title: Protection of mice against the lethal effect of an intraperitoneal infection with Haemophilus (Actinobacillus) pleuropneumoniae after vaccination with capsular proteins.
abstract: Haemophilus (Actinobacillus) pleuropneumoniae Serotypes 5 and 7 capsular antigens (CA-1) were precipitated from culture supernatants with N-cetyl-N,N,N,-trimethylammonium bromide (Cetavlon). CA-1 contained a carbohydrate to protein ratio of 2:1 for Serotype 5 and 3:1 for Serotype 7. Glucosamine and uronic acid were detected in CA-1 from both serotypes suggesting that the capsule contained hyaluronic acid. All mice immunized intraperitoneally with CA-1 vaccine were protected from death when challenged with 10X the LD50 of the homologous but not the heterologous serotype. Oil adjuvants and the use of young (6 h) cultures were necessary for CA-1 vaccines to be protective. Deproteinization of CA-1 with chloroform and butanol followed by pronase treatment resulted in failure to protect mice from death. The protective capsular protein antigen in CA-1 vaccine may not originate from the outer membrane (OM) since repeated washing of the OM to elute the capsular protein antigen rendered the OM vaccine completely nonprotective for mice. Vaccines prepared from cell-wall lipopolysaccharide also were nonprotective for mice. Passive immunization of mice with anti-CA-1 antibody produced in rabbits to Serotype 5 was highly protective (P less than 0.01) for mice when challenged with 10X the LD50 of the homologous serotype.
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha 68105.
authors.forename: D K
authors.initials: DK
authors.lastname: Lenser
authors.forename: T L
authors.initials: TL
authors.lastname: McDonald
authors.forename: N G
authors.initials: NG
authors.lastname: Miller
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D006190:Haemophilus / Q000276:immunology; D006192:Haemophilus Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D007116:Immunization, Passive; D051379:Mice; D013552:Swine; D013553:Swine Diseases / Q000276:immunology; D014611:Vaccination / Q000662:veterinary
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins