitis B patients


Subject(s)
Humans , Male , Female , Hepatitis B virus , Lamivudine , Polymorphism, Restriction Fragment Length , Polymerase Chain Reaction , Mutation , Gene Products, pol
7.
Chinese Journal of Experimental and Clinical Virology ; (6): 342-344, 2011.
Article in Chinese | WPRIM | ID: wpr-246245

ABSTRACT

<p><b>OBJECTIVE</b>To analyze the mutation patters of HBV P gene and genotyping of heptitis B virus in patients with chronic hepatitis B (CHB) after the emergence of drug-resistance during lamivudine (LAM) therapy.</p><p><b>METHODS</b>LAM-resistant mutations and genotype of HBV were dectected in patients with LAM-resistant CHB in our hospital from Sep. 2008 to June. 2010.</p><p><b>RESULT</b>107 patients had 8 mutation patterns. YMDD mutations happened in 100%, only YMDD mutation were 43 patients, while others were YMDD combined with rtL180M mutations; the HBV genotype among 107chronic hepatitis was mainly B (25.2%) and C (73.8%) and only 1 patient was happend B and C mixed infection. Genetype C was mainly YMDD combined with rtL180M mutations pattern, the rate is 60.7% (48/79); while genetype B was mainly rtM204 mutation pattern, the rate is 66.7% (18/27); there were significant difference between the genetype B and C in mutation pattern (chi2 = 8.4, 7.2, respectively, P < 0. 01).</p><p><b>CONCLUSION</b>YMDD mutation is the major mutation pattern of HBV P gene after emergence of LAM-resistance. Genotypes of hepatitis B virus can determine the related mulation patterns of HBV P gene.</p>


Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Young Adult , Antiviral Agents , Therapeutic Uses , Drug Resistance, Viral , Gene Products, pol , Genetics , Genotype , Hepatitis B virus , Genetics , Hepatitis B, Chronic , Drug Therapy , Virology , Lamivudine , Therapeutic Uses , Mutation
8.
Journal of Southern Medical University ; (12): 686-689, 2011.
Article in Chinese | WPRIM | ID: wpr-332574

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the function of hepatitis B virus polymerase (HBV Pol) in the viral life cycle by screening the proteins interacting with HBV polymerase.</p><p><b>METHODS</b>The HBV Pol gene was constructed into the pGBKT7 vector. GAL4 yeast two-hybrid system was used to screen the human liver cDNA library to obtain proteins which interacted with HBV Pol. GST-pull down assay was applied to confirm the protein interactions.</p><p><b>RESULTS</b>Ubiquitously expressed transcript (UXT) was selected by the yeast two-hybrid system. GST-pull down assay confirmed the in vitro interaction between HBV Pol and UXT.</p><p><b>CONCLUSIONS</b>UXT is a potential interactor of HBV Pol, and this protein interaction may provide clues of the function of HBV Pol in HBV life cycle.</p>


Subject(s)
Humans , Gene Products, pol , Metabolism , Hepatitis B virus , Neoplasm Proteins , Metabolism , Protein Interaction Mapping , Two-Hybrid System Techniques , Virus Replication
9.
Chinese Journal of Hepatology ; (12): 342-345, 2009.
Article in Chinese | WPRIM | ID: wpr-310090

ABSTRACT

<p><b>OBJECTIVE</b>To analyze mutation patterns in the RT region of hepatitis B virus (HBV) P gene in patients treated with nucleoside or nucleotide analogs.</p><p><b>METHODS</b>Viral DNA was extracted from 227 serum samples of chronic hepatitis B patients from September, 2005 to March, 2007. The RT region of HBV P gene was PCR-amplified and sequenced.</p><p><b>RESULTS</b>Known resistant mutations were found in 111 cases (48.9%) among 227 samples, 75 cases with clear therapy history. Novel mutations, including A222T, L229V and S256C, were also found. The incidence of multi-drug resistance in patients sequentially treated with lamivudine and adefovir was 25% (4/16), and none of the patients treated with lamivudine plus adefovir in combination shown multi-drug resistance.</p><p><b>CONCLUSION</b>The patterns of mutation is complex in nucleotide analogue treated patients. Switching to adefovir in lamivudine resistant patients may lead to multi-drug resistance. Novel mutations identified in this study need further investigation.</p>


Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Antiviral Agents , Pharmacology , Therapeutic Uses , DNA Mutational Analysis , DNA, Viral , Genetics , Drug Resistance, Viral , Gene Products, pol , Genetics , Genes, Viral , Genetic Variation , Hepatitis B virus , Genetics , Hepatitis B, Chronic , Drug Therapy , Genetics , Virology , Reverse Transcriptase Inhibitors , Pharmacology , Therapeutic Uses , Reverse Transcriptase Polymerase Chain Reaction , Methods
10.
Chinese Journal of Virology ; (6): 339-343, 2009.
Article in Chinese | WPRIM | ID: wpr-297951

ABSTRACT

A quantitative real-time PCR assay was developed to measure the proviral load of human T-lymphotropic virus type I (HTLV-I) in peripheral blood. The technology utilizes special primers and Taqman MGB fluorescence probe to measure amplification products from the gag-pro-pol polyprotein gene of HTLV-I. HTLV-I copy number was normalized to the amount of cellular DNA by quantitation of the beta-actin gene, The amplification system was sensitive to detect 5 copy/microL. The standard curve had a good linearity when the quantity for the gene was between 10(3) and 10(7) copy/microL (R2 = 0.999). Good reproducibility was observed in each intra- and inter-assay. We also measured proviral load in peripheral blood in 12 HTLV-I seropositive former blood donors. Proviral load for HTLV-I infected donors ranged from 0.015 to 12.819 copy/cell in WBC with the mean of 3.116 copy/cell.


Subject(s)
Humans , Gene Products, gag , Genetics , Gene Products, pol , Genetics , Human T-lymphotropic virus 1 , Genetics , Molecular Probes , Polymerase Chain Reaction , Methods , Viral Proteins , Genetics
11.
Korean Journal of Blood Transfusion ; : 93-98, 2009.
Article in Korean | WPRIM | ID: wpr-160022

ABSTRACT

BACKGROUND: Since 2004, the donors showing hepatitis B surface antigen (HBsAg) reactive results have been registered in the donor deferral registry (DDR). Some of them can donate blood as eligible donors by passing the reentry tests. We evaluated the results of the reentry tests during 1 year. METHODS: We tested the samples from 2,230 deferred donors with HBsAg reactivity and 1,668 samples from donors who had a past history of hepatitis B and all these patients required reentry tests. Hepatitis B surface antigen, hepatitis B core antibody and hepatitis B surface antibody were tested for by using ARCHITECT HBsAg (Abbott, Wiesbaden, Germany), ARCHITECT anti-HBc (Abbott), and ARCHITECT anti-HBs (Abbott) and using an ARCHITECT i2000SR (Abbott). Hepatitis B virus DNA was tested for by performing HBV Polymerase Chain Reaction (PCR) with a COBAS AMPLICOR HBV MONITOR TEST (Roche Molecular Systems Inc., Branchburg, USA) and using a COBAS AMPLICOR (Roche Diagnostics, Basel, Switzerland). RESULTS: 894 (40.1%) of 2,230 the deferred donors and 880 (52.8%) of 1,668 donors who had a past history of hepatitis B were reentered as eligible donors. 1,171 (30.0%) of the 3,898 tested donors couldn't be released due to positive results on the anti-HBc test and 81.5% of them were also anti-HBs positive. CONCLUSION: The reentry test seems to be necessary to restore blood donors. But it was considered that the donor showing a reactive result for anti-HBc and a nonreactive result for HBsAg and HBV PCR can be released as eligible donors if the anti-HBs titer is higher than the reference value.


Subject(s)
Humans , Blood Donors , DNA , Gene Products, pol , Hepatitis , Hepatitis B , Hepatitis B Surface Antigens , Hepatitis B virus , Organothiophosphorus Compounds , Polymerase Chain Reaction , Tissue Donors
12.
Indian J Med Microbiol ; 2008 Oct-Dec; 26(4): 372-4
Article in English | IMSEAR | ID: sea-53969

ABSTRACT

In north India the number of paediatric cases with acquired immunodeficiency syndrome (AIDS) is on the rise. Most drug combinations used for treatment of AIDS incorporate nevirapine, resistance to which develops very fast if given singly or because of unplanned interruptions. This paper investigates presence of mutations at codon 103 and codon 215 of the HIV pol gene causing resistance to nevirapine and zidovudine (AZT) respectively in 25 children with AIDS. Mutations T215Y and K103N were detected by a nested cum amplification refractory mutation system polymerase chain reaction (ARMS PCR) and the results were confirmed by direct sequencing in five randomly selected cases. Nineteen patients had received nevirapine containing regimen and six were drug naive. Mutation K103N was observed in 56% (14/25) of the children while mutation T215Y was found in none. Two of the six drug naïve children also showed K103N mutation. Thus, Indian children drug naïve or treated with nevirapine containing regimens show a high rate of mutation conferring resistance to nevirapine which calls for a judicious use of nevirapine both in antenatal and postnatal setting.


Subject(s)
Anti-HIV Agents/pharmacology , Child , Child, Preschool , DNA, Viral/genetics , Drug Resistance, Viral/genetics , Female , Gene Products, pol/genetics , Genes, pol , HIV Infections/drug therapy , HIV-1/drug effects , Humans , Infant , Male , Mutation , Nevirapine/pharmacology , Polymerase Chain Reaction/methods , Reverse Transcriptase Inhibitors/pharmacology , Zidovudine/pharmacology
13.
Journal of Southern Medical University ; (12): 729-730, 2008.
Article in Chinese | WPRIM | ID: wpr-280109

ABSTRACT

<p><b>OBJECTIVE</b>To explore the characteristics of mutation in HBV polymerase (P) gene reverse transcriptase region (RT region) in lamivudine-resistant chronic hepatitis B (CHB) patients.</p><p><b>METHODS</b>This study involved 115 CHB patients who developed clinical resistance to lamivudine. Direct sequencing of the PCR products was used to detect lamivudine genotypic resistance.</p><p><b>RESULTS</b>Lamivudine resistant mutation was detected in 103 patients, and the major mutations included rtL180M+rtM204V and rtM204I, accounting for 58.3% and 22.3%, respectively. Other resistant substitutions included rtL80V/I, rtT184S, and rtA200V, and combined mutation of triple resistant substitutions was detected in HBV RT region of 5 patients by direct sequencing.</p><p><b>CONCLUSION</b>For lamivudine-treated patients, combined mutation at the sites other than rtL180 and rtM204 in HBV P gene should also be detected for drug resistance evaluation.</p>


Subject(s)
Humans , Anti-HIV Agents , Therapeutic Uses , Drug Resistance, Viral , Genetics , Gene Products, pol , Genetics , Hepatitis B virus , Genetics , Hepatitis B, Chronic , Drug Therapy , Virology , Lamivudine , Therapeutic Uses , Mutation
14.
The Korean Journal of Gastroenterology ; : 85-92, 2007.
Article in Korean | WPRIM | ID: wpr-15079

ABSTRACT

BACKGROUND/AIMS: To develop a novel treatment method for hepatitis B virus (HBV) infection, we aimed to make a human monoclonal antibody inhibiting reverse transcriptase (RT) activity of P protein which was important in HBV replication by using phage display technique. Therefore, we analysed the usability of human monoclonal antibody as a protein based gene therapy. METHODS: Reverse transcriptase/polymerase (RT/POL) functional motif of P protein of HBV was cloned in pMAL-c vector and expressed as maltose binding fusion protein form. The RT/POL recombinant protein (pMRT/POL) was purified by amylose resin column. Using human single chain Fv phage antibody library with 1.1x10(10) size, human antibody against pMRT/POL was selected with BIAcore panning. Selected antibody fragments were analyzed for the activity of RT inhibition. Finally, they were analyzed for the affinity with BIAcore and the complementarity determining regions with nucleotide sequencing. RESULTS: pMRT/POL recombinant protein expressed in E. coli showed RT activity, 1microgram of recombinant protein had an activity equivalent to 5 unit of MMLV RT. By BIAcore panning, we could select 3 clones; POL-A5, POL-B8 and POL-B12. Each clone's RT inhibiting activity were 52-82%, affinity against antigen were 8.15x10(-8) M to 1.75x10(-6) M. CONCLUSIONS: Human monoclonal antibodies produced in this study showed low affinity, but efficiently inhibited the activity of RT in vitro. If POL-A5, POL-B8, and POL-B12 can be converted to intracellular antibody form, it can be used for protein-based gene therapy by inhibiting the replication through the neutralization of polymerase protein of HBV.


Subject(s)
Humans , Antibodies, Monoclonal/biosynthesis , Complementarity Determining Regions/chemistry , Gene Products, pol/antagonists & inhibitors , Genetic Vectors , Hepatitis B virus/enzymology , Peptide Library , RNA-Directed DNA Polymerase/genetics , Recombinant Fusion Proteins/biosynthesis , Reverse Transcriptase Inhibitors/chemistry
15.
Invest. clín ; 47(1): 27-34, mar. 2006. graf
Article in English | LILACS | ID: lil-449297

ABSTRACT

Se estudiaron pacientes seropositivos para el virus de inmunodeficiencia humana tipo 1 (VIH-1) con y sin tratamiento, con el fin de determinar el polimorfismo y la prevalencia de mutaciones de resistencia a la terapia antirretroviral. El material genético viral fue extraído a partir de células mononucleares de sangre periféricas (ADN) y del plasma (ARN) de 30 pacientes. Se amplificaron 2 regiones del gen Pol, Transcriptasa Reversa (TR) y Proteasa (Pr) y el gen de envoltura (Env) por medio de la técnica de PCR y se obtuvo la secuencia genómica de los productos. Todos los aislados analizados pertenecieron al subtipo B. No se observaron mutaciones primarias asociadas a resistencia a inhibidores de Pr pero sí un alto porcentaje (86 por ciento, 19/22) de mutaciones no asociadas con resistencia sino a restitución de la capacidad replicativa de cepas mutantes (mutaciones secundarias). Se observó la presencia de mutaciones asociadas a resistencia a inhibidores nucleósidos de la TR (INTR) en 35 por ciento (6/17) de los pacientes sometidos a tratamiento, mientras que 12 por ciento (2/17) de ellos presentaron mutaciones de resistencia a inhibidores no nucleósidos de la TR (INNTR). Interesantemente, un paciente no tratado estaba infectado con una cepa que presentaba mutaciones primarias (7,7 por ciento); este resultado sugiere que podría ser importante plantearse el estudio local de determinación de resistencia genotípica en pacientes antes del tratamiento, con miras a minimizar fallas terapéuticas. Se requieren estudios adicionales para evaluar el rol de las mutaciones secundarias en el éxito de la infección viral


Subject(s)
Humans , Gene Products, pol , HIV-1 , Medicine , Venezuela
16.
Chinese Journal of Hepatology ; (12): 327-330, 2006.
Article in Chinese | WPRIM | ID: wpr-341372

ABSTRACT

<p><b>OBJECTIVE</b>To study variation features of the hepatitis B virus polymerase gene in chronic hepatitis B patients before and after lamivudine treatment.</p><p><b>METHODS</b>From the serum samples of five CHB patients both before and after 12 months' lamivudine treatment, HBV polymerase gene was amplified and positive DNA fragments were cloned into JM105. Twenty positive clones of every sample were checked with mismatched polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and YMDD variants were sequenced.</p><p><b>RESULTS</b>Among five patients after 12 months lamivudine treatment, M552I mutations in two patients with HBV DNA rebounding and D553G mutation in one non-responder were detected except in two patients with negative HBV DNA.</p><p><b>CONCLUSIONS</b>D553G mutation is probably one of the reasons which caused non-responsiveness to the lamivudine treatment. The mutations of YMDD motif that occurred after lamivudine treatment are caused by the induction of the drug.</p>


Subject(s)
Female , Humans , Male , Amino Acid Sequence , Base Sequence , Gene Products, pol , Genetics , Hepatitis B virus , Genetics , Hepatitis B, Chronic , Drug Therapy , Virology , Lamivudine , Therapeutic Uses , Molecular Sequence Data , Reverse Transcriptase Inhibitors , Therapeutic Uses
17.
Journal of Zhejiang University. Science. B ; (12): 664-667, 2005.
Article in English | WPRIM | ID: wpr-249153

ABSTRACT

<p><b>OBJECTIVES</b>To investigate the relationship between HBV (hepatitis B virus) polymerase gene 180 and 204 sites mutation and lamivudine resistance.</p><p><b>METHODS</b>One hundred forty-one patients with lamivudine resistance after lamivudine treatment and 60 chronic hepatitis B patients without lamivudine treatment were enrolled in this study. The serum HBV DNA mutation was analyzed by sequence detection via polymerase chain reaction (PCR). The sequences of the same patient were analyzed before and after lamivudine treatment.</p><p><b>RESULTS</b>One hundred and nine lamivudine resistance patients had HBV YMDD (tyrosine-methionine-aspartate-aspartate) mutation. Among them, 45 patients had rtL180M/M204V mutation (41.28%), 28 patients had rtL180M/M204I mutation (25.70%) and 36 patients had rtM204I mutation (33.02%). There were 6 patients with rtL180M mutation in 32 lamivudine resistance patients. Sixty chronic hepatitis patients without lamivudine treatment had no mutations.</p><p><b>CONCLUSIONS</b>HBV mutations, which play an important role in lamivudine resistance usually locate at polymerase gene 204 site; 180 site mutation was also observed in these patients. Evaluation of the anti-virus therapy by surveillance of the two sites mutations is of importance.</p>


Subject(s)
Humans , China , Epidemiology , DNA Mutational Analysis , Methods , DNA, Viral , Genetics , Drug Resistance, Viral , Gene Products, pol , Genetics , Genetic Predisposition to Disease , Epidemiology , Genetic Testing , Methods , Hepatitis B , Drug Therapy , Genetics , Hepatitis B virus , Genetics , Incidence , Lamivudine , Therapeutic Uses , Polymorphism, Genetic , Risk Assessment , Methods , Risk Factors
18.
Chinese Journal of Experimental and Clinical Virology ; (6): 162-164, 2005.
Article in Chinese | WPRIM | ID: wpr-333073

ABSTRACT

<p><b>OBJECTIVE</b>To establish a rapid specific method to identify the single-nucleotide polymorphisms (SNPs) of HBV polymerase gene region which are the methionine residue of the conserved YMDD motif.</p><p><b>METHODS</b>Two specific primers were designed to amplify interested gene region involved in SNPs which were also used as HBV DNA identification. Specific primers of SNaPshot were designed to detect 741A-G (YVDD), 743G-T (YIDD). The different fluorescent dye labeled ddNTP was used to further extend the strand of PCR product and was detected by ABI PRISM 310 Genetic Analyzer. Sera from 13 patients with chronic hepatitis B after lamivudine treatment were analyzed.</p><p><b>RESULTS</b>Aside from mutation of YMDD, there were mutations of 514C-A, 523C-A, 562T-A, 667C-A. The 13 samples were simultaneously tested with SNaPshot and DNA sequencing, the same results were obtained. The method of SNaPshot showed high specificity.</p><p><b>CONCLUSION</b>Mutation of YMDD results in the changes of ATG codon, and there are new ATG codon in the upper strand of YMDD. SNaPshot technique is rapid, specific and accurate for the SNPs monitoring of HBV DNA mutation during lamivudine therapy. Two samples were determined by SnaPshot technique, identifying the co-existence of the mixed wild type and mutant type HBV infection.</p>


Subject(s)
Humans , Antiviral Agents , Therapeutic Uses , Base Sequence , DNA, Viral , Blood , Genetics , Drug Resistance, Viral , Gene Products, pol , Genetics , Hepatitis B , Blood , Drug Therapy , Virology , Lamivudine , Therapeutic Uses , Polymorphism, Single Nucleotide , Sequence Analysis, DNA
19.
Journal of Zhejiang University. Science. B ; (12): 1182-1187, 2005.
Article in English | WPRIM | ID: wpr-263241

ABSTRACT

<p><b>OBJECTIVE</b>To study the clinical features of chronic hepatitis B (CHB) patients with tyrosine-methionine-aspartate-aspartate (YMDD) mutation after lamivudine therapy.</p><p><b>METHODS</b>This investigation was a retrospective study of 63 CHB patients with YMDD mutation during lamivudine therapy. Clinical data, including period and types of YMDD mutation; hepatitis B virus (HBV) DNA levels and alanine aminotransferase (ALT) levels before and after YMDD mutation were measured. YMDD mutation in the HBV DNA polymerase gene was determined using polymerase chain reaction (PCR) and direct sequencing. HBV DNA quantification was determined using real-time PCR. Relevant serum markers of HBV were measured. The follow-up period was 12 months after YMDD mutation.</p><p><b>RESULTS</b>YMDD mutation occurred 7-44 months (median, 21.5 months) after the start of lamivudine therapy. The majority of the cases (42/63, 66.6%) had YMDD mutants detected between 12 and 24 months. Four types of YMDD mutation were observed in this study, rtL180M/M204V mutation was the predominant type (26/63, 41.3%). A proportion of patients (16/63, 25.4%; 12/63, 19.1%) had higher HBV DNA levels and ALT levels (after mutation vs before mutation), respectively.</p><p><b>CONCLUSION</b>The majority of patients with YMDD mutants had similar or lower HBV DNA levels and ALT levels compared with baseline values. This subset of patients might have benefited from the continued lamivudine therapy. The patients with increased ALT and HBV DNA levels (breakthrough hepatitis) should benefit from the addition of a newer nucleotide analogue (e.g. adefovir).</p>


Subject(s)
Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Anti-HIV Agents , Therapeutic Uses , DNA Mutational Analysis , Gene Products, pol , Blood , Genetics , Hepatitis B, Chronic , Blood , Diagnosis , Drug Therapy , Genetics , Lamivudine , Therapeutic Uses , Mutation , Retrospective Studies , Treatment Outcome
20.
Chinese Journal of Hepatology ; (12): 368-369, 2004.
Article in Chinese | WPRIM | ID: wpr-259989

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the relationship between curative effect and incidence rate of the YMDD mutations of hepatitis B virus during lamivudine treatment for chronic hepatitis B patients twenty-four weeks.</p><p><b>METHODS</b>120 patients with chronic hepatitis B were treated with lamivudine (100 mg/d) over 24 weeks. The levels of serum ALT and HBV-DNA and clinical symptoms were detected at baseline and the 24th weeks after treatment. HBV-DNA YMDD mutation in 17 patients was detected by gene chips at baseline and the 24th weeks.</p><p><b>RESULTS</b>(1) Beside I case of YMDD/YVDD mutation was found before lamivudine treatment, 7 mutation were found after 24 weeks treatment, 2 with pure mutation strain, one of them was YIDD mutation, and the other was YVDD mutation; 2 and 3 others were YVDD/YMDD mutations and YMDD/YVDD mutations respectively. (2) The serum ALT and HBV DNA levels of YMDD mutation group showed no significantly change compared with normal group at baseline and 24th week.</p><p><b>CONCLUSION</b>The level of serum ALT and HBV DNA showed no significantly changes with the incidence of YMDD mutations at the 24 week treatment</p>


Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Amino Acid Motifs , Genetics , Antiviral Agents , DNA, Viral , Genetics , DNA-Directed DNA Polymerase , Genetics , Drug Resistance, Viral , Genetics , Gene Products, pol , Genetics , Genetic Variation , Hepatitis B virus , Genetics , Hepatitis B, Chronic , Drug Therapy , Virology , Lamivudine , Mutation
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