Search results for "Hepatitis B virus PRE beta"

The significance of the pre-S region of the hepatitis B virus

1986

Stop codon insertion restores the particle formation ability of hepatitis B virus core-hantavirus nucleocapsid protein fusions.

2003

In recent years, epitopes of various origin have been inserted into the core protein of hepatitis B virus (HBc), allowing the formation of chimeric HBc particles. Although the C-terminus of a C-terminally truncated HBc (HBcΔ) tolerates the insertion of extended foreign sequences, the insertion capacity is still a limiting factor for the construction of multivalent vaccines. Previously, we described a new system to generate HBcΔ mosaic particles based on a read-through mechanism in an <i>Escherichia coli</i> suppressor strain [J Gen Virol 1997;78:2049–2053]. Those mosaic particles allowed the insertion of a 114-amino acid (aa)-long segment of a Puumala hantavirus (PUUV) nucleocap…

Hepatic expression patterns of the large and middle hepatitis B virus surface proteins in viremic and nonviremic chronic hepatitis B.

1990

The envelope of hepatitis B virus consists of large, middle, and small hepatitis B surface proteins. Recent data from in vitro studies suggest that intracellular expression and distribution of the three polypeptides may be variable. These observations in artificial expression systems prompted this analysis of the occurrence and distribution of the three hepatitis B surface proteins in the liver tissue of substantial viremic (hepatitis B virus DNA- and hepatitis B e antigen-positive) and low-viremic or nonviremic (hepatitis B virus DNA-negative, anti-hepatitis B e antigen-positive) carriers by specific monoclonal antibodies against large, middle, and small proteins. Patients with an active f…

Interaction of wild-type and naturally occurring deleted variants of hepatitis B virus core polypeptides leads to formation of mosaic particles

2000

AbstractThe simultaneous presence of hepatitis B virus (HBV) genomes carrying wild-type (wt) and in-frame deleted variants of the HBV core gene has been identified as a typical feature of HBV-infected renal transplant patients with severe liver disease. To investigate possible interactions of wt and deleted core polypeptides a two-vector Escherichia coli expression system ensuring their concomitant synthesis has been developed. Co-expression of wt and a mutant core lacking 17 amino acid residues (77–93) within the immunodominant region led to the formation of mosaic particles, whereas the mutant alone was incapable of self-assembly.

Hepatitis B and C virus variants in long-term immunosuppressed renal transplant patients in Latvia.

2004

The incidence of genome variants of hepatitis B and hepatitis C viruses among 38 long-term (2–15 years) immunosuppressed patients after renal transplantation and 10 patients undergoing dialysis was investigated. Twelve patients had only HBV infection, 9 had only HCV infection and 14 were co-infected. Regions corresponding to the HBV X/EnII/BCP, preC/C, preS/S and to the HCV core were sequenced for molecular characterization of the HBV and HCV genomes. Fifty-seven percent of HBV DNA isolates belonged to genotype D and 42% to genotype A, whereas 77% of HCV RNA isolates belonged to genotype 1b and only 17% to genotype 3a. One sample (6%) was of genotype 2c. Detailed analysis of the above-menti…

Possible role of human interleukin-6 and soluble interleukin-6 receptor in hepatitis B virus infection

2001

Human interleukin-6 has been shown to promote hepatitis B virus (HBV) infection. However, it is not clear whether this influence is the result of a direct interaction between interleukin-6 (IL-6) and the HBV envelope proteins or of a rather indirect mechanism. A direct interaction of IL-6 and the preS region of the large envelope protein (L-protein) of HBV has been reported. In this study we assessed the binding of IL-6 and of the IL-6 receptor subunits to the preS region of the L-protein of HBV. Binding of IL-6 and IL-6 receptor subunits sIL-6R and gp130 to preS was assessed by immunoprecipitation with recombinant preS proteins. In patient sera IL-6 and sIL-6R concentrations were analysed …

Virus replication and virion export in X-deficient hepatitis B virus transgenic mice

2002

The function of the X protein (pX) in the replication cycle of mammalian hepadnaviruses is enigmatic. Using tissue culture experiments it has been shown that the X gene product is not central to hepatitis B virus (HBV) replication and virion export. However, at present it is still unclear whether this also applies to the in vivo situation. Using a terminally redundant X-deficient HBV DNA construct, transgenic mice were established that exhibited high-level expression of the viral core protein in liver and kidneys. Importantly, replicative DNA intermediates and mature viral genomes could be detected in the liver and serum of these mice, respectively. These findings indicate that, in the in v…

Use of the polymerase chain reaction to demonstrate hepatitis B virus DNA in serum of children with chronic hepatitis B.

1992

The polymerase chain reaction was used to investigate the presence of hepatitis B virus DNA in sera of 61 children with chronic hepatitis B and negative results on dot biot hybridization tests. Our results demonstrate that most chronic carriers of hepatitis B surface antigen in childhood have hepatitis B virus DNA detectable by polymerase chain reaction in their serum and must be considered infectious.

Detection of hepatitis B virus DNA by polymerase chain reaction in serum and liver of children with chronic hepatitis B negative for hepatitis B viru…

1992

Hepatitis B virus (HBV) DNA was detected by polymerase chain reaction in the serum of 87 and liver tissue of 40 children with chronic hepatitis B, negative for HBV DNA by dot blot and Southern blot hybridization, respectively. In sera HBV DNA could be detected in 73 hepatitis B surface antigen carriers; 14 were hepatitis B e antigen (HBeAg), 56 were anti-HBe-seropositive and 3 had neither HBeAg nor positive anti-HBe. In 14 anti-HBe-positive patients no HBV DNA could be found. Viral sequences in liver tissue were present in 33 specimens; 20 were HBeAg and 13 were anti-HBe-seropositive. All of the 7 negative children had anti-HBe. Our results confirm polymerase chain reaction to be a more sen…

Posttranslational N-glycosylation of the hepatitis B virus large envelope protein

2007

Abstract Background The addition of N-linked glycans to proteins is normally a cotranslational process that occurs during translocation of the nascent protein to the endoplasmic reticulum. Here, we report on an exception to this rule occurring on the hepatitis B virus (HBV) large L envelope protein that is a subject to co-plus posttranslational N-glycosylation. Results By using an improved detection system, we identified so far unrecognized, novel isoforms of L. Based on mutational analyses, the use of N-glycosylation inhibitors, and pulse-chase studies, we showed that these isoforms are due to posttranslational N-glycan addition to the asparagines 4 and 112 within the preS domain of L. Whi…