mutations in the human hepatitis b virus (hbv) genome contribute to its escape from host immune surveillance and result in persistent infections. the aim of this study was to characterize the molecular variations of the surface gene and protein in chronically-infected patients from the southern part of iran. the  surface  genes  from  12  hbv  chronic  carriers  were  amplified, sequenced  and ...

BACKGROUND/AIMS Clearance of hepatitis B virus (HBV) is characterised by a strong cytotoxic T cell response. Persistence of HBV in chronic hepatitis B carriers may be related to failure of this response. The aim of this study was to determine whether HLA class I restricted cytotoxic T lymphocyte (CTL) responses persist in anti-hepatitis B e (HBe) positive / HBV DNA negative individuals, and to ...

hepatitis b vaccination is safe and effective, although breakthrough infection occasionally occurs in those who receive the vaccine and hepatitis b immunoglobulin (hbig) prophylaxis. sequence variation in their antigenic regions is one of the most powerful strategies that are used by viruses to escape recognition by b and t cell-mediated immune responses. the aim of this study was to explore th...

BACKGROUND Escape mutations potentially allow viruses to avoid detection and clearance by the host immune system and may represent a mechanism through which infections may persist in some patients. The association of the mutations in the HBcAg gene with Hepatitis B asymptomatic carriers (ASC) has not been studied adequately. The current study was aimed to investigate HBcAg18-27 CTL epitope muta...

Increased clinical and scientific scrutiny is being applied to hepatitis B virus (HBV), with focus on the development of new therapeutic approaches, ultimately aiming for cure. Defining the optimum natural CD8+ T cell immune responses that arise in HBV, mediated by HLA class I epitope presentation, may help to inform novel immunotherapeutic strategies. Therefore, we have set out to develop a co...

Distribution of hepatitis B virus (HBV) genotypes/subgenotypes is geographically and ethnologically specific. In the Indonesian archipelago, HBV genotype C (HBV/C) is prevalent with high genome variability, reflected by the presence of 13 of currently existing 16 subgenotypes. We investigated the association between HBV/C molecular characteristics with host ethnicity and geographical distributi...

To control hepatitis B virus (HBV) infection, a universal HBV vaccination program for infants was launched in Taiwan in 1984. The aim of this study was to investigate the role of B-cell and T-cell epitope variations of HBsAg and polymerase in HBV infection in vaccinated children. One hundred sixty-three sera from vaccinated children were enrolled randomly. HBV serum markers, including hepatitis...

BACKGROUND Hepatitis B virus (HBV) is a serious risk factor for several severe liver diseases such as cirrhosis and hepatocellular carcinoma. HBV, like other viruses, uses several mechanisms to escape from specific immune responses including the use of mutations in the genome which lead to epitope variations. There are several immune responses, including T helper cells, cytotoxic T lymphocytes,...

abstract background: naturally occurred hepatitis b virus (hbv) with surface mutations in a variety of chronic hepatitis b (chb) patients who have received no vaccine or hbig bearing substitutions in surface protein, have been reported. objectives: current knowledge concerning the prevalence of these naturally occurring surface antigen mutations among iranian carriers is limited. patients and m...

Recombinant adenoviruses, poxviruses, and plasmid DNA vaccines encoding different hepatitis B virus (HBV)/murine cytomegalovirus (MCMV) protein chimeras were used to immunize mice. Processing of the chimeras resulted in presentation of a protective Ld/CD8+ T-cell epitope of the immediate early 1 protein pp89 (IE1 pp89) of MCMV to the immune system. Different levels of immunogenicity were observ...