title: Role of plasmid-encoded antigens of Yersinia enterocolitica in humoral immunity against secondary Y. enterocolitica infection in mice.
abstract: In the present study the role of Yersinia enterocolitica antigens in humoral immunity against secondary Y. enterocolitica infection has been investigated. For this purpose, BALB/c mice, 4 weeks after immunization by primary infection with a sublethal dose of various Y. enterocolitica strains and mutant strains, were challenged with a lethal dose of highly virulent Y. enterocolitica strains of serotype O:8. As evident from the survival rate and protection against bacterial growth in the spleens of mice, only immunization with wild-type or attenuated strains harbouring an intact virulence plasmid mediated protection against a lethal challenge. Protection by immunization with plasmid-harbouring strains correlated with persistence of the bacteria in spleens for at least 7 days after immunization and high serum titres of Yersinia-specific antibodies directed against both chromosomal and plasmid-encoded determinants. Furthermore, the adoptive transfer of the purified IgG fraction of a rabbit serum specific for the adhesin YadA encoded by virulence plasmid pO8 from Y. enterocolitica O:8 mediated protection against a lethal challenge with the serotype O:8 strain harbouring the virulence plasmid pO8 but did not mediate protection when this strain harboured the virulence plasmid pO9 from serotype O:9. In summary, the results demonstrate that in our experimental mouse infection model: (i) the presence of the intact virulence plasmid in an immunizing Y. enterocolitica strain is essential for induction of protection against a lethal challenge with highly virulent Y. enterocolitica and (ii) that antibodies against plasmid-encoded determinants of Y. enterocolitica, especially YadA, are of major importance for achievement of protective immunity in mice.
authors.affiliation: Institute for Hygiene and Microbiology, University of Würzburg, FRG.
authors.forename: U
authors.initials: U
authors.lastname: Vogel
authors.forename: I B
authors.initials: IB
authors.lastname: Autenrieth
authors.forename: R
authors.initials: R
authors.lastname: Berner
authors.forename: J
authors.initials: J
authors.lastname: Heesemann
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000917:Antibody Formation; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000276:immunology*; D005260:Female; D007110:Immunity, Active; D007114:Immunization; D007116:Immunization, Passive; D007074:Immunoglobulin G / Q000097:blood; D007928:Lethal Dose 50; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000382:microbiology; D014774:Virulence; D015009:Yersinia Infections / Q000276:immunology*; D015008:Yersinia enterocolitica / Q000276:immunology* / Q000472:pathogenicity
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007074:Immunoglobulin G