Targeting hepatitis B virus antigens to dendritic cells by heat shock protein to improve DNA vaccine potency

AIM： To investigate a novel DNA vaccination based upon expression of the HBV e antigen fused to a heat shock protein （HSP） as a strategy to enhance DNA vaccine potency.METHODS： A pCMV-HBeAg-HSP DNA vaccine and a control DNA vaccine were generated. Mice were immunized with these different construct. Immune responses were measured 2 wk after a second immunization by a T cell response assay, CTL cytotoxicity assay, and an antibody assay in C57BL/6 and BALB/c mice. CT26-HBeAg tumor cell challenge test in vivo was Performed in BALB/c mice to monitor anti-tumor immune responses.RESULTS： In the mice immunized with pCMV-HBe-HSP DNA, superior CTL activity to target HBV-positive target cells was observed in comparison with mice immunized with pCMV-HBeAg （44% ± 5% vs 30% ± 6% in E： T 〉 50：1, P 〈 0,05）, ELISPOT assays showed a stronger T-cell response from mice immunized with pCMV-HBe- HSP than that from pCMV-HBeAg immunized animals when stimulated either with MHC class I or class Ⅱ epitopes derived from HBeAg （74% ± 9% vs 31% ± 6%, P 〈 0.01）. ELISA assays revealed an enhanced HBeAg antibody response from mice immunized with pCMV- HBe-HSP than from those immunized with pCMV-HBeAg. The lowest tumor incidence and the slowest tumor growth were observed in mice immunized with pCMV- HBe-HSP when challenged with CT26-HBeAg.CONCLUSION： The results of this study demonstrate a broad enhancement of antigen-specific CD4^＋ helper,CD8^＋ cytotoxic T-cell, and B-cell responses by a novel DNA vaccination strategy. They also proved a stronger antigen-specific immune memory, which may be superior to currently described HBV DNA vaccination strategies for the treatment of chronic HBV infection.

Enhancement of CTLs induced by DCs loaded with ubiquitinated hepatitis B virus core antigen

AIM： To investigate whether hepatitis B virus （HBV） could induce a hepatitis B virus core antigen （HBcAg）specific cytotoxic T lymphocyte （CTL） response in vitro by dendritic cells （DCs） transduced with lentiviral vector-encoding ubiquitinated hepatitis B virus core antigen （LV-Ub-HBcAg）.METHODS： Recombinant LV-Ub-HBcAg were transfected into highly susceptible 293 T cells to obtain high virus titres, Bone marrow-derived DCs isolated from BALB/c mice were cultured with recombinant granulocyte-macrophage colony-stimulating factor and recombinant interleukin （IL）-4. LV-Ub-HBcAg, lentiviral vector-encoding hepatitis B virus core antigen （LV-HBcAg）, lentiviral vector （LV） or lipopolysaccharide were added to induce DC maturation, and the DC phenotypes were analyzed by flow cytometry. The level of IL-12 in the supernatant was detected by enzyme-linked immunosorbent assay （ELISA）. T lymphocytes were proliferated using Cell Counting Kit-8. DCs were cultured and induced to mature using different LVs, and co-cultured with allogeneic T cells to detect the secretion levels of IL-2, IL-4, IL-10and interferon-γ in the supernatants of T cells by ELISA. Intracellular cytokines of proliferative T cells were analyzed by flow cytometry, and specific CTL activity was measured by a lactate dehydrogenase release assay.RESULTS： LV-Ub-HBcAg-induced DCs secreted more IL-12 and upregulated the expression of CD80, CD86 and major histocompatibility class ]I, DCs sensitised by different LVs effectively promoted cytokine secretion; the levels of IL-2 and interferon-y induced by LV-Ub- HBcAg were higher than those induced by LV-HBcAg, Compared with LV-HBcAg-transduced DCs, LV-Ub- HBcAg-transduced DCs more efficiently stimulated the proliferation of T lymphocytes and generated HBcAgspecific cytotoxic T lymphocytes.CONCLUSION： LV-Ub-HBcAg effectively induced DC maturation. The mature DCs efficiently induced T cell polarisation to Thl and generated HBcAg-specific CTLs.

Screening and evaluation of human single-chain fragment variable antibody against hepatitis B virus surface antigen

BACKGROUND: Phage display technology has become a vital tool in studies aimed at identifying molecules binding to a specific target. It enables the rapid generation and selection of high affinity, fully human antibody product candidates to essentially any disease target appropriate for antibody therapy. In this study, we prepared the recombinant single-chain fragment variable ( ScFv) antibody to hepatitis B virus surface antigen (HBsAg) by the phage display technology for obtaining a virus-targeting mediator. METHODS: mRNA was isolated from B-lymphocytes from a healthy volunteer and converted into cDNA. The fragment variables of heavy and light chain were amplified separately and assembled into ScFv DNA with a specially constructed DNA linker by polymerase chain reaction. The ScFv DNA was ligated into the phagmid vector pCANT-AB5E and the ligated sample was transformed into competent E. coli TG1. The transformed cells were infected with M13K07 helper phage to form a human recombinant phage antibody library. The volume and recombinant rate of the library were evaluated by bacterial colony count and restriction analysis. After two rounds of panning with HBsAg. the phage clones displaying ScFv of the antibody were selected by enzyme-linked immunosorbant assay ( ELISA) from the enriched phage clones. The antigen binding affinity of the positive clone was detected by competition ELISA. HB2151 E. coli was transfected with the positive phage clone demonstrated by competition ELISA for production of a soluble form of the anti-HBsAg ScFv. ELISA assay was used to detect the antigen binding affinity of the soluble anti-HBsAg ScFv. Finally, the relative molecular mass of soluble anti-HBsAg ScFv was measured by SDS-PAGE. RESULTS: The variable heavy ( VH ) and variable light (VL) and ScFv DNAs were about 340bp, 320bp and 750bp, respectively. The volume of the library was up to 2 × 106 and 8 of 10 random clones were recombinants. Two phage clones could strongly compete with the original HBsAb for binding to HBsAg. Within 2 strong positive phage clones, the soluble anti-HBsAg ScFv from one clone was found to have the binding activity with HBsAg. SDS-PAGE showed that the relative molecular weight of soluble anti-HBsAg ScFv was 32 kDa. CONCLUSION: The anti-HBsAg ScFv successfully produced by phage antibody technology may be useful for broadening the scope of application of the antibody.

Significance of hepatitis B virus surface antigen, hepatitis C virus expression in hepatocellular carcinoma and pericarcinomatous tissues

AIM： To investigate the correlation between hepatitis B virus surface antigen （HBsAg）, hepatitis C virus （HCV） expression in hepatocellular carcinoma （HCC）, the HAI score of the noncancerous region of the liver and the serum Alpha fetoprotein （AFP） level. METHODS： The patterns of HBsAg and HCV in 100 cases of HCC and their surrounding liver tissues were studied on paraffin-embedded sections with immunohistochemistry, the histological status was determined by one pathologist and one surgeon simultaneously using the hepatitis activity index （HAIl score, and AFP was detected by radioimmunity. The study included 100 consecutive patients who underwent curative resection for HCC. Based on HBsAg and HCV expression, the patients were classified into 4 groups： patients positive for HBsAg （HBsAg group）, patients positive for HCV （HCV group）, patients negative for both HCV and HBsAg （NBNC group） and patients positive for both HBsAg and HCV （BC group）. RESULTS： The BC group had significantly higher HAI scores than the other three groups. （BC 〉 HCV 〉 HBsAg 〉 NBNC）. HBV and HCV virus infection was positively correlated with HAI （rs = 0.39, P = 0.00011. The positive rate of AFP （85.7%） and the value of AFP （541.2 ng/mL） in the group with HBV and HCV co-infection were the highest among the four groups. The positive rate （53.3%） of AFP and the value of AFP （ 53.3 ng/mL） in the group with none-infection of HBV and HCV were the lowest. HBV and HCV virus infection was positively correlated with AFP（rs = 0.38, P = 0.0001）. CONCLUSION： The AFP increase in patients with liver cancer was positively correlated with the infection of HBV and HCV. The-serum AFP elevation by the infection of HBV and HCV is one of mechanisms which lead to hepatocarcinogenesis, and the antivirus intervening treatment of hepatitis is significant for the prognosis of liver cancer. From our Spearman＇s rank correlation analysis, we can conclude that the severity of virally induced inflammation is correlated with HBsAg and HCV expression in HCC tissues and noncancerous tissues. Prior co-infection of HBV in HCV patients may be an adverse risk factor for intrahepatic inflammation.

Hepatitis B virus markers in hepatitis B surface antigen negative patients with pancreatic cancer:Two case reports

BACKGROUND Hepatitis B virus(HBV)is a known carcinogen that may be involved in pancreatic cancer development.Detection of HBV biomarkers[especially expression of HBV regulatory X protein(HBx)]within the tumor tissue may provide direct support for this.However,there is still a lack of such reports,particularly in non-endemic regions for HBV infection.Here we present two cases of patients with pancreatic ductal adenocarcinoma,without a history of viral hepatitis,in whom the markers of HBV infection were detected in blood and in the resected pancreatic tissue.CASE SUMMARY The results of examination of two patients with pancreatic cancer,who gave informed consent for participation and publication,were the source for this study.Besides standards of care,special examination to reveal occult HBV infection was performed.This included blood tests for HBsAg,anti-HBc,anti-HBs,HBV DNA,and pancreatic tissue examinations with polymerase chain reaction for HBV DNA,pregenomic HBV RNA(pgRNA HBV),and covalently closed circular DNA HBV(cccDNA)and immunohistochemistry staining for HBxAg and Ki-67.Both subjects were operated on due to pancreatic ductal adenocarcinoma and serum HBsAg was not detected.However,in both of them anti-HBc antibodies were detected in blood,although HBV DNA was not found.Examination of the resected pancreatic tissue gave positive results for HBV DNA,expression of HBx,and active cellular proliferation by Ki-67 index in both cases.However,HBV pgRNA and cccDNA were detected only in case 1.CONCLUSION These cases may reflect potential involvement of HBV infection in the development of pancreatic cancer.

EXPRESSION OF INSULIN-LIKE GROWTH FACTOR Ⅱ(IGF-Ⅱ)IN HUMAN HEPATOCELLULAR CARCINOMA AND LIVER CIRRHOSIS:ITS RELATIONSHIP WITH HEPATITIS B VIRUS X PROTEIN EXPRESSION

Sixty cases of hepatocellular carcinoma (HCC) and 47 cases of liver cirrhosis (LC) were examined with immunocytochemistry method using antibodies against IGF-II and HBxAg on formalin-fixed, paraffin-embedded tissue sections. 32 HCC and 37 LC were found to be positive to HBxAg, in which the positive rates of IGF-II were 100% (32/32) and 94.6% (35/37) respectively. 28 HCC and 10 LC were found to be HBxAg negative, IGF-II was positive in 23 HCC (83.1%) and 6 LC (60%). The positive expression rates of IGF-II in HBxAg positive tissues were significantly higher than those in HBxAg negative tissues (P<0.05). There were three types of distribution of IGF-II expression in HCC and LC: (1) perinucleus; (2) diffuse in cytoplasm; (3) inside nucleus. IGF-II was highly expressed in most of hyperplastic and neoplastic nodules hepatocytes and some of regeneration nodules. Small polygonal liver cells (SPLCs) were found in the liver tissues surrounding the tumor and cirrhosis and they were positive to both IGF-II and HBxAg. The positive rates of IGF-II in SPLC were 86.4% (38/44) in the HBxAg-positive tissues and 40.5%, (15/37) in the HBxAg-negative tissues. The above findings suggest that IGF-II plays an important role in abnormal proliferation of HCC and SPLC. The relation between IGF-II andHBxAg and the nature of SPLCs are also discussed.

Occult hepatitis B virus and hepatocellular carcinoma

Occult hepatitis B virus(HBV)infection(OBI)is a challenging pathobiological and clinical issue that has been widely debated for several decades.By definition,OBI is characterized by the persistence of HBV DNA in the liver tissue(and in some cases also in the serum)in the absence of circulating HBV surface antigen(HBsAg).Many epidemiological and molecular studies have indicated that OBI is an important risk factor for hepatocellular carcinoma(HCC)development.OBI may exert direct pro-oncogenic effects through the activation of the same oncogenic mechanisms that are activated in the course of an HBsAg-positive infection.Indeed,in OBI as in HBV-positive infection,HBV DNA can persist in the hepatocytes both integrated into the host genome as well as free episome,and may maintain the capacity to produce proteins-mainly X protein and truncated preS-S protein-provided with potential transforming properties.Furthermore,OBI may indirectly favor HCC development.It has been shown that the persistence of very low viral replicative activity during OBI may induce mild liver necro-inflammation continuing for life,and substantial clinical evidence indicates that OBI canaccelerate the progression of liver disease towards cirrhosis that is considered the most important risk factor for HCC development.

Novel DNA vaccine based on hepatitis B virus core gene induces specific immune responses in Balb/c mice

AIM： To investigate the immunogenidty of a novel DNA vacoine, pSW3891/HBc, based on HBV core gene in Balb/c mice. METHODS： A novel DNA vaccine, pSW3891/HBc, encoding HBV core gene was constructed using a vector plasmid pSW3891. Balb/c mice were immunized with either pSW3891/HBc or empty vector DNA via gene gun. IgG anti-HBc responses in mouse sera were demonstrated by ELISA. Specific cytotoxicity of cytotoxic T lymphocytes （CTLs） of mice was quantitatively measured by lactate dehydrogenase release assay. RESULTS： HBcAg was expressed effectively in 293T cell line transiently transfected with pSW3891/HBc. Strong IgG anti-HBc responses were elicited in mice immunized with pSW3891/HBc. The end-point titers of anti-HBc reached the highest 1：97 200, 4 wk after the third immunization. The specific CTL killing with the highest specific lysis reached 73.25% at effector：target ratio of 20：1 in mice that received pSW3891/HBc DNA vaccine. CONCLUSION： pSW3891/HBc vaccination elicits specific anti-HBc response and induces HBc-specific CTL response in immunized Balb/c mice.

Review on hepatitis B virus precore/core promoter mutations and their correlation with genotypes and liver disease severity

Of 350 million people worldwide are chronically infected with hepatitis B virus(HBV)and are at risk of developing cirrhosis and hepatocellular carcinoma(HCC)later in life.HBV is the most diverse DNA virus,and its genome is composed of four open reading frames:Presurface antigen/surface antigen gene(preS/S),precore/core gene(preC/C),polymerase gene(P),and theχgene(χ).HBV produces quasispecies naturally or in response to antiviral agents because of the absence of proofreading activity amid reverse transcription and a high replication rate.The virus has 10 genotypes(A to J)with different geographical distributions.There are various HBV mutations in the HBV genome,including preC/C mutations,preS/S mutations,P gene mutations,andχgene mutations.The core promoter region plays a vital part in the replication,morphogenesis and pathogenesis of the virus.The precore region also plays a crucial role in viral replication.Both core promoter and precore mutations rescue the virus from host immune surveillance and result in the formation of mutated strains that may have altered pathogenicity.preC/C mutations are associated with liver disease progression.Precore mutations stop hepatitis B e antigen(HBeAg)production and basal core promoter mutations downregulate HBeAg production.Mutations in the basal core promoter are also associated with increased HBV replication and an increased incidence of advanced liver diseases such as cirrhosis and HCC.The emergence of antiviral-resistant mutations is the main reason for treatment failure.This review focuses mainly on preC/C promoter mutations and their correlation with genotypes and liver disease severity.Thorough perception and knowledge of HBV genetic variety and mutants could be vital to discover techniques for the prognosis and control of HBV infection.

Applicability and efficacy of a model for prevention of perinatal transmission of hepatitis B virus infection:Single center study in Egypt

AIM: To identify possible maternal risk factors for hepatitis B virus (HBV) acquisition and assess the efficacy of immunoprophylaxis given to infants born to hepatitis B virus surface antigen (HBsAg) positive mothers.

Basic Study Hepatitis B virus detected in paper currencies in a densely populated city of India: A plausible source of horizontal transmission?

BACKGROUND The recent rise in the incidence of hepatitis B virus(HBV)infections in a densely populated city of eastern India(“mixing vessel”of people of varied socioeconomic and immune status)prompted this study.Applying saliva on fingers for enumerating bank notes is a common practice in the Indian subcontinent.Paper notes may be a potential source of“horizontal”transmission of this virus,especially if there are cuts/bruises on the oral mucous membrane or skin.AIM To investigate whether paper currencies could be a plausible mode of horizontal transmission of HBV infection.METHODS Polymerase chain reactions(PCR)followed by nucleotide sequencing was done for the detection of HBV.Hepatitis B virus surface antigen enzyme-linked immunosorbent assay(HBsAg ELISA)was performed on all HBV deoxyribonucleic acid-positive samples to check the detectability of the virus.Atomic force microscopy(AFM)was carried out for visual confirmation of HBV particles in ultracentrifuged/immunoprecipitated samples from currency paper washings.RESULTS HBV-specific PCRs on pellets obtained after ultracentrifugation/immunoprecipitation of the currency paper washings detected potentially intact/viable HBV(genotype D2)in 7.14%of samples(n=70).AFM gave the visual confirmation of HBV particles in ultracentrifuged/immunoprecipitated samples from currency paper washings.However,HBV isolates from the currency notes could not be detected by HBsAg ELISA.CONCLUSION It is a common practice in the Indian subcontinent to count paper currencies by applying saliva on fingertips.Paper notes may be a potential source of“horizontal”transmission of this virus,especially if there are cuts/bruises on the oral mucous membrane or skin,but it was practically not possible to demonstrate experimentally such transmission.Detection of potentially intact/viable and“occult”HBV from currency poses potential risk of silent transmission of this virus among the general population.

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.

Cloning and characterization of a novel hepatitis B virus core binding protein C12

AIM： To elucidate the biological function of HBV core antigen （HBcAg） on pathogenesis of hepatitis B, a novel gene C12 coding for protein with unknown function interacting with HBcAg in hepatocytes was identified and characterized. METHODS： HBcAg bait plasmid pGBKT7-HBcAg was constructed and transformed into yeast AH109, then the transformed yeast was mated with yeast Y187 containing liver complementary DNA （cDNA） library plasmid in 2xYPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium （SD/-Trp-Leu-His-Ade） and synthetic dropout nutrient medium （SD/-Trp-Leu-His-Ade） containing X-α-gal for screening twice. After extracting and sequencing of plasmid from blue colonies, we isolated a cDNA clone encoding a novel protein designated as C12 that directly interacted with HBcAg. The interaction between HBcAg and C12 was verified again by re-mating. pEGFP-N1-C12 fluorescent protein fusion gene was transfected in 293 and L02 cell, and observed by fluorescent microscope. M-FI reduction assay was used to study the action of C12 protein effect on metabolism of mammal cell. Yeast two-hybrid and cDNA microarray were performed to search binding protein and differential expression genes regulated by C12 protein. RESULTS： C12 gene was screened and identified by yeast two-hybrid system 3. The interaction between HBcAg and the novel protein coded by the new gene C12 was further confirmed by re-mating. After 48 h, fluorescence of fusion protein could be observed steadily in the 293 and L02 cell plasma. Under MTT assay, we found that the expression of C12 did not influence the growth of liver cells. Seventeen differential expression genes in HepG2 cells transfected with C12 protein expression plasmid by cDNA microarray, of which 16 genes were upregulated and 1 gene was downregulated by C12 protein. Twenty-one colonies containing 16 different genes coding for C12 protein binding proteins were isolated by yeast two-hybrid, there were 2 new genes with unknown function. CONCLUSION： The novel protein C12 is located in cell plasma, and its overexpression has no significant effect on the metabolism of liver cell. It interacts with many proteins in hepatocytes and may be involved in many processes of gene expression. 2005 The W.IG Press and Elsevier Inc. All rights reserved

Recognition of HBV antigens and HBV DNA by dendritic cells

BACKGROUND: Hepatitis B virus (HBV) is a hepatotropic, noncytopathic, DNA virus which can cause acute and chronic infection. Viral persistence is associated with a weak or absent specific immune responses to HBV, particularly the cellular immune response. Dendritic cells (DCs) are professional antigen-presenting cells with a unique T cell stimulatory aptitude that play a crucial role in the instruction of adaptive immune responses upon infection. An impaired function of DCs was suggested by recent studies to account for the T and B cell hyporesponsiveness in chronic HBV infection. This review summarizes recent insights into the recognition of HBV antigens by DCs. DATA SOURCES: Studies were identified by searching MEDLINE and/or PubMed for articles using the key words 'hepatitis B virus (HBV)', 'dendritic cells', 'C-type lectins', 'mannose receptor', 'toll-like receptor', and 'dendritic cell-specific intercellular-adhesion-molecule-3 grabbing nonintegrin (DC-SIGN)' up to December 2009. Additional papers were identified by a manual search of the references from the key articles. RESULTS: DCs play an important role in the progress of hepatitis B, especially in the recognition of HBV. There are three main ways of recognition of HBV antigens by DCs. First, HBV DNA can be recognized by DCs through toll-like receptor 9 (TLR9) which activates the NF-kappa B signal pathway and p38 MAPK to up-regulate the expression of interferon (IFN) regulatory factor 7 (IRF-7) in a manner independent of type I IFN signaling, resulting in secretion of type I IFN and inflammatory cytokines, and induction of DC maturation and the adaptive immune response. Second, HBc/HBeAg cannot be recognized by DCs, but DNA or ssRNA encapsulated within HBcAg can be internalized by DCs through TLRs. Third, HBsAg can be internalized by DCs through the mannose receptor, which lacks the ability to induce DC maturation without the assistance of DC-SIGN. Meanwhile, there is some cross-talk among the three mechanisms, which induces an effective anti-viral response or HBV persistence. CONCLUSIONS: On the basis of these recognition processes, methods have been used to enhance the efficacy of DC-based vaccine against HBV and have been useful in the clinical application of HBV vaccine therapy. But the interactions between HBV antigens/HBV DNA and DCs are not clear, and cross-talk between TLRs and various ligands makes HBV antigen recognition by DCs more complicated. More efforts should be made to define the mechanisms and develop effective vaccines and therapies. (Hepatobiliary Pancreat Dis Int 2010; 9:584-592)

Mutations in surface and polymerase gene of chronic hepatitis B patients with coexisting HBsAg and anti-HBs

AIM： To investigate the clinical significance and presence of mutations in the surface （S） and overlapping polymerase gene of hepatitis B patients with coexisting HBsAg and anti-HBs. METHODS： Twenty-three patients with chronic hepatitis B were studied. Of the 23 patients, i i were both positive for hepatitis B virus （HBV） surface antigen （HBsAg） and antibody to HBV surface antigen （anti-HBs）, 12 were negative for anti-HBs while positive for HBsAg. DNA was extracted from 200 μL serum of the patients. Nucleotide of the surface and overlapping polymerase gene from HBV-infected patients was amplified by PCR, and the PCR products were sequenced. RESULTS： Forty-one mutations were found within the surface gene protein of HBV in 15 patients （10 with coexisting HBsAg and anti-HBs）. Six （14.6%） out of 41 mutations were located at ＂α＂ determinant region in 5 patients （4 positive for HBsAg and anti-HBs）. Eleven mutations （26.8%） occurred in the downstream or upstream of ＂α＂ determinant region. Lamivudine （LMV）- selected mutations were found in three patients who developed anti-HBs, which occurred in amino acid positions （196, 198, 199） of the surface protein and in YMDD motif （M204I/V） of the polymerase protein simultaneously. Presence of these mutations did not relate to changes in ALT and HBV DNA levels.CONCLUSION： Besides mutations in the ＂α＂ determinant region, mutations at downstream or upstream of the ＂α＂ determinant region may contribute to the development of anti-HBs. These mutations do not block the replicating competency of HBV in the presence of high titer of anti-HBs.

Nationwide retrospective study of hepatitis B virological response and liver stiffness improvement in 465 patients on nucleos(t)ide analogue

BACKGROUND Hepatitis B virus(HBV)nucleos(t)ide analog(NA)therapy reduces liver disease but requires prolonged therapy to achieve hepatitis B surface antigen(HBsAg)loss.There is limited North American real-world data using non-invasive tools for fibrosis assessment and few have compared 1st generation NA or lamivudine(LAM)to tenofovir disoproxil fumarate(TDF).AIM To assess impact of NA on virological response and fibrosis regression using liver stiffness measurement(LSM)(i.e.,FibroScan®).METHODS Retrospective,observational cohort study from the Canadian HBV Network.Data collected included demographics,NA,HBV DNA,alanine aminotransferase(ALT),and LSM.Patients were HBV monoinfected patients,treatment naïve,and received 1 NA with minimum 1 year follow-up.RESULTS In 465(median 49 years,37%female,35%hepatitis B e antigen+at baseline,84%Asian,6%White,and 9%Black).Percentage of 64(n=299)received TDF and 166 were LAM-treated with similar median duration of 3.9 and 3.7 years,respectively.The mean baseline LSM was 11.2 kPa(TDF)vs 8.3 kPa(LAM)(P=0.003).At 5-year follow-up,the mean LSM was 7.0 kPa in TDF vs 6.7 kPa in LAM(P=0.83).There was a significant difference in fibrosis regression between groups(i.e.,mean-4.2 kPa change in TDF and-1.6 kPa in LAM,P<0.05).The last available data on treatment showed that all had normal ALT,but more TDF patients were virologically suppressed(<10 IU/mL)(n=170/190,89%)vs LAM-treated(n=35/58,60%)(P<0.05).None cleared HBsAg.CONCLUSION In this real-world North American study,approximately 5 years of NA achieves liver fibrosis regression rarely leads to HBsAg loss.

Risks of Viral Hepatitis B Transmission in Mother-to-Infant of Pregnant Women Carriers of Chronic Viral Hepatitis B in Cote d’Ivoire

The aim of this study was to identify the risk factors of mother-to-child transmission of HBV in positive Ag Hbs pregnant women in Cote d’Ivoire. Methods: This was a transversal prospective study that took place over a period of 7 months (from February 2016 to August 2016) in 2 university hospital and 2 private clinics. We consecutively recruited 91 pregnant women who were positive for HBs Ag in prenatal consultations. For each pregnant woman record included in the study, we provided Socio-demographic (Age, marital status, education level, social rank, gravidity, parity) and biological data (HBs Ag, Anti-HBc Total Ac, Hbe Ag, Ac anti-Hbe Ac, DNA-VHB, Ac anti-HCV Ac, retroviral serology, transaminases). All of these data were collected using a survey sheet developed for the study. Results: The age of our pregnant women HBs positive ranged from 18 years to 44 years with a mean age of 30.10 years. The age group from 20 to 39 years was the most represented with a frequency of 92.31%. Almost of all positive HBs Ag pregnant women was HBe Ag negative, only 3.3% was HBe Ag positive. The viral load above 2000 IU/ml was found in 21 (23.03%) patients. There were 4 co-infected patients, which 3 HBV-HIV and 1 HBV-HCV. Only 19 (20.88%) pregnant HBs Ag positive women were able to bring back the supplementary virological assessment within a period less than one month. Conclusion: According to our work the virologic profile of positive HBs Ag in pregnant women in Cote d’Ivoire is characterized by an important viral replication objectified by a high viral load in about 23% pregnant women, a negativity of HBe antigen in 96.6% of them.

Association of Cytokines with Alanine Aminotransferase, Hepatitis B Virus Surface Antigen and Hepatitis B Envelope Antigen Levels in Chronic Hepatitis B

Background： Cytokines play an important role in occorrence and recovery of hepatitis B virus （HBV） infection. The aim of this study was to investigate the changes ofcytokines concentration and its correlation to alanine aminotransferase （ALT）, HBV deoxyribonucleic acid （HBV-DNA）, hepatitis B envelope antigen （HBeAg）, and HBV surface antigen （HBsAg） in the development of chronic hepatitis B （CHB）. Methods： Thirteen healthy individuals （HI）, 30 chronic HBV-infected patients in immune tolerant （IT） phase, and 55 CHB patients were enrolled between August 2015 and May 2017. The peripheral blood samples were collected from all individuals. Tile levels of interferon （IFN）-α2, interleukin （IL）-10, transforming growth factor （TGF）-β1, HBV-DNA, HBsAg, and HBeAg and liver function were measured. The quantitative determinations of cytokines levels, including I FN-ct2, IL-10, and TGF-[31 were performed using Luminex multiplex technology. The correlation of cytokines to ALT, HBV-DNA, HBsAg, and HBeAg was analyzed by linear regression analysis. Results： IFN-ct2 levels were similar between HI and IT groups （15.35 [5.70, 67.65] pg/ml vs. 15.24 [4.07, 30.73] pg/ml, Z = -0.610, P - 0.542）, while it elevated significantly in CH B group （35.29 [ 15.94, 70.15] pg/ml vs. 15.24 [4.07, 30.73] pg/ml; Z = -2.522, P = 0.012）. Compared with HI group （3.73 [2.98, 11.92] pg/ml）, IL-10 concentrations in IT group （5.02 [2,98, 10.11] pg/ml）, and CHB group （7.48 [3. I 0, 18.00] pg/ml） slightly increased （X^2 = 2.015, P - 0.365）, and there was no significant difference between IT and CHB group （Z =- 1.419, P = 0.156）. The TGF-β1 levels among HI （3.59 ±0.20 pg/ml）, IT （3.62 ±0.55 pg/ml）, and CHB groups （3.64±0.30 pg/ml） were similar （X^2=2.739, P = 0.254）. In all chronic HBV-infected patients （including patients in IT and CHB groups）, the elevation of IFN-α2 level was significantly associated with ALT level （β = 0.389, t = 2.423, P = 0.018）, and was also negatively correlated to HBV-DNA load （β = -0.358, t=-2.308, P = 0.024）, HBsAg （β = -0.359, t = -2.288, P = 0.025）, and HBeAg contents （β = -0.355, t = -2.258, P = 0.027）. However, when both ALT level and cytokines were included as independent variable, HBV-DNA load, HBsAg, and HBeAg contents were only correlated to ALT level （[β= -0.459, t = -4.225, P = 0.000; β = -0.616, t = -6.334, P = 0.000; and β = -0.290, t = -2.433, P = 0.018; respectively）. Conclusions： IFN-α2 elevation was associated with ALT level in patients with chronic HBV infection. However, in CHB patients, only ALT level was correlated to HBV-DNA, HBsAg and HBeAg contents.

Epigallocatechin gallate inhibits HBV DNA synthesis in a viral replication-inducible cell line

AIM:To analyze the antiviral mechanism of Epigallocatechin gallate(EGCG)against hepatitis B virus(HBV) replication.METHODS:In this research,the HBV-replicating cell line HepG2.117 was used to investigate the antiviral mechanism of EGCG.Cytotoxicity of EGCG was analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Hepatitis B virus e antigen(HBeAg)and hepatitis B virus surface antigen(HBsAg)in the supernatant were detected by enzyme-linked immunosorbent assay.Precore mRNA and pregenomic RNA(pgRNA) levels were determined by semi-quantitative reverse transcription polymerase chain reaction(PCR)assay.The effect of EGCG on HBV core promoter activity was measured by dual luciferase reporter assay.HBV covalently closed circular DNA and replicative intermediates of DNA were quantified by real-time PCR assay.RESULTS:When HepG2.117 cells were grown in the presence of EGCG,the expression of HBeAg was suppressed,however,the expression of HBsAg was not affected.HBV precore mRNA level was also downregulated by EGCG,while the transcription of precore mRNA was not impaired.The synthesis of both HBV covalently closed circular DNA and replicative intermediates of DNA were reduced by EGCG treatment to a similar extent,however,HBV pgRNA transcripted from chromosome-integrated HBV genome was not affected by EGCG treatment,indicating that EGCG targets only replicative intermediates of DNA synthesis.CONCLUSION:In HepG2.117 cells,EGCG inhibits HBV replication by impairing HBV replicative intermediates of DNA synthesis and such inhibition results in reduced production of HBV covalently closed circular DNA.

Enhancement of humoral immune responses to HBsAg by heat shock protein gp96 and its N-terminal fragment in mice

AIM: Most studies on the immune effect of gp96 were focused on its enhancement of CTLs. It is interesting to know whether gp96 could influence the humoral immune response, and whether the recombinant N-terminal fragment of gp96 could substitute native gp96 to stimulate the immune system.METHODS: gp96 isolated from livers of normal mice and its N-terminal fragment (amino acid 22-355) expressed in E coli were used for immunization of BALb/c mice. Eight groups of mice received one of the following regiments subcutaneously in 100 μL phosphate buffered saline (PBS)at an interval of 3 wk. Group 1: PBS only; group 2:gp96 only; group 3: N-terminal fragment only; group 4: HBsAg only; group 5: HBsAg+gp96; group 6: HBsAg+N-terminalfragment; group 7: HBsAg+incomplete Freud's adjuvant; group 8: HBsAg+N-terminal fragment (95 ℃ heated for 30 min). Serum anti-HBsAg antibody levels were assayed by ELISA. CTL responses in splenocytes were analyzed by ELISPOT after the last vaccination.RESULTS: The average titer of serum anti-HBsAg antibodyin the mice immunized with HBsAg together with gp96 or its N-terminal fragment were much higher than those immunized with HBsAg alone detected by ELISA. The cellular immune response of the mice immunized with HBsAg together with gp96 or its N-terminal fragment was not different with those immunized with HBsAg alone measured by ELISPOT assay.CONCLUSION: gp96 or its N-terminal fragment greatly improved humoral immune response induced by HBsAg, but failed to enhance the CTL response, which demonstrated the potential of using gp96 or its N-terminal fragment as a possible adjuvant to augment humoral immune response against HBV infection.