title: Polyhistidine-tagged hepatitis B core particles as carriers of HIV-1/gp120 epitopes of different HIV-1 subtypes.
abstract: The hepatitis B core antigen is a widely accepted carrier particle to enhance the immunogenicity of foreign epitopes. From electron cryomicroscopy, the immunodominant region between amino acid positions 79 to 81 is known to protrude from the surface of the shells. It can be replaced by heterologous sequences without interfering with the particle-forming capacity in many cases. Here we have introduced various V3 sequences of the envelope protein of different subtypes (A, B, O) of HIV-1/gp120 in order to enhance their immunogenicity and broaden the immune response against the virus. To improve purification efficiency and solubility of the E. coli-expressed hybrids, six histidine residues were fused to amino acid 156. An adjustable purification scheme was utilised including denaturation, Ni(2+)-NTA affinity chromatography and particle renaturation under high salt conditions, resulting in highly pure antigen preparations. The hybrids reacted specifically with sera of HIV-1-infected patients. They further induced an autologous, subtype-specific anti-HIV-1 antibody response superior to that of Keyhole limpet-haemocyanine-coupled peptides.
authors.affiliation: Max-von-Pettenkofer-Institut, Lehrstuhl Virologie, Genzentrum, München Germany.
authors.forename: H
authors.initials: H
authors.lastname: Wizemann
authors.forename: F
authors.initials: F
authors.lastname: Weiland
authors.forename: E
authors.initials: E
authors.lastname: Pfaff
authors.forename: A
authors.initials: A
authors.lastname: von Brunn
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D004926:Escherichia coli; D015870:Gene Expression; D015699:HIV Envelope Protein gp120 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology; D015497:HIV-1 / Q000145:classification* / Q000276:immunology; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006639:Histidine; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000096:biosynthesis / Q000235:genetics; D013329:Structure-Activity Relationship
chemical_list: D000914:Antibodies, Viral; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D006512:Hepatitis B Core Antigens; D016056:Immunodominant Epitopes; D010446:Peptide Fragments; D006639:Histidine