title: Epitope mapping of pneumococcal surface protein A of strain Rx1 using monoclonal antibodies and molecular structure modelling.
abstract: Pneumococcal surface protein A (PspA) is an antigenic variable vaccine candidate of Streptococcus pneumoniae. Epitope similarities between PspA from the American vaccine candidate strain Rx1 and Norwegian clinical isolates were studied using PspA specific monoclonal antibodies (mAbs) made against clinical Norwegian strains. Using recombinant PspA/Rx1 fragments and immunoblotting the epitopes for mAbs were mapped to two regions of amino acids, 1-67 and 67-236. The discovered epitopes were visualized by modelling of the PspA:Fab part of mAb in three dimensions. Flow cytometric analysis showed that the epitopes for majority of mAbs were accessible for antibody binding on live pneumococci. Also, the epitopes for majority of the mAbs are widely expressed among clinical Norwegian isolates.
authors.affiliation: Department of Airborne Infections, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, 0403 Oslo, Norway. jan.kolberg@fhi.no
authors.forename: Jan
authors.initials: J
authors.lastname: Kolberg
authors.forename: Audun
authors.initials: A
authors.lastname: Aase
authors.forename: Gunnhild
authors.initials: G
authors.lastname: Rødal
authors.forename: James E
authors.initials: JE
authors.lastname: Littlejohn
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Jedrzejas
mesh_terms: D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D005434:Flow Cytometry; D006801:Humans; D008958:Models, Molecular; D011008:Pneumococcal Infections / Q000382:microbiology / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000276:immunology*; D011994:Recombinant Proteins; D013296:Streptococcus pneumoniae / Q000737:chemistry / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D022242:Pneumococcal Vaccines; D011994:Recombinant Proteins; C051592:pneumococcal surface protein A