title: Expression of an inaccessible P1.7 subtype epitope on meningococcal class 1 proteins.
abstract: Dot-blot analysis of whole-cell suspensions of meningococci showed that 81% of B:15:P1.16 strains from patients reacted with a monoclonal antibody (MAb) against subtype P1.7. The remaining strains, which did not react on dot-blots or in ELISA, demonstrated the P1.7 subtype epitope on immunoblots after denaturation of the cells with sodium dodecyl sulphate. The monomeric class 1 proteins of the two P1.16 subtype variants had slightly different mol. wts, but bound the P1.7 antibody equally well. These results were explained by a deletion of three codons in the gene encoding the first variable region of the P1.16 class 1 protein. The deletion accounted for the non-exposure of the P1.7 epitope on native cells. Other patient strains, with subtypes P1.3, P1.9 or without any known subtype, also showed a binding site for the P1.7 MAb, which became available only after denaturation. Demonstration of inaccessible epitopes may have consequences for subtype designations and vaccine development.
authors.affiliation: National Institute of Public Health, Oslo, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Wedege
authors.forename: R
authors.initials: R
authors.lastname: Dalseg
authors.forename: D A
authors.initials: DA
authors.lastname: Caugant
authors.forename: J T
authors.initials: JT
authors.lastname: Poolman
authors.forename: L O
authors.initials: LO
authors.lastname: Frøholm
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000032:analysis* / Q000737:chemistry; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D004269:DNA, Bacterial / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis / Q000737:chemistry; D015964:Gene Expression Regulation, Bacterial; D005838:Genotype; D006801:Humans; D015151:Immunoblotting; D008589:Meningococcal Infections / Q000382:microbiology*; D008969:Molecular Sequence Data; D009345:Neisseria meningitidis / Q000145:classification / Q000276:immunology*; D016133:Polymerase Chain Reaction; D018272:Porins; D012703:Serotyping
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; D000939:Epitopes; D018272:Porins; C057699:porin protein, Neisseria