background hypervariability of hcv proteins is an important obstacle to design an efficient vaccine for hcv infection. multi-epitope vaccines containing conserved epitopes of the virus could be a promising approach for protection against hcv. objectives cellular and humoral immune responses against multi-epitope dna and peptide vaccines were evaluated in balb/c mice. materials and methods in th...

background: hepatitis b virus (hbv) gene and protein variations are frequently been seen in chronic patients. the aims of study were to determine the genotypes as well as the patterns of variations distribution in chronically-infected patients from the central part of iran. methods: the surface gene was amplified, sequenced and subsequently aligned using international and national iranian datab...

objective(s) the aim of this study was to characterize the hepatitis b virus surface protein genotypes and sequence variations among hepatitis b virus surface antigen (hbsag) positive chronic patients in hormozgan province, south of iran. materials and methods a total of 8 patients enrolled in this study. the surface gene was amplified and directly sequenced. genotypes and nucleotide/amino acid...

In view of the high antigenic variability of human immunodeficiency virus type 1 (HIV-1), a vaccine against AIDS must induce an immune response to epitopes as invariable as possible among the various virus strains and clones. Previously the highly conserved six amino acid sequence Glu-Leu-Asp-Lys-Trp-Ala (ELDKWA) from gp41, defining the epitope of the human MAb 2F5, was shown to elicit HIV-1-ne...

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...

HBs protein is encoded by the pre-S and S genome, and the detection of HBs antigen (HBsAg) in sera is an initial step for the diagnosis of hepatitis B virus (HBV) infection. The “a” determinant region (amino acid residues 124–147) is the main epitope for inducing a protective immune response. Mutations in the “a” determinant region, known as escape mutants, affect antigenicity and hinder attemp...

Neutralizing monoclonal antibody (BX-182) directed against the d determinant of hepatitis B virus (HBV) surface antigen protected chimpanzees from infection by HBV subtype adw but not by subtype ayw, as demonstrated by intravenously inoculating a mixture of the antibody with the respective subtype of the virus. To elucidate the mechanism underlying the subtype-specific protection, a combinatori...

Viruses employ various means to evade immune detection. Reduction of CD8(+) T cell epitopes is one of the common strategies used for this purpose. Hepatitis B virus (HBV), a member of the Hepadnaviridae family, has four open reading frames, with about 50% overlap between the genes they encode. We computed the CD8(+) T cell epitope density within HBV proteins and the mutations within the epitope...

The present study sought to evaluate the structure of HBV quasispecies in Lamivudine (LMV)-failed chronic hepatitis B (CHB) patients and its impact in defining the subsequent virological responses to Tenofovir (TDF)-based rescue-therapy. By analyzing HBV clones encompassing reverse transcriptase (RT) and surface (S) region from LMV-failed and treatment-naïve CHB patients, we identified 5 classi...