scholarly journals Molecular Basis for the Interaction of the Hepatitis B Virus Core Antigen with the Surface Immunoglobulin Receptor on Naive B Cells

2001 ◽  
Vol 75 (14) ◽  
pp. 6367-6374 ◽  
Author(s):  
Una Lazdina ◽  
Tinghua Cao ◽  
Juris Steinbergs ◽  
Mats Alheim ◽  
Paul Pumpens ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
B Cells ◽  
Hepatitis B ◽  
Light Chain ◽  
Molecular Basis ◽  
Cell Surface Receptor ◽  
Core Antigen ◽  
Binding Motif ◽  
Linear Motif ◽  
B Virus

ABSTRACT The nucleocapsid of the hepatitis B virus (HBV) is composed of 180 to 240 copies of the HBV core (HBc) protein. HBc antigen (HBcAg) capsids are extremely immunogenic and can activate naive B cells by cross-linking their surface receptors. The molecular basis for the interaction between HBcAg and naive B cells is not known. The functionality of this activation was evidenced in that low concentrations of HBcAg, but not the nonparticulate homologue HBV envelope antigen (HBeAg), could prime naive B cells to produce anti-HBc in vitro with splenocytes from HBcAg- and HBeAg-specific T-cell receptor transgenic mice. The frequency of these HBcAg-binding B cells was estimated by both hybridoma techniques and flow cytometry (B7-2 induction and direct HBcAg binding) to be approximately 4 to 8% of the B cells in a naive spleen. Cloning and sequence analysis of the immunoglobulin heavy- and light-chain variable (VH and VL) domains of seven primary HBcAg-binding hybridomas revealed that six (86%) were related to the murine and human VH1 germ line gene families and one was related to the murine VH3 family. By using synthetic peptides spanning three VH1 sequences, one VH3 sequence, and one VLκV sequence, a linear motif in the framework region 1 (FR1)complementarity-determining region 1 (CDR1) junction of the VH1 sequence was identified that bound HBcAg. Interestingly, the HBcAg-binding motif was present in the VL domain of the HBcAg-binding VH3-encoded antibody. Finally, two monoclonal antibodies containing linear HBcAg-binding motifs blocked HBcAg presentation by purified naive B cells to purified HBcAg-primed CD4+ T cells. Thus, the ability of HBcAg to bind and activate a high frequency of naive B cells seems to be mediated through a linear motif present in the FR1-CDR1 junction of the heavy or light chain of the B-cell surface receptor.

scholarly journals HLA-A31- and HLA-Aw68-restricted cytotoxic T cell responses to a single hepatitis B virus nucleocapsid epitope during acute viral hepatitis.

1993 ◽  
Vol 177 (3) ◽  
pp. 751-762 ◽  
Author(s):  
G Missale ◽  
A Redeker ◽  
J Person ◽  
P Fowler ◽  
S Guilhot ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Viral Hepatitis ◽  
Acute Viral Hepatitis ◽  
Hbv Infection ◽  
Cytotoxic T Cell ◽  
Core Antigen ◽  
Binding Motif ◽  
Ctl Response ◽  
B Virus

We have recently developed the technology to identify and characterize the human histocompatibility leukocyte antigen (HLA) class I-restricted, CD8+ cytotoxic T lymphocyte (CTL) response to hepatitis B virus (HBV)-encoded antigens in patients with acute viral hepatitis. CTL are expanded in vitro by stimulation with HBV-derived synthetic peptides and selected by restimulation with a panel of HLA-matched stable transfectants that express the corresponding HBV protein. We have recently reported the existence of an HLA-A2-restricted, CD8+ CTL response to an epitope located between residues 18 and 27 of the HBV nucleocapsid core antigen (HBcAg). We now report the discovery of a CTL epitope located between HBcAg residues 141 and 151 that completely overlaps a critical domain in the viral nucleocapsid protein that is essential for its nuclear localization and genome packaging functions as well as processing of the precore protein. The CTL response to this epitope is dually restricted by the HLA-A31 and HLA-Aw68 alleles, which, unexpectedly, appear to use a common binding motif based on the results of alanine substitution and competition analysis, and the binding properties of these two alleles predicted from their known primary sequence, and from the three-dimensional structure of HLA-Aw68. We have also demonstrated that the HBV-specific CTL response to this epitope is polyclonal during acute viral hepatitis, since these two restriction elements can present the HBcAg 141-151 epitope to independent CTL clones derived from a single patient; and that the CTL response is multispecific, since HLA-A2-restricted and HLA-Aw68-restricted CTL responses to HBcAg 18-27 and HBcAg 141-151, respectively, have been identified to coexist in another patient. The foregoing argue against the emergence of CTL escape mutants as a significant problem during HBV infection, especially at this locus, where mutations might be incompatible with viral replication. Finally, our data suggest an association between the HBV-specific CTL response and viral clearance, and they have implications for the design of immunotherapeutic strategies to terminate HBV infection in chronically infected patients.

scholarly journals Epitope–Paratope Interaction of a Neutralizing Human Anti-Hepatitis B Virus PreS1 Antibody That Recognizes the Receptor-Binding Motif

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 754
Author(s):  
Jisu Hong ◽  
Youngjin Choi ◽  
Yoonjoo Choi ◽  
Jiwoo Lee ◽  
Hyo Jeong Hong
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Receptor Binding ◽  
Neutralizing Antibody ◽  
Hbv Infection ◽  
Binding Motif ◽  
Alanine Scanning Mutagenesis ◽  
B Virus ◽  
Complementarity Determining Regions

Hepatitis B virus (HBV) is a global health burden that causes acute and chronic hepatitis. To develop an HBV-neutralizing antibody that effectively prevents HBV infection, we previously generated a human anti-preS1 monoclonal antibody (1A8) that binds to genotypes A–D and validated its HBV-neutralizing activity in vitro. In the present study, we aimed to determine the fine epitope and paratope of 1A8 to understand the mechanism of HBV neutralization. We performed alanine-scanning mutagenesis on the preS1 (aa 19–34, genotype C) and the heavy (HCDR) and light (LCDR) chain complementarity-determining regions. The 1A8 recognized the three residues (Leu22, Gly23, and Phe25) within the highly conserved receptor-binding motif (NPLGFFP) of the preS1, while four CDR residues of 1A8 were critical in antigen binding. Structural analysis of the epitope–paratope interaction by molecular modeling revealed that Leu100 in the HCDR3, Ala50 in the HCDR2, and Tyr96 in the LCDR3 closely interacted with Leu22, Gly23, and Phe25 of the preS1. Additionally, we found that 1A8 also binds to the receptor-binding motif (NPLGFLP) of infrequently occurring HBV. The results suggest that 1A8 may broadly and effectively block HBV entry and thus have potential as a promising candidate for the prevention and treatment of HBV infection.

scholarly journals Coverage with Timely Administered Vaccination against Hepatitis B Virus and Its Influence on the Prevalence of HBV Infection in the Regions of Different Endemicity

Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 82
Author(s):  
Karen K. Kyuregyan ◽  
Vera S. Kichatova ◽  
Olga V. Isaeva ◽  
Ilya A. Potemkin ◽  
Elena Yu. Malinnikova ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Birth Cohort ◽  
Herd Immunity ◽  
Hepatitis B Vaccination ◽  
Core Antigen ◽  
Infection Prevalence ◽  
Belgorod Oblast ◽  
Medical Specialties ◽  
B Virus

Universal hepatitis B vaccination of newborns was implemented in Russia starting from 1998. From 1998 to 2019, the incidence of acute hepatitis B reduced from 43.8 to 0.57 cases per 100,000 population. Here, we assessed the timely coverage of newborns with the birth dose (HepB-BD), second dose (HepB-2nd), and three vaccine doses (HepB3) in two remote regions of Russia with low (Belgorod Oblast) and high (Yakutia) levels of hepatitis B virus (HBV) endemicity. Vaccination data were obtained from the medical records of 1000 children in Yakutia and 2182 children in Belgorod Oblast. Sera of healthy volunteers from Belgorod Oblast (n = 1754) and Yakutia (n = 1072) across all age groups were tested for serological markers of HBV to assess the infection prevalence and herd immunity. Average HepB-BD coverage was 99.2% in Yakutia and 89.4% in Belgorod Oblast (p < 0.0001) and in both regions varied significantly, from 66% to 100%, between medical centers. The principal reason for the absence of HepB-BD was parent refusal, which accounted for 63.5% of cases of non-vaccination (83/123). While timely HepB-2nd coverage was only 55.4%–64.7%: HepB3 coverage by the age of one year exceeded 90% in both study regions. HBV surface antigen (HBsAg) prevalence in the 1998–2019 birth cohort was 0.2% (95% CI: 0.01–1.3%) in Belgorod Oblast and 3.2% (95% CI: 1.9–5.2%) in Yakutia. The proportion of persons testing negative for both antibodies to HBsAg (anti-HBs) and antibodies to HBV core antigen (anti-HBc) in the 1998–2019 birth cohort was 26.2% (125/481) in Belgorod Oblast and 32.3% (162/501) in Yakutia. We also assessed the knowledge of and attitude towards vaccination among 782 students and teachers of both medical and non-medical specialties from Belgorod State University. Only 60% of medical students knew that hepatitis B is a vaccine-preventable disease. Both medical and nonmedical students, 37.8% and 31.3%, respectively, expressed concerns about safety and actual necessity of vaccination. These data indicate the need to introduce a vaccine delivery audit system, improve medical education with respect to vaccination strategies and policies, and reinforce public knowledge on the benefits of vaccination.

scholarly journals Efficient Production of Chimeric Hepatitis B Virus-Like Particles Bearing an Epitope of Hepatitis E Virus Capsid by Transient Expression in Nicotiana benthamiana

Life ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 64
Author(s):  
Gergana Zahmanova ◽  
Milena Mazalovska ◽  
Katerina Takova ◽  
Valentina Toneva ◽  
Ivan Minkov ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Nicotiana Benthamiana ◽  
Hepatitis E Virus ◽  
Chimeric Protein ◽  
Hepatitis E ◽  
Core Antigen ◽  
Efficient Production ◽  
Virus Like Particles ◽  
B Virus

The core antigen of hepatitis B virus (HBcAg) is capable of self-assembly into virus-like particles (VLPs) when expressed in a number of heterologous systems. Such VLPs are potential carriers of foreign antigenic sequences for vaccine design. In this study, we evaluated the production of chimeric HBcAg VLPs presenting a foreign epitope on their surface, the 551–607 amino acids (aa) immunological epitope of the ORF2 capsid protein of hepatitis E virus. A chimeric construct was made by the insertion of 56 aa into the immunodominant loop of the HBcAg. The sequences encoding the chimera were inserted into the pEAQ-HT vector and infiltrated into Nicotiana benthamiana leaves. The plant-expressed chimeric HBcHEV ORF2 551–607 protein was recognized by an anti-HBcAg mAb and anti-HEV IgG positive swine serum. Electron microscopy showed that plant-produced chimeric protein spontaneously assembled into “knobbly” ~34 nm diameter VLPs. This study shows that HBcAg is a promising carrier platform for the neutralizing epitopes of hepatitis E virus (HEV) and the chimeric HBcAg/HEV VLPs could be a candidate for a bivalent vaccine.

Expression of hepatitis B viral core region in mammalian cells

1986 ◽  
Vol 6 (5) ◽  
pp. 1393-1400
Author(s):  
M J Roossinck ◽  
S Jameel ◽  
S H Loukin ◽  
A Siddiqui
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Mammalian Cells ◽  
Expression System ◽  
Core Region ◽  
Core Antigen ◽  
Northern Blot Hybridization ◽  
The Core ◽  
B Virus ◽  
Nuclease Mapping

We studied the expression of the core region of the hepatitis B virus genome in mammalian cells with recombinant plasmid vectors. Stably transformed rat fibroblast cell lines were established by transfection with vectors containing subgenomic and genome-length hepatitis B virus DNA, followed by G418 selection. The RNA transcripts directed by the core region were characterized by Northern blot hybridization and S1 nuclease mapping. Using the chloramphenicol acetyltransferase gene expression system, the promoter activity located upstream of the core open reading frame was confirmed. The synthesis of core and e polypeptides was studied with a commercial radioimmunoassay. These studies show that partial deletion of the precore sequences abolished secretion of the e antigen, but there was pronounced synthesis of the core antigen in transfected cells.

Immunological Responsiveness of Pekin Ducks to Core Antigen of Duck Hepatitis B Virus

Intervirology ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 316-324
Author(s):  
Klaus-Hinrich Heermann ◽  
Dagmar Wagenseil ◽  
Stephan Lottmann ◽  
Wolfram H. Gerlich ◽  
Reiner Thomssen
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Antigen ◽  
Duck Hepatitis B Virus ◽  
Pekin Ducks ◽  
Duck Hepatitis ◽  
B Virus
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