scholarly journals E-cadherin binds glycosylated sodium-taurocholate cotransporting polypeptide to facilitate hepatitis B virus entry

2019 ◽  
Author(s):  
Qin Hu ◽  
Fei-Fei Zhang ◽  
Liang Duan ◽  
Bo Wang ◽  
Pu Li ◽  
...  
Keyword(s):  
Public Health ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Sodium Taurocholate ◽  
Hbv Infection ◽  
Host Cells ◽  
Heparg Cells ◽  
B Virus ◽  
Hepatocyte Polarity ◽  
E Cadherin

AbstractHepatitis B virus (HBV) continues to pose a serious public health risk and is one of the major causes of chronic liver disease and hepatocellular carcinoma. Current antiviral therapy does not effectively eradicate HBV and, thus, further investigation into the mechanisms employed by HBV to allow for invasion of host cells, is critical for the development of novel therapeutic agents. Sodium-taurocholate cotransporting polypeptide (NTCP) has been identified as a functional receptor for HBV. However, the specific mechanism by which HBV and NTCP interact remains unclear. Herein we show that the expression of E-cadherin was upregulated in cells expressing HBV, while knockdown of E-cadherin in HepG2-NTCP cells, HepaRG cells and primary human hepatocytes served to significantly inhibit infection by HBV and HBV pseudotyped particles. Alternatively, exogenous E-cadherin expression was found to significantly enhance HBV uptake by HepaRG cells. Further, mechanistic studies identified glycosylated NTCP localized to the cell membrane via E-cadherin binding, which subsequently allowed for more efficient binding between NTCP and the preS1 of the large HBV surface proteins. E-cadherin was also found to play a key role in establishing and maintaining hepatocyte polarity, which is essential for efficient HBV infection. These observations suggest that E-cadherin facilitates HBV entry through regulation of NTCP distribution and hepatocyte polarity.Author SummaryHepatitis B Virus (HBV) still seriously endangers public health. It is very important to understand the mechanism of HBV invading host cells for developing new therapy target. Sodium-taurocholate cotransporting polypeptide (NTCP) is the key receptor mediating HBV invasion, while other molecules also exhibit important roles in ensuring efficient and productive HBV infection. This study reports that E-cadherin facilitates HBV entry by directly interacting with glycosylated NTCP to mediate its distribution on the hepatocyte membrane and also affects the efficacy of HBV invasion by influncing hepatocyte polarity.

NTCP oligomerization occurs downstream of the NTCP-EGFR interaction during hepatitis B virus internalization

2021 ◽  
Author(s):  
Kento Fukano ◽  
Mizuki Oshima ◽  
Senko Tsukuda ◽  
Hideki Aizaki ◽  
Mio Ohki ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Bile Acid ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Viral Entry ◽  
Sodium Taurocholate ◽  
Growth Factor Receptor ◽  
Host Cells ◽  
B Virus ◽  
Epidermal Growth

Sodium taurocholate cotransporting polypeptide (NTCP) is a receptor that is essential for hepatitis B virus (HBV) entry into the host cell. A number of HBV entry inhibitors targeting NTCP have been reported to date; these inhibitors have facilitated a mechanistic analysis of the viral entry process. However, the mechanism of HBV internalization into host cells after interaction of virus with NTCP remains largely unknown. Recently, we reported that troglitazone, a thiazolidinedione derivative, specifically inhibits both HBV internalization and NTCP oligomerization, resulting in inhibition of HBV infection. Here, using troglitazone as a chemical probe to investigate entry process, the contribution of NTCP oligomerization to HBV internalization was evaluated. Using surface plasmon resonance and transporter kinetics, we found that troglitazone directly interacts with NTCP and non-competitively interferes with NTCP-mediated bile acid uptake, suggesting that troglitazone allosterically binds to NTCP, rather than to the bile acid-binding pocket. Additionally, alanine scanning mutagenesis showed that a mutation at phenylalanine 274 of NTCP (F274A) caused a loss of HBV susceptibility and disrupted both the oligomerization of NTCP and HBV internalization without affecting viral attachment to the cell surface. An inhibitor of the interaction between NTCP and epidermal growth factor receptor (EGFR), another host cofactor essential for HBV internalization, impeded NTCP oligomerization. Meanwhile, co-immunoprecipitation analysis revealed that neither troglitazone nor the F274A mutation in NTCP affect the NTCP-EGFR interaction. These findings suggest that NTCP oligomerization is initiated downstream of the NTCP-EGFR interaction, and then triggers HBV internalization. This study provides significant insight into the HBV entry mechanisms. Importance Hepatitis B virus (HBV) infection is mediated by a specific interaction with sodium taurocholate cotransporting polypeptide (NTCP), a viral entry receptor. Although the virus-receptor interactions are believed to trigger viral internalization into host cells, the exact molecular mechanisms of HBV internalization are not understood. In this study, we revealed the mode of action whereby troglitazone, a specific inhibitor of HBV internalization, impedes NTCP oligomerization, and identified NTCP phenylalanine 274 as a residue essential for this oligomerization. We further analyzed the association between NTCP oligomerization and HBV internalization, a process that is mediated by epidermal growth factor receptor (EGFR), another essential host cofactor for HBV internalization. Our study provides critical information on the mechanism of HBV entry, and suggests that oligomerization of the viral receptor serves as an attractive target for drug discovery.

scholarly journals Recent advances in understanding and diagnosing hepatitis B virus infection

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2243 ◽  
Author(s):  
Slim Fourati ◽  
Jean-Michel Pawlotsky
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Immune Modulation ◽  
Hepatitis B Surface Antigen ◽  
Sodium Taurocholate ◽  
Hbv Infection ◽  
New Drugs ◽  
Recent Advances ◽  
Hbsag Detection ◽  
B Virus

Hepatitis B virus (HBV) infects approximately 240 million individuals worldwide. Recent advances in the virology, immunopathogenesis, and diagnosis of HBV infection are summarized in this review article. The identification of a hepatocyte-specific cellular receptor for HBV, the sodium taurocholate co-transporting polypeptide (NTCP), made it possible to develop reliable cell culture systems and better understand the early steps of the viral lifecycle. Viral and host factors involved in covalently closed circular DNA synthesis, stability, and transcriptional regulation have also been identified and provide potential targets for new drugs. Based on recent evidence showing trained immunity in immune-tolerant patients, the immune tolerance and immune clearance phases have been renamed the non-inflammatory and inflammatory phases, respectively. New diagnostic and monitoring tools are now available, including rapid diagnostic tests for hepatitis B surface antigen (HBsAg) detection, HBsAg quantification assays, anti-HBc antibody quantification assays, an HBV core-related antigen (HBcrAg) quantification test, new HBV DNA detection and quantification assays, and an HBV RNA quantification test. Their clinical utility is under study. Finally, new antiviral and immune modulation approaches are in the preclinical or early clinical developmental stages, with the goal to achieve functional cure or ideally (if possible) eradication of HBV infection.

scholarly journals Establishment of a novel hepatitis B virus culture system using immortalized human hepatocytes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuichi Akahori ◽  
Hiroki Kato ◽  
Takashi Fujita ◽  
Kohji Moriishi ◽  
Yasuhito Tanaka ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cell Lines ◽  
Culture System ◽  
Sodium Taurocholate ◽  
Three Dimensional ◽  
Human Hepatocytes ◽  
Host Cells ◽  
B Virus ◽  
Almost All

AbstractRecent development of hepatitis B virus (HBV) culture systems has made it possible to analyze the almost all steps of the viral life cycle. However, the reproducibility of interaction between HBV and host cells seemed inaccurate in those systems because of utilization of cancer cell lines with a difference from hepatocytes in the majority of cases. In this study, in order to resolve this point, a novel HBV culture system using non-cancer-derived immortalized human hepatocytes derived cell lines, producing exogenous human sodium taurocholate cotransporting polypeptide, was developed. One of the cell clones, E/NtG8 cells, was permissive to both blood-borne HBV (HBVbb) and culture-derived recombinant HBV when cultured in the three-dimensional condition. Furthermore, the production of infectious HBV particles, which showed the similar physicochemical properties to HBVbb, was observed for about a month after HBVbb infection in this system, suggesting that it may reproduce whole steps of the HBV lifecycle under the condition analogous to human liver cells infected with HBV. This system seemed to contribute not only to find novel interactions between HBV and host cells but also to understand mechanism of HBV pathogenesis.

scholarly journals Interactions between hepatitis B virus and aflatoxin B1: effects on p53 induction in HepaRG cells

2012 ◽  
Vol 93 (3) ◽  
pp. 640-650 ◽  
Author(s):  
Myriam Lereau ◽  
Doriane Gouas ◽  
Stéphanie Villar ◽  
Ahmad Besaratinia ◽  
Agnès Hautefeuille ◽  
...  
Keyword(s):  
Risk Factors ◽  
Dna Damage ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cell Line ◽  
Hbv Infection ◽  
Hbv Replication ◽  
Heparg Cell Line ◽  
Heparg Cells ◽  
B Virus

Infection by hepatitis B virus (HBV) and dietary exposure to aflatoxin B1 (AFB1) are the main risk factors for the development of chronic liver disease and hepatocellular carcinoma (HCC). How these factors cooperate is still largely unknown. AFB1 activation leads to DNA adduction and mutagenesis, with a specific mutation at codon 249 in TP53 (p.R249S). So far, only limited studies have addressed the effects of AFB1 on HBV replication. We have analysed the effects of both risk factors on p53 induction during HBV infection in HepaRG, a cell line with hepatocyte-like morphology that metabolizes AFB1 and supports HBV infection. Exposure to AFB1 up to 5 µM induced a downregulation of HBV replication after 48 h, as measured by a decrease in viral antigens in the culture medium (HBsAg, HBeAg and large envelope protein) and in intracellular levels of HBV transcripts, DNA and HBsAg. Conversely, HBV infection did not significantly modify AFB1-DNA adduct formation or repair as assessed by immunodot-blot assay, and the induction of p53 in response to AFB1 was similar in infected and non-infected HepaRG cells. Overall, our results suggest that AFB1 exposure decreases HBV replication, whereas DNA damage by AFB1 and subsequent p53 induction is not affected by the presence of the virus. Thus, in HepaRG cell line, AFB1 and HBV do not cooperate to increase DNA damage by AFB1. Further studies on the effects of both factors in a context of chronicity are needed to better understand synergistic effects.

Control of Hepatitis B: To Be or Not To Be?

PEDIATRICS ◽  
1992 ◽  
Vol 90 (2) ◽  
pp. 274-277
Author(s):  
CAROLINE BREESE HALL ◽  
NEAL A. HALSEY
Keyword(s):  
Public Health ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Infectious Diseases ◽  
American Academy ◽  
Hbv Infection ◽  
New Approach ◽  
American Academy Of Pediatrics ◽  
B Virus ◽  
Universal Infant

The needs of children should not be made to wait. —John F. Kennedy, 1963 The recent recommendations of the American Academy of Pediatrics (AAP) Committee on Infectious Diseases and the Immunization Practices Advisory Committee of the Centers for Disease Control to immunize all infants against hepatitis B virus (HBV) infection have engendered concerns and questions which should not eclipse the import and intent of these recommendations.1,2 Behind these statements lay much deliberation and expertise drawn from those in pediatrics, medicine, infectious diseases, and public health. The undeniable conclusions of both committees are that control of HBV infection and its consequences (1) is necessary, (2) requires a new approach, and (3) must include universal infant immunization and should include immunization of adolescents whenever resources permit.

scholarly journals N-Linked Glycosylation Is Not Essential for Sodium Taurocholate Cotransporting Polypeptide To Mediate Hepatitis B Virus Infection In Vitro

2018 ◽  
Vol 92 (15) ◽  
Author(s):  
Jiwon Lee ◽  
Li Zong ◽  
Alexander Krotow ◽  
Yanli Qin ◽  
Lucy Jia ◽  
...  
Keyword(s):  
Cell Culture ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Surface Antigen ◽  
Hepg2 Cells ◽  
Hepatitis B Surface Antigen ◽  
Sodium Taurocholate ◽  
Wild Type ◽  
Heparg Cells ◽  
B Virus

ABSTRACT Sodium taurocholate cotransporting polypeptide (NTCP) has been identified as a hepatitis B virus (HBV) receptor, and its overexpression in HepG2 cell lines leads to efficient secretion of hepatitis B e antigen (HBeAg) following challenge with a large dose of cell culture-derived HBV (cHBV) particles. However, NTCP-reconstituted HepG2 cells are inefficiently infected by patient serum-derived HBV (sHBV) and release very little hepatitis B surface antigen (HBsAg) following cHBV infection, unlike differentiated HepaRG cells, which are naturally susceptible to both cHBV and sHBV particles. Here, we investigated whether NTCP could explain the different behaviors of the two cell types. Endogenous NTCP protein from differentiated HepaRG cells was unglycosylated despite wild-type coding sequence. HepaRG cells stably transfected with an epitope-tagged NTCP expression construct displayed higher sHBV but not cHBV susceptibility than cells transfected with the null mutant. Tagged NTCP introduced to both HepG2 and HepaRG cells was glycosylated, with N5 and N11 being sites of N-linked glycosylation. Mutating N5, N11, or both did not alter cell surface availability of NTCP or its subcellular localization, with both the singly glycosylated and nonglycosylated forms still capable of mediating cHBV infection in HepG2 cells. In conclusion, nonglycosylated NTCP is expressed by differentiated HepaRG cells and capable of mediating cHBV infection in HepG2 cells, but it cannot explain differential susceptibility of HepaRG and HepG2/NTCP cells to cHBV versus sHBV infection and different HBsAg/HBeAg ratios following cHBV infection. The responsible host factor(s) remains to be identified. IMPORTANCE HBV can infect differentiated HepaRG cells and also HepG2 cells overexpressing NTCP, the currently accepted HBV receptor. However, HepG2/NTCP cells remain poorly susceptible to patient serum-derived HBV particles and release very little hepatitis B surface antigen following infection by cell culture-derived HBV. We found differentiated HepaRG cells expressed nonglycosylated NTCP despite a wild-type coding sequence. NTCP introduced to HepG2 cells was glycosylated at two N-linked glycosylation sites, but mutating either or both sites failed to prevent infection by cell culture-derived HBV or to confer susceptibility to serum-derived HBV. Overexpressing NTCP in HepRG cells did not increase infection by cell culture-derived HBV or distort the ratio between the two viral antigens. These findings suggest that host factors unique to HepaRG cells are required for efficient infection by serum-derived HBV, and factors other than NTCP contribute to balanced viral antigen production following infection by cell culture-derived HBV.

scholarly journals Persistence of Anti-HBs Antibody and Immunological Memory in Healthy Individuals Vaccinated with Hepatitis B Vaccine

1970 ◽  
Vol 1 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Bidhan Chakraborty ◽  
Tanvir Bashar ◽  
Konok Roy ◽  
Rashed Noor ◽  
M Majibur Rahman
Keyword(s):  
Public Health ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Age Groups ◽  
Immunological Memory ◽  
Hbv Infection ◽  
Healthy Individuals ◽  
Protective Level ◽  
B Virus ◽  
The World

Hepatitis B virus (HBV) infection is one of the major public health problems in the world. It is estimated that there are three hundred million HBV carriers and around one million deaths annually due to HBV infection worldwide. Vaccination is considered to be the best solution to this problem. The present study was conducted to investigate the efficacy of the vaccine administered against hepatitis B and to reveal the immunological memory against the vaccine. Samples were taken from both male (74 individuals) and female (37 individuals) from different age groups ranging from three to sixty three years. Among the population studied, both good (63.06%) and hypo (36.94%) responders were found. All the individuals (100%) showed a satisfactory result having an anti-HBs antibody titer above the protective level (≥ 10 IU/L).DOI: http://dx.doi.org/10.3329/sjm.v1i1.9101  Stamford Journal of Microbiology, Vol.1(1), July 2011, p.37-41

scholarly journals Involvement of Host ATR-CHK1 Pathway in Hepatitis B Virus Covalently Closed Circular DNA Formation

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jun Luo ◽  
Laurie Luckenbaugh ◽  
Hui Hu ◽  
Zhipeng Yan ◽  
Lu Gao ◽  
...  
Keyword(s):  
Dna Damage ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Viral Replication ◽  
Host Cell ◽  
Hbv Infection ◽  
Host Cells ◽  
B Virus ◽  
Cellular Dna ◽  
Dna Processing

ABSTRACT The covalently closed circular (CCC) DNA of hepatitis B virus (HBV) functions as the only viral transcriptional template capable of producing all viral RNA species and is essential to initiate and sustain viral replication. CCC DNA is converted from a relaxed circular (RC) DNA, in which neither of the two DNA strands is covalently closed. As RC DNA mimics damaged cellular DNA, the host cell DNA damage repair (DDR) system is thought to be responsible for HBV CCC DNA formation. The potential role of two major cellular DDR pathways, the ataxia telangiectasia mutated (ATM) pathway and the ATM and Rad3-related (ATR) pathway, in HBV CCC DNA formation was thus investigated. Inhibition, or expression knockdown, of ATR and its downstream signaling factor CHK1, but not of ATM, decreased CCC DNA formation during de novo HBV infection, as well as intracellular CCC DNA amplification, when RC DNA from extracellular virions and intracellular nucleocapsids, respectively, is converted to CCC DNA. Furthermore, a novel RC DNA processing product with 5′ truncated minus strands was detected when the ATR-CHK1 pathway was inhibited, further indicating that this pathway controls RC DNA processing during its conversion to CCC DNA. These results provide new insights into how host cells recognize and process HBV RC DNA in order to produce CCC DNA and have implications for potential means to block CCC DNA production. IMPORTANCE Hepatitis B virus (HBV) chronically infects hundreds of millions of people and remains a major cause of viral hepatitis, cirrhosis, and liver cancer. HBV persistence is sustained by a viral nuclear episome that directs all viral gene expression needed to support viral replication. The episome is converted from an incomplete DNA precursor in viral particles in an ill-understood process. We report here that the incomplete DNA precursor is recognized by the host cell in a way similar to the sensing of damaged cellular DNA for subsequent repair to form the nuclear episome. Intense efforts are ongoing to develop novel antiviral strategies to eliminate CCC DNA so as to cure chronic HBV infection. Our results here provide novel insights into, and suggest novel ways of perturbing, the process of episome formation. Furthermore, our results inform mechanisms of cellular DNA damage recognition and repair, processes essential for normal cell growth.

scholarly journals Hepatitis B Virus Infection of a Mouse Hepatic Cell Line Reconstituted with Human Sodium Taurocholate Cotransporting Polypeptide

2016 ◽  
Vol 90 (9) ◽  
pp. 4827-4831 ◽  
Author(s):  
Florian A. Lempp ◽  
Bingqian Qu ◽  
Yong-Xiang Wang ◽  
Stephan Urban
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cell Line ◽  
Sodium Taurocholate ◽  
Hbv Infection ◽  
Hepatitis B Virus Infection ◽  
Hepatic Cells ◽  
Mouse Liver Cell ◽  
B Virus ◽  
Mouse Hepatocytes

Hepatitis B virus (HBV) enters hepatocytes via its receptor, human sodium taurocholate cotransporting polypeptide (hNTCP). So far, HBV infection has been achieved only in human hepatic cells reconstituted with hNTCP and not in cells of mouse origin. Here, the first mouse liver cell line (AML12) which gains susceptibility to HBV upon hNTCP expression is described. Thus, HBV infection of receptor-expressing mouse hepatocytes does not principally require a human cofactor but can be triggered by endogenous murine determinants.

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