title: Characterization of a 39kDa capsular protein of avian Pasteurella multocida using monoclonal antibodies.
abstract: The role of a 39kDa protein of avian Pasteurella multocida in pathogenesis of fowl cholera was investigated using monoclonal antibodies (Mabs). Mabs were prepared by immunization of BALB/c mice with a crude capsular extract (CCE) of P. multocida strain P-1059 (serovar A:3). Totally eight hybridomas producing Mab were obtained. Immunoblot analysis of the hybridomas revealed that all the Mabs recognized a 39kDa protein of CCE. Treatment of CCE antigen with proteinase K or periodic acid indicated that the epitope recognized was proteinaceous. The Mabs reacted with a major 39kDa protein of CCE from encapsulated strains but not with any protein of non-capsulated strains indicating that a direct correlation between encapsulation and the 39kDa protein. Immunoelectron microscopy on strain P-1059 and the non-capsulated derivative P-1059B (serovar -:3) reacting with the Mabs and gold-labeled anti-mouse IgG indicated that the protein is associated with the capsule. The Mabs significantly inhibited the adherence of encapsulated P. multocida strains to chicken embryo fibroblast cells, but only slightly that of non-capsulated strains. Mice passively immunized with the Mabs were protected from lethal challenge with virulent strains P-1059 and X-73 (serovar A:1). Thus the capsular 39kDa protein was determined to be an adherence factor and a cross-protective antigen of avian P. multocida type A strains.
authors.affiliation: Department of Veterinary Microbiology, Faculty of Veterinary Medicine, Nippon Veterinary and Animal Science University, Musashino, Tokyo 180-8602, Japan.
authors.forename: Hussam Al-haj
authors.initials: HA
authors.lastname: Ali
authors.forename: Takuo
authors.initials: T
authors.lastname: Sawada
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hatakeyama
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Ohtsuki
authors.forename: Osamu
authors.initials: O
authors.lastname: Itoh
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology; D001422:Bacterial Adhesion / Q000276:immunology; D016667:Bacterial Capsules / Q000276:immunology*; D001715:Bird Diseases / Q000382:microbiology*; D001717:Birds; D015153:Blotting, Western / Q000662:veterinary; D002642:Chick Embryo; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D000939:Epitopes; D005260:Female; D005347:Fibroblasts; D051379:Mice; D008807:Mice, Inbred BALB C; D016253:Microscopy, Immunoelectron / Q000662:veterinary; D010326:Pasteurella Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D016979:Pasteurella multocida / Q000276:immunology* / Q000472:pathogenicity / Q000648:ultrastructure; D014774:Virulence
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D000939:Epitopes