title: Identification of immunogenic and virulence-associated Campylobacter jejuni proteins.
abstract: With the aim of identifying proteins important for host interaction and virulence, we have screened an expression library of NCTC 11168 Campylobacter jejuni genes for highly immunogenic proteins. A commercial C. jejuni open reading frame (ORF) library consisting of more than 1,600 genes was transformed into the Escherichia coli expression strain BL21(DE3), resulting in 2,304 clones. This library was subsequently screened for immunogenic proteins using antibodies raised in rabbit against a clinical isolate of C. jejuni; this resulted in 52 highly reactive clones representing 25 different genes after sequencing. Selected candidate genes were inactivated in C. jejuni NCTC 11168, and the virulence was examined using INT 407 epithelial cell line and motility, biofilm, autoagglutination, and serum resistance assays. These investigations revealed C. jejuni antigen 0034c (Cj0034c) to be a novel virulence factor and support the usefulness of the method. Further, several antigens were tested as vaccine candidates in two mouse models, in which Cj0034c, Cj0404, and Cj0525c resulted in a reduction of invasion in spleen and liver after challenge.
authors.affiliation: Department of Microbiological Surveillance and Researcha and Unit for Electron Microscopy, of Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Lene N
authors.initials: LN
authors.lastname: Nielsen
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Luijkx
authors.forename: Christina S
authors.initials: CS
authors.lastname: Vegge
authors.forename: Christina Kofoed
authors.initials: CK
authors.lastname: Johnsen
authors.forename: Piet
authors.initials: P
authors.lastname: Nuijten
authors.forename: Brendan W
authors.initials: BW
authors.lastname: Wren
authors.forename: Hanne
authors.initials: H
authors.lastname: Ingmer
authors.forename: Karen A
authors.initials: KA
authors.lastname: Krogfelt
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001428:Bacterial Vaccines / Q000276:immunology; D001483:Base Sequence; D002169:Campylobacter Infections / Q000235:genetics / Q000276:immunology; D016123:Campylobacter jejuni / Q000235:genetics* / Q000276:immunology* / Q000472:pathogenicity; D002460:Cell Line; D004926:Escherichia coli / Q000235:genetics; D055786:Gene Knockout Techniques; D015723:Gene Library; D005798:Genes, Bacterial; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D017422:Sequence Analysis, DNA; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D037521:Virulence Factors