title: Effect of variation in the common "a" determinant on the antigenicity of hepatitis B surface antigen.
abstract: Antibody to the common "a" determinant of hepatitis B surface antigen (HBsAg) protects against infection with hepatitis B virus. A number of variant surface antigens with amino acid substitutions within the "a" determinant have been described in patients around the world. Both wild type and variant HBsAgs were expressed in the yeast Pichia pastoris and the antigens were semi-purified and quantitated. The effect on antigenicity of these changes was investigated in a quantitative fashion using four monoclonal antibodies known to bind to different epitopes within the common "a" determinant. The results suggest that amino acid substitution of T131I, K141E and G145R and insertion of 3 amino acids between residues 123 and 124 markedly affect the antigenic structure of HBsAg. These substitutions and insertions in the viral envelope may lead to evasion of the virus neutralizing antibody response and also to reduce efficiency of detection by immunoassays used for diagnosis and blood-bank screening.
authors.affiliation: Hepatology Section, Department of Medicine A, Imperial College School of Medicine, London, England.
authors.forename: S
authors.initials: S
authors.lastname: Seddigh-Tonekaboni
authors.forename: J A
authors.initials: JA
authors.lastname: Waters
authors.forename: S
authors.initials: S
authors.lastname: Jeffers
authors.forename: R
authors.initials: R
authors.lastname: Gehrke
authors.forename: B
authors.initials: B
authors.lastname: Ofenloch
authors.forename: A
authors.initials: A
authors.lastname: Horsch
authors.forename: G
authors.initials: G
authors.lastname: Hess
authors.forename: H C
authors.initials: HC
authors.lastname: Thomas
authors.forename: P
authors.initials: P
authors.lastname: Karayiannis
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000940:Antigenic Variation; D002648:Child; D002675:Child, Preschool; D003001:Cloning, Molecular; D018604:Epitope Mapping; D000939:Epitopes; D005822:Genetic Vectors / Q000235:genetics; D006514:Hepatitis B Surface Antigens / Q000096:biosynthesis / Q000235:genetics*; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization; D015336:Molecular Probe Techniques; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010843:Pichia / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis; D016622:Silver Staining
chemical_list: D000939:Epitopes; D006514:Hepatitis B Surface Antigens; D011994:Recombinant Proteins