Search results for "Hepatitis B viru"

HBV recurrence after HCV clearance on DAAs: Sometimes they come back

2017

Biological standards for hepatitis B virus assays.

1992

Hepatitis B subviral envelope particles use the COPII machinery for intracellular transport via selective exploitation of Sec24A and Sec23B

2020

Hepatitis B virus (HBV) is a leading cause of liver disease. Its success as a human pathogen is related to the immense production of subviral envelope particles (SVPs) contributing to viral persistence by interfering with immune functions. To explore cellular pathways involved in SVP formation and egress, we investigated host-pathogen interactions. Yeast-based proteomics revealed Sec24A, a component of the coat protein complex II (COPII), as an interaction partner of the HBV envelope S domain. To understand how HBV co-opts COPII as a proviral machinery, we studied roles of key Sec proteins in HBV-expressing liver cells. Silencing of Sar1, Sec23, and Sec24, which promote COPII assembly conco…

Immune Reactions in Liver Diseases

1983

Chronic hepatitis is a heterogeneous syndrome with different underlying etiologies. Viruses (hepatitis B virus, non-A, non-B viruses), drugs and even alcohol are regarded as etiological agents. A further subgroup is autoimmune-type chronic hepatitis in which an immunogenetic predisposition is of major importance. Primary biliary cirrhosis has to be separated from these subgroups of chronic hepatitis.

Deletions in the hepatitis B virus small envelope protein: effect on assembly and secretion of surface antigen particles

1992

The small envelope S protein of hepatitis B virus carrying the surface antigen has the unique property of mobilizing cellular lipids into empty envelope particles which are secreted from mammalian cells. We studied the biogenesis of such particles using site-directed mutagenesis. In this study, we describe the effect of deletions in the N-terminal hydrophobic and hydrophilic domains of the S protein. Whereas short overlapping deletions of hydrophilic sequences flanking the first hydrophobic domain were tolerated, larger deletions of the same sequences were not. Conversely, the hydrophilic region preceding the second hydrophobic domain was not permissive for even short deletions. Deletion of…

Priming of cytotoxic T cell responses to exogenous hepatitis B virus core antigen is B cell dependent

2003

The hepatitis B virus (HBV) core antigen (HBcAg) has a unique ability to bind a high frequency of naive human and murine B cells. The role of HBcAg-binding naive B cells in the immunogenicity of HBcAg is not clear. The HBcAg-binding properties of naive B cells were characterized using HBcAg particles with mutated spike region (residues 76-85) sequences. Deletion of residues 76-85 (HBcDelta76-85) destroyed naive B cell binding, whereas deletion of residues 79-85 did not. HBcAg particles with an Ile instead of the natural Ala at position 80 did not bind naive B cells, whereas reversion of Ile80--Ala restored B cell binding. Destroying the B cell-binding ability of HBcAg had a marginal effect …

2014

The hepatitis B virus (HBV) is an enveloped DNA virus that replicates via reverse transcription of its pregenomic RNA (pgRNA). Budding of HBV is supposed to occur at intracellular membranes and requires scission functions of the endosomal sorting complex required for transport (ESCRT) provided by ESCRT-III and VPS4. Here, we have investigated the impact of the upstream-acting ESCRT-I and ESCRT-II complexes in HBV morphogenesis. RNA interference knockdown of the ESCRT-I subunits TSG101 and VPS28 did not block, but rather stimulate virus release. In contrast, RNAi-mediated depletion of the ESCRT-II components EAP20, EAP30 and EAP45 greatly reduced virus egress. By analyzing different steps of…

Semiquantitative assessment of pre-core stop-codon mutant and wildtype hepatitis B virus during the course of chronic hepatitis B using a new PCR-bas…

1996

In most patients with chronic hepatitis B positive for antibodies (anti-HBe) to HBe antigen (HBeAg), a pre-core mutant hepatitis B virus (HBV) with a point-mutation at nt. 1896 can be isolated. Clinical significance of the mutant virus in chronic hepatitis B is not proven yet, and screening of large numbers of sera during different clinical courses of numerous patients is necessary. We therefore aimed to develop a fast and reliable assay, that allows to discriminate wildtype from nt. 1896 G-->A mutant HBV and to determine the ratio of mutant and wildtype HBV in patients' sera. A mutation specific polymerase chain reaction (ms PCR) with new primers served to distinguish nt. 1896 G-->A mutant…

Persistent expression of hepatitis C virus genome in primary tumor and adrenal metastasis of a hepatocellular carcinoma developed in a non-cirrhotic …

1996

To the Editor: There is increasing evidence that chronic infection with hepatitis C virus (HCV) is a risk factor for hepatocellular carcinoma (HCC) in patients seronegative for hepatitis B virus (HBV) surface antigen (HBsAg). In western countries, HCCs occur in anti-HCV positive patients mostly in association with cirrhosis, which can be considered as a precancerous condition (1). However, there are rare cases of HCC that were found in anti-HCV positive patients without pre-existing liver cirrhosis (2). We report here the detection of HCV RNA in a primary HCC derived from an HCV-infected patient with a non-cirrhotic liver and its persistent expression in an adrenal metastasis that developed…

Macrophagic myofasciitis in a 3-month-old child

2015

Macrophagic myofasciitis (MMF) is a rare inflammatory myopathy which occurs after injection of aluminium-containing vaccines against hepatitis B virus (HBV), hepatitis A virus, and tetanus toxoid. Most of the cases reported are from France and are adult patients. We report a rare case of MMF in a 3-month-old male child of Indian origin. He was immunized for HBV at birth after which he developed generalized hypotonia, and central nervous system and peripheral nervous system manifestations at 1 month of age. Muscle biopsy showed typical features of MMF and aluminium could be detected in the muscle biopsy macrophages by ultrastructural examination and LAMMA technique. Our case is the youngest …