Search results for "Core antigen"
showing 10 items of 46 documents
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 …
Pre-core mutants of hepatitis B virus in patients receiving immunosuppressive treatment after orthotopic liver transplantation.
1996
Orthotopic liver transplantation (OLT) is a possible treatment for acute or chronic liver failure due to hepatitis B virus (HBV) infection, but reinfection of the graft can be a serious complication. The aim of this study was to monitor HBV markers, to analyse pre-core-/core-mutations as well as to identify the viral population causing reinfection after OLT, and to investigate the emergence or disappearance of these mutants in patients receiving immunosuppressive treatment. Fifty-four pre-and posttransplant serum samples of 17 patients were analysed. All patients underwent OLT for HBV-related liver disease and had HBV-DNA before and after OLT. Total DNA was extracted from all sera and a 240…
e System and intrahepatocelullar HBcAG and HBsAG in HBsAG positive patients with liver diseases and healthy carriers.
1977
Patients with hepatitis-B surface antigen positive liver diseases and healthy carriers were studied for the presence of e-antigen and anti-e as well as for intrahepatocellular HBsAG and hepatitis-B core antigen. The e-antigen was demonstrated in 9 out of 12 patients with chronic perisitent hepatitis, in 15 out of 39 patients with chronic active hepatitis, in 3 out of 40 patients with acute type B hepatitis, and in 2 out of 9 patients with a protracted course of type B hepatitis. No e-antigen was found in healthy HBsAG carriers nor in patients with complete recovery from type B hepatitis one year after onset of the disease. Anti-e was detected in 24 out of 61 healthy HBsAG carriers with a no…
Lack of correlation between serum anti-HBcore detectability and hepatocellular carcinoma in patients with HCV-related cirrhosis
2008
BACKGROUND: While the likelihood of developing hepatocellular carcinoma (HCC) in patients coinfected with both HBV and HCV is increased, the role of previous exposure to HBV as a risk factor associated with tumor occurrence in subjects with HCV-related cirrhosis has not been fully investigated. AIM: To assess whether serum anti-HBc positivity, as a marker of previous HBV exposure, is associated with HCC development in HCV-related positive, hepatitis B surface antigen (HBsAg) negative patients with cirrhosis treated with alfa-interferon (IFN) monotherapy. PATIENTS AND: A database including 883 consecutive patients (557 men, mean age 54.7 yr) with histologically METHODS: proven cirrhosis trea…
Hepatitis C virus infection as a risk factor for hepatocellular carcinoma in patients with cirrhosis. A case-control study.
1992
Objective To determine whether chronic hepatitis C virus (HCV) infection is an independent risk factor for hepatocellular carcinoma and whether it increases the cirrhosis-related risk for hepatocellular carcinoma. Design Two pair-matched case-control studies. Setting A referral-based hospital. Patients In study I, 212 patients with hepatocellular carcinoma (197 of whom had known underlying cirrhosis) were compared with controls who had chronic nonhepatic diseases. In study II, the 197 patients with hepatocellular carcinoma and cirrhosis were compared with 197 pair-matched controls who had cirrhosis but not hepatocellular carcinoma. Measurements Levels of antibody to HCV (anti-HCV), hepatiti…
Patients With Isolated Hepatitis B Core Antibody: Has the Time Come to Vaccinate?
2017
International audience
A molecular assembly system that renders antigens of choice highly repetitive for induction of protective B cell responses.
2002
Virus like particles (VLPs) are known to induce potent B cell responses in the absence of adjuvants. Moreover, epitope-specific antibody responses may be induced by VLPs that contain peptides inserted in their immunodominant regions. However, due to steric problems, the size of the peptides capable of being incorporated into VLPs while still permitting capsid assembly, is rather limited. While peptides genetically fused to either the N- or C-terminus of VLPs present fewer assembly problems, the immune responses obtained against such epitopes are often limited, most likely because the epitopes are not optimally exposed. In addition, such particles may be less stable in vivo. Here, we show th…
New chimaeric hepatitis B virus core particles carrying hantavirus (serotype Puumala) epitopes: immunogenicity and protection against virus challenge
1999
Virus-like particles generated by the heterologous expression of virus structural proteins are able to potentiate the immunogenicity of foreign epitopes presented on their surface. In recent years epitopes of various origin have been inserted into the core antigen of hepatitis B virus (HBV) allowing the formation of chimaeric HBV core particles. Chimaeric core particles carrying the 45 N-terminal amino acids of the Puumala hantavirus nucleocapsid protein induced protective immunity in bank voles, the natural host of this hantavirus. Particles applied in the absence of adjuvant are still immunogenic and partially protective in bank voles. Although a C-terminally truncated core antigen of HBV…
Chimaeric HBV core particles carrying a defined segment of Puumala hantavirus nucleocapsid protein evoke protective immunity in an animal model
1998
Abstract Hantaviruses are rodent-born agents which are pathogenic in humans causing haemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome. To induce a protective immunity against a European hantavirus (Puumala) we constructed chimaeric hepatitis B virus (HBV) core particles carrying defined fragments of the Puumala virus nucleocapsid protein. After immunisation of bank voles, the natural host of Puumala virus, with core particles possessing an insertion of the N-terminal part of Puumala virus nucleocapsid protein, four of five animals were protected against subsequent virus challenge. The results show that the major protective region of the nucleocapsid protein is located …
An amino-terminal segment of hantavirus nucleocapsid protein presented on hepatitis B virus core particles induces a strong and highly cross-reactive…
2004
AbstractPreviously, we have demonstrated that hepatitis B virus (HBV) core particles tolerate the insertion of the amino-terminal 120 amino acids (aa) of the Puumala hantavirus nucleocapsid (N) protein. Here, we demonstrate that the insertion of 120 amino-terminal aa of N proteins from highly virulent Dobrava and Hantaan hantaviruses allows the formation of chimeric core particles. These particles expose the inserted foreign protein segments, at least in part, on their surface. Analysis by electron cryomicroscopy of chimeric particles harbouring the Puumala virus (PUUV) N segment revealed 90% T = 3 and 10% T = 4 shells. A map computed from T = 3 shells shows additional density splaying out …