title: Development and characterisation of recombinant hepatitis delta virus-like particles.
abstract: Injection of particulate hepatitis B virus surface antigen (HBsAg) in mice leads to the induction of a HBsAg-specific class-I-restricted cytotoxic T lymphocyte (CTL) response. It is proposed that any protein internal to HBsAg will also be able to elicit a specific CTL response. In this study, several carboxy-terminal truncations of hepatitis C virus (HCV) core protein were fused to varying lengths of amino-terminal truncated large hepatitis delta antigen (L-HDAg). These constructs were analysed for their ability to be expressed and the particles secreted in the presence of HBsAg after transfection into HuH-7 cells. The secretion efficiency of the various HCV core-HDAg chimeric proteins was generally poor. Constructs containing full length HDAg appeared to be more stable than truncated versions and the length of the inserted protein was restricted to around 40 amino acids. Thus, the use of L-HDAg as a chimera to package foreign proteins is limited. Consequently, a polyepitope (polytope) containing a B-cell epitope from human papillomavirus (HPV 16) and multiple T-cell epitopes from the HCV polyprotein was used to create the construct, L-HDAg-polyB. This chimeric protein was shown to be reliant on the co-expression of HBsAg for secretion into the cell culture fluid and was secreted more efficiently than the previous HCV core-HDAg constructs. These L-HDAg-polyB virus-like particles (VLPs) had a buoyant density of approximately 1.2 g/cm3 in caesium chloride and approximately 1.15 g/cm3 in sucrose. The VLPs were also immunoprecipitated using an anti-HBs but not an anti-HD antibody. Thus, these recombinant VLPs have similar biophysical properties to L-HDAg VLPs.
authors.affiliation: Clinical Medical Virology Centre, The University of Queensland, St Lucia, Australia.
authors.forename: S M
authors.initials: SM
authors.lastname: Ward
authors.forename: T B
authors.initials: TB
authors.lastname: Macnaughto
authors.forename: E J
authors.initials: EJ
authors.lastname: Gowans
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002499:Centrifugation, Density Gradient; D004279:DNA, Viral; D018985:Epitopes, B-Lymphocyte / Q000235:genetics; D018984:Epitopes, T-Lymphocyte / Q000235:genetics; D015870:Gene Expression; D005822:Genetic Vectors / Q000235:genetics*; D018963:Hepatitis Antigens / Q000235:genetics*; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D003698:Hepatitis Delta Virus / Q000235:genetics* / Q000502:physiology; D035923:Hepatitis delta Antigens; D006801:Humans; D008969:Molecular Sequence Data; D009856:Oncogene Proteins, Viral / Q000235:genetics*; D027383:Papillomaviridae / Q000235:genetics*; D050725:Papillomavirus E7 Proteins; D011233:Precipitin Tests; D011995:Recombination, Genetic; D014407:Tumor Cells, Cultured; D014758:Viral Core Proteins / Q000235:genetics*; D017361:Viral Nonstructural Proteins / Q000235:genetics*; D014771:Virion; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; D012324:RNA-Dependent RNA Polymerase
chemical_list: D004279:DNA, Viral; D018985:Epitopes, B-Lymphocyte; D018984:Epitopes, T-Lymphocyte; D018963:Hepatitis Antigens; D006514:Hepatitis B Surface Antigens; D035923:Hepatitis delta Antigens; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D014758:Viral Core Proteins; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C442244:hepatitis delta virus large antigen; C069130:nucleocapsid protein, Hepatitis C virus; C059731:oncogene protein E7, Human papillomavirus type 16; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase