Hepatitis B virus pre-S2 start codon mutations in Indonesian liver disease patients

AIM: To identify the prevalence of pre-S2 start codon mutations and to assess their association with liver disease progression. METHODS: The mutations were identified by direct sequencing from 73 asymptomatic carriers, 66 chronic hepatitis (CH), 66 liver cirrhosis (LC) and 63 hepatocellular carcinoma (HCC) patients. Statistical significances were determined using Fisher's exact test, χ 2 test, and t -test analyses whenever appropriate. Pre-S mutation as a risk factor for advanced liver disease was estimated by unconditional logistic regression model adjusted with age, sex, and hepatitis B e antigen (HBeAg). P < 0.05 was considered significant. RESULTS: Mutation of the hepatitis B virus (HBV) pre-S2 start codon was found in 59 samples from 268 subjects (22.0%), with higher prevalence in patients with cirrhosis 27/66 (40.9%) followed by HCC 18/63 (28.6%), chronic hepatitis 12/66 (18.2%) and asymptomatic carriers 2/73 (2.7%) (P < 0.001). Logistic regression analysis showed that pre-S2 start codon mutation was an independent factor for progressive liver disease. Other mutations, at T130, Q132, and A138, were also associated with LC and HCC, although this was not statistically significant when adjusted for age, sex, and HBeAg. The prevalence of pre-S2 start codon mutation was higher in HBV/B than in HBV/C (23.0% vs 19.1%), whilst the prevalence of T130, Q132, and A138 mutation was higher in HBV/C than in HBV/B. The prevalence of pre-S2 start codon mutation was higher in LC (38.9%) and HCC (40.0%) than CH (5.6%) in HBeAg(+) group, but it was similar between CH, LC and HCC in HBeAg(-) group. CONCLUSION: Pre-S2 start codon mutation was higher in Indonesian patients compared to other Asian countries, and its prevalence was associated with advanced liver disease, particularly in HBeAg(+) patients.

Perilipin 2 inhibits replication of hepatitis B virus deoxyribonucleic acid by regulating autophagy under high-fat conditions

Hepatitis B virus(HBV)infection poses a global health concern without a definitive cure;however,antiviral medications can effectively suppress viral replication.This study delves into the intricate interplay between lipid metabo-lism and HBV replication,implicating molecular mechanisms such as the stearoyl coenzyme A desaturase 1 autophagy pathway,SAC1-like phosphatidylinositol phosphatase,and galectin-9 mediated selective autophagy of viral core proteins in regulating HBV replication.Within lipid droplets,perilipin 2(PLIN2)emerges as a pivotal guardian,with its overexpression protecting against autophagy and downregulation stimulating triglyceride catabolism through the autophagy pathway.This editorial discusses the correlation between hepatic steatosis and HBV replication,emphasizing the role of PLIN2 in this process.The study underscores the multifaceted roles of lipid metabolism,autophagy,and perilipins in HBV replication,shedding light on potential therapeutic avenues.

Locked nucleic acid real-time polymerase chain reaction method identifying two polymorphisms of hepatitis B virus genotype C2 infections,rt269L and rt269I

BACKGROUND The presence of two distinct hepatitis B virus(HBV)Pol RT polymorphisms,rt269L and rt269I,could contribute to the unique clinical or virological phenotype of HBV genotype C2.Therefore,a simple and sensitive method capable of identifying both types in chronic hepatitis B(CHB)patients infected with genotype C2 should be developed.AIM To develop a novel simple and sensitive locked nucleic acid(LNA)-real timepolymerase chain reaction(RT-PCR)method capable of identifying two rt269 types in CHB genotype C2 patients.METHODS We designed proper primer and probe sets for LNA-RT-PCR for the separation of rt269 types.Using synthesized DNAs of the wild type and variant forms,melting temperature analysis,detection sensitivity,and endpoint genotyping for LNA-RT-PCR were performed.The developed LNA-RT-PCR method was applied to a total of 94 CHB patients of genotype C2 for the identification of two rt269 polymorphisms,and these results were compared with those obtained by a direct sequencing protocol.RESULTS The LNA-RT-PCR method could identify two rt269L and rt269I polymorphisms of three genotypes,two rt269L types[‘L1’(WT)and‘L2’]and one rt269I type(‘I’)in single(63 samples,72.4%)or mixed forms(24 samples,27.6%)in 87(92.6%sensitivity)of 94 samples from Korean CHB patients.When the results were compared with those obtained by the direct sequencing protocol,the LNA-RT-PCR method showed the same results in all but one of 87 positive detected samples(98.9%specificity).CONCLUSION The newly developed LNA-RT-PCR method could identify two rt269 polymorphisms,rt269L and rt269I,in CHB patients with genotype C2 infections.This method could be effectively used for the understanding of disease progression in genotype C2 endemic areas.

A Novel Fusion Protein Possessing Both Antiviral and pHSA-binding Activities Composed of Hepatitis B Virus Pre-S2 Peptide and Human α2a-interferon

The human α-interferon(IFNα) is a group of proteins possessing activity to render cells resistant to viral infection. It is one of the most promising and well documented recombinant proteins used in biotherapy. A product of recombinant human α2a-interferon(IFN-α2a) first developed in our laboratory has been put into clinical trials upon the approval of the China National Committee for Drug Administration. Data show that

Hepatitis B virus pre-S/S variants in liver diseases

Chronic hepatitis B is a global health problem. The clinical outcomes of chronic hepatitis B infection include asymptomatic carrier state, chronic hepatitis(CH), liver cirrhosis(LC), and hepatocellular carcinoma(HCC). Because of the spontaneous error rate inherent to viral reverse transcriptase, the hepatitis B virus(HBV) genome evolves during the course of infection under the antiviral pressure of host immunity. The clinical significance of pre-S/S variants has become increasingly recognized in patients with chronic HBV infection. Pre-S/S variants are often identified in hepatitis B carriers with CH, LC, and HCC, which suggests that these naturally occurring pre-S/S variants may contribute to the development of progressive liver damage and hepatocarcinogenesis. This paper reviews the function of the pre-S/S region along with recent findings related to the role of pre-S/S variants in liver diseases. According to the mutation type, five pre-S/S variants have been identified: pre-S deletion, pre-S point mutation, pre-S1 splice variant, C-terminus S point mutation, and pre-S/S nonsense mutation. Their associations with HBV genotype and the possible pathogenesis of pre-S/S variants are discussed. Different pre-S/S variants cause liver diseases through different mechanisms. Most cause the intracellular retention of HBV envelope proteins and induction of endoplasmic reticulum stress, which results in liver diseases. Pre-S/S variants should be routinely determined in HBV carriers to help identify individuals who may be at a high risk of less favorable liver disease progression. Additional investigations are required to explore the molecular mechanisms of the pre-S/S variants involved in the pathogenesis of each stage of liver disease.

Different pre-S deletion patterns and their association with hepatitis B virus genotypes

AIM To investigate the associations of different types of pre-S deletions with hepatitis B virus(HBV) genotypes.METHODS The sequences of the pre-S region, basal core promoter(BCP) mutation, and precore(PC) mutation were examined through direct DNA sequencing or clonal analysis and sequencing in 273 HBV carriers, namely 55 asymptomatic carriers, 55 carriers with chronic hepatitis(CH), 55 with liver cirrhosis(LC), 53 with liver cirrhotic hepatocellular carcinoma(LC-HCC), and 55 with noncirrhotic HCC. A total of 126 HBV carriers(46.2%) harbored pre-S deletions. The DNA sequences of pre-S deletion mutants from 43 age-matched genotype B(HBV/B)-infected carriers and 43 agematched genotype C(HBV/C)-infected carriers were further examined, aligned, and compared.RESULTS No significant difference was observed in the mean age distribution(P = 0.464), male sex(P = 0.805), viral load(P = 0.635), or BCP mutation(P = 0.117) between the HBV/B and HBV/C groups. However, the rate of PC mutation was significantly higher in the HBV/B-infected carriers than in the HBV/C-infected carriers(P = 0.003). Both genotypes exhibited a high rate of deletion in the C-terminal half of the pre-S1 region and N-terminus of the pre-S2 region(86.0% and 79.1% in the HBV/B group; 69.8% and 72.1% in the HBV/C group, respectively). Epitope mapping showed that deletion in several epitope sites was frequent i n both genotypes, particularly p S1-BT and p S2-B2. Conversely, the rate of p S2-B1 deletion was significantly higher in the HBV/B group(72.1% vs 37.2%, P = 0.002), and the rate of pS 2-T deletion was significantly higher in the HBV/C group(48.8% vs 25.6%, P = 0.044). Functional mapping showed that the rate of deletion in three functional sites(the nucleocapsid binding site, start codon of M, and site for viral secretion) located in the N-terminus of the pre-S2 region was significantly higher in the HBV/B group(P < 0.05). One type of N-terminus pre-S1 deletion mutant with deletion of the start codon of the L protein was frequently observed in the HBV/C group(20.9% vs 9.3%, P = 0.228), particularly in the LC patients(42.9% vs 12.5%). Different patterns of pre-S deletions were also found between the HBV/B and HBV/C groups according to different clinical outcomes. In CH patients, deletion in the site for polymerized human serum albumin was more frequent in the HBV/B group(88.9% vs 36.4%, P = 0.028). In the LC-HCC patients, the rate of deletion in the pre-S2 region was significantly higher in the HBV/B group than in the HBV/C group(P < 0.05).CONCLUSION HBV/B- and HBV/C-infected carriers exhibit different patterns of pre-S deletion, which may be associated with the progression of liver diseases.

Novel approach to identifying the hepatitis B virus pre-S deletions associated with hepatocellular carcinoma

AIM: To develop a novel non-sequencing method for the detection of hepatitis B virus (HBV) pre-S deletion mutants in HBV carriers.

Serum soluble interleukin-2 receptor levels in patients with chronic hepatitis B virus infection and its relation with antiHBc

AIM： To investigate the relationship between serum soluble interleukin-2 receptor （sIL-2R） level and anti-HBc in patients with chronic hepatitis B virus （HBV） infection. METHODS： Sera from 100 patients with chronic HBV infection and 30 healthy controls were included in this study. The patients were divided into group A [HBsAg （＋）, HBeAg （＋） and anti-HBc （＋）, n = 50] and group B [HBsAg （＋）, HBeAg （＋） and anti-HBc （-）, n = 50]. sIL-2R levels were determined using ELISA. HBV DNA and alanine aminotransferase （ALT） were also detected. RESULTS： Serum sIL-2R levels were significantly higher in patients with chronic HBV infection than in healthy controls. Moreover, serum sIL-2R levels were significantly higher in patients with HBsAg （＋）, HBeAg （＋） and antiHBc （＋） （976.56±213.51×10^3 U/L） than in patients with HBsAg （＋）, HBeAg （＋） and anti-HBc （-） （393.41±189.54 ×10^3 U/L, P〈 0.01）. A significant relationship was found between serum sIL-2R and ALT levels （P〈 0.01） in patients with chronic HBV infection, but there was no correlation between sIL-2R and HBV DNA levels. The anti-HBc status was significantly related to the age of patients （P〈 0.01）. CONCLUSION： The high sIL-2R level is related to positive anti-HBc in chronic hepatitis B patients. Positive anti-HBc may be related to T-lymphocyte activation and negative anti-HBc may imply immune tolerance in these patients.

Efficacies of β-L-D4A against Hepatitis B virus in 2.2.15 cells

AIM： To investigate the antiviral effect of beta-L- enantiomer of 2;3＇-didehydro-2＇,3″-dideoxyadenosine （13-L-D4A） on 2.2.15 cells transfected with the hepatitis B virus （HBV） genome.METHODS： Lamivudine （3TC） as a positive control. Then, HBV DNA in treated 2.2.15 cells and the Hepatitis B surface antigen （HBsAg） in the culture supernatants were detected to determine the inhibitory effect of β-L- D4A. At the same time, 3-（4,5-dimethylthiazol-2-yl）-2,5- diphenyltetrazolium bromide （MTT） was used to detect the survival ratio of 2.2.15 cells.RESULTS： β-L-D4A has a dose-dependent inhibitory effect on HBV DNA replication; this effect was apparent when the concentration was above 1 mol/L. When β-L- D4A was at the highest concentration, 100 mol/L, the HBsAg inhibition ratio was above 50%. The Therapeutic index （TI） of β-L-D4A was above 2.1.CONCLUSION： β-L-D4A has a dose-dependent inhibitory effect on the replication of HBV DNA and the secretion of HBsAg at low toxicity,

Inhibition of hepatitis B virus production by Boehmeria nivea root extract in HepG2 2.2.15 cells

AIM: To explore the anti-hepatitis B virus (HBV) effects of Boehmeria nivea (B. nivea) root extract (BNE) by using the HepG2 2.2.15 cell model system. METHODS: Hepatitis B surface antigen (HBsAg), hepatitis B virus e antigen (HBeAg), and HBV DNA were measured by using ELISA and real-time PCR, respectively. Viral DNA replication and RNA expression were determined by using Southern and Northern blot, respectively. RESULTS: In HepG2 2.2.15 cells, HBeAg (60%, P < 0.01) and particle-associated HBV DNA (> 99%, P < 0.01) secretion into supernatant were significantly inhibited by BNE at a dose of 100 mg/L, whereas the HBsAg was not inhibited. With different doses of BNE, the reduced HBeAg was correlated with the inhibition of HBV DNA. The anti-HBV effect of BNE was not caused by its cytotoxicity to cells or inhibition of viral DNA replication and RNA expression. CONCLUSION: BNE could effectively reduce the HBV production and its anti-HBV machinery might differ from the nucleoside analogues.

Hepatitis B virus/hepatitis D virus epidemiology: Changes over time and possible future influence of the SARS-CoV-2 pandemic

Hepatitis D virus(HDV)is a defective liver-tropic virus that needs the helper function of hepatitis B virus(HBV)to infect humans and replicate.HDV is transmitted sexually or by a parenteral route,in co-infection with HBV or by super-infection in HBV chronic carriers.HDV infection causes acute hepatitis that may progress to a fulminant form(7%-14%by super-infection and 2%-3%by HBV/HDV co-infection)or to chronic hepatitis(90%by HDV super-infection and 2%-5%by HBV/HDV co-infection),frequently and rapidly progressing to cirrhosis or hepatocellular carcinoma(HCC).Peg-interferon alfa the only recommended therapy,clears HDV in only 10%-20%of cases and,consequently,new treatment strategies are being explored.HDV endemicity progressively decreased over the 50 years from the identification of the virus,due to improved population lifestyles and economic levels,to the use of HBV nuclei(t)side analogues to suppress HBV replication and to the application of universal HBV vaccination programs.Further changes are expected during the severe acute respiratory syndrome coronavirus-2 pandemic,unfortunately towards increased endemicity due to the focus of healthcare towards coronavirus disease 2019 and the consequently lower possibility of screening and access to treatments,lower care for patients with severe liver diseases and a reduced impulse to the HBV vaccination policy.

Interaction between hepatitis B virus and SARS-CoV-2 infections

Coronavirus disease 2019(COVID-19)has become a global pandemic and garnered international attention.The causative pathogen of COVID-19 is severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel,highly contagious coronavirus.Numerous studies have reported that liver injury is quite common in patients with COVID-19.Hepatitis B has a worldwide distribution as well as in China.At present,hepatitis B virus(HBV)remains a leading cause of cirrhosis,liver failure,and hepatocellular carcinoma.Because both viruses challenge liver physiology,it raises questions as to how coinfection with HBV and SARS-CoV-2 affect disease progression and mortality.Is there an increased risk of COVID-19 in patients with HBV infection?In this review,we summarize the current reports of SARS-CoV-2 and HBV coinfection and elaborate the interaction of the two diseases.The emphasis was placed on evaluating the impact of HBV infection on disease severity and clinical outcomes in patients with COVID-19 and discussing the potential mechanism behind this effect.

Inhibitory effect of miR-125b on hepatitis C virus core protein-induced TLR2/My D88 signaling in THP-1 cells

AIM: To investigate the role of mi R-125 b in regulating monocyte immune responses induced by hepatitis C virus(HCV) core protein.METHODS: Monocytic THP-1 cells were treated with various concentrations of recombinant HCV core protein, and cytokines and mi R-125 b expression in these cells were analyzed. The requirement of Tolllike receptor 2(TLR2) or My D88 gene for HCV core protein-induced immune responses was determined by the transfection of THP-1 cells with gene knockdown vectors expressing either TLR2 si RNA or My D88 si RNA. The effect of mi R-125 b overexpression on TLR2/My D88 signaling was examined by transfecting THP-1 cells with mi R-125 b mimic RNA oligos.RESULTS: In response to HCV core protein stimulation, cytokine production was up-regulated and mi R-125 b expression was down-regulated in THP-1 cells. The modulatory effect of HCV core protein on cellular events was dose-dependent and required functional TLR2 or My D88 gene. Forced mi R-125 b expression abolished the HCV core protein-induced enhancement of tumor necrosis factor-α, interleukin(IL)-6, and IL-10 expression by 66%, 54%, and 66%, respectively(P < 0.001), by inhibiting My D88-mediated signaling, including phosphorylation of NF-k Bp65, ERK, and P38.CONCLUSION: The inverse correlation between mi R-125 b and cytokine expression after HCV core challenge suggests that mi R-125 b may negatively regulate HCVinduced immune responses by targeting TLR2/My D88 signaling in monocytes.

HBsAg stimulates NKG2D receptor expression on natural killer cellsand inhibits hepatitis C virus replication

Background： Higher hepatitis B surface antigen （HBsAg） facilitates hepatitis C virus （HCV） clearance inpatients with hepatitis B virus （HBV）/HCV co-infection. We investigated the effect of exogenous HBsAgon the inhibition of HCV replication mediated by natural killer （NK） cells.

Adenovirus-expressed preS2 antibody inhibits hepatitis B virus infection and hepatic carcinogenesis

AIM:To investigate the inhibitory effect of hepatitis B virus (HBV) preS2 antibody (preS2Ab) against HBV in-fection and HBV-associated hepatic carcinogenesis.METHODS:An adenoviral vector carrying the full-length light and heavy chains of the HBV preS2Ab gene,Ad315-preS2Ab,was constructed.Enzyme linked immunosorbent assay (ELISA) and Western blotting analyses were used to determine the preS2Ab expres-sion levels in vitro.Immunofluorescent techniques were used to examine the binding affinity between the expressed HBV preS2Ab and HBV-positive liver cells.ELISAs were also used to determine hepatitis B surface antigen (HBsAg) levels to assess the inhibitory effect of the preS2Ab against HBV infection in L02 cells.The inhibitory effect of preS2Ab against hepatic carcinogen-esis was studied with diethylnitrosamine (DEN)-induced hepatocellular carcinomas (HCCs) in HBV transgenic mice.RESULTS:The expression of HBV preS2Ab increased with increases in the multiplicity of infection (MOI) of Ad315-preS2Ab in L02 cells,with 350.87 ± 17.37 μg/L of preS2Ab when the MOI was 100 plaque forming units (pfu)/cell.The expressed preS2Abs could recog-nize liver cells from HBV transgenic mice.ELISA results showed that L02 cells expressing preS2Ab produced less HBsAg after treatment with the serum of HBV pa-tients than parental L02 cells expressing no preS2Ab.HBV transgenic mice treated with Ad315-preS2Ab had fewer and smaller cancerous nodes after induction with DEN than mice treated with a blank Ad315 vec-tor or untreated mice.Additionally,the administration of Ad315-preS2Ab could alleviate hepatic cirrhosis and decrease the serum levels of alanine transaminase and aspartate transaminase.CONCLUSION:Adenovirus-mediated HBV preS2Ab expression could inhibit HBV infection in L02 cells,and then inhibit DEN-induced hepatocellular carcinogenesis and protect hepatic function in HBV transgenic mice.

Hepatitis B virus X protein regulates the mEZH2 promoter via the E2F1-binding site in AML12 cells

Histone lysine methyltransferase EZH2 has been reported to be frequently overexpressed in hepatocellular carcinoma(HCC) tissues and associated with hepatocarcinogenesis.However,the exact mechanism of EZH2 up-regulation in HCC has not been determined.In this study,we used murine hepatocyte AML12 cells to investigate the role of hepatitis B virus X protein(HBx) in regulating the expression of mEZH2.Western blot analysis demonstrated that the expression level of mEZH2 protein in AML12 cells was up-regulated by HBx in a dose-dependent manner.To further investigate the mechanism of mEZH2 overexpression,the 2500 bp regulatory sequence upstream from the first exon of the mEZH2 gene was amplified from AML12 genomic DNA and constructed into a luciferase reporter plasmid.The luciferase activity of the mEZH2 promoter significantly increased in AML12 cells co-transfected with HBx plasmid,and deleting the-486/-214 promoter region decreased HBx-induced mEZH2 promoter activation by nearly 50%.The-486/-214 region was then analyzed in the TRANSFAC 6.0 database and a typical E2F1-binding site was found.Mutation of this E2F1-binding site or knockdown of E2F1 expression by RNAi led to a dramatic decrease in HBx-induced activation of the mEZH2 promoter and mEZH2 overexpression in AML12 cells.These results provide evidence that HBx up-regulates mEZH2 expression by transactivating the mEZH2 promoter through E2F1 transcription factor,thereby providing new epigenetic evidence for the carcinogenic effect of HBx.

Generation of Hepatitis B virus PreS2-S antigen in Hansenula polymorpha

Despite the long availability of a traditional prophylactic vaccine containing the HBV surface antigen(HBsA g) and aluminum adjuvant, nearly 10% of the population remains unable to generate an effective immune response. Previous studies have indicated that hepatitis B virus(HBV) PreS 2-S is abundant in T/B cell epitopes, which induces a stronger immune response than HBsA g, particularly in terms of cytotoxic T lymphocyte(CTL) reaction. In the current study, the HBV PreS 2-S gene encoding an extra26 amino acids(PreS 2 C-terminus) located at the N-terminus of HBsA g was cloned into the pV CH1300 expression vector. Pre S2-S expressed in the methylotrophic yeast, Hansenula polymorpha, was produced at a yield of up to 250 mg/L. Subsequent purification steps involved hydrophobic adsorption to colloidal silica, ion-exchange chromatography and density ultracentrifugation. The final product was obtained with a total yield of ~15% and purity of ~99%. In keeping with previous studies, ~22 nm viruslike particles were detected using electron microscopy. The generated PreS 2-S antigen will be further studied for efficacy and safty in animals.

A Comparative Study on Serum PreS2 and Polymerized Human Serum Albumin Binding Activity in Patients with Chronic Hepatitis B Virus Infection

Antiserum against PreS2 peptide was raised with a synthetic polypeptide from the rabbits.The anti-preS2 antibody and polymerized human serum albumin were used as reagents in aradioimmunoassay to detect preS2 and polymerized human serum albumin bindingactivity respectively. Both were absent in patients with hepatitis A or HBsAg negative chronic liver di-seases. In biopsy - proven patients with chronic active hepatitis (CAH)B, prevalences of bothmarkers were significantly higher at exacerbation that at remission stage of the disease, and so werein CAH than in chronic asymptomatic HBV carrier (AsC) with normal histology. Besides, the pre-valences were significantly higher in HBeAg positive group than in anti-HBe positive group.However, the polymerized human serum albumin binding activity and the preS2 were undoubtedlynot the same, as the prevalence of the latter was only 56.7% of the former.