title: Profiling antibody responses to infections by Chlamydia abortus enables identification of potential virulence factors and candidates for serodiagnosis.
abstract: Enzootic abortion of ewes (EAE) due to infection with the obligate intracellular pathogen Chlamydia (C.) abortus is an important zoonosis leading to considerable economic loss to agriculture worldwide. The pathogen can be transmitted to humans and may lead to serious infection in pregnant women. Knowledge about epidemiology, clinical course and transmission to humans is hampered by the lack of reliable diagnostic tools. Immunoreactive proteins, which are expressed in infected animals and humans, may serve as novel candidates for diagnostic marker proteins and represent putative virulence factors. In order to broaden the spectrum of immunogenic C. abortus proteins we applied 2D immunoblot analysis and screening of an expression library using human and animal sera. We have identified 48 immunoreactive proteins representing potential diagnostic markers and also putative virulence factors, such as CAB080 (homologue of the "macrophage infectivity potentiator", MIP), CAB167 (homologue of the "translocated actin recruitment protein", TARP), CAB712 (homologue of the "chlamydial protease-like activity factor", CPAF), CAB776 (homologue of the "Polymorphic membrane protein D", PmpD), and the "hypothetical proteins" CAB063, CAB408 and CAB821, which are predicted to be type III secreted. We selected two putative virulence factors for further characterization, i.e. CAB080 (cMIP) and CAB063, and studied their expression profiles at transcript and protein levels. Analysis of the subcellular localization of both proteins throughout the developmental cycle revealed CAB063 being the first C. abortus protein shown to be translocated to the host cell nucleus.
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Hospital, Ulm, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Forsbach-Birk
authors.forename: Corinna
authors.initials: C
authors.lastname: Foddis
authors.forename: Ulrike
authors.initials: U
authors.lastname: Simnacher
authors.forename: Max
authors.initials: M
authors.lastname: Wilkat
authors.forename: David
authors.initials: D
authors.lastname: Longbottom
authors.forename: Gernot
authors.initials: G
authors.lastname: Walder
authors.forename: Christiane
authors.initials: C
authors.lastname: Benesch
authors.forename: Martin
authors.initials: M
authors.lastname: Ganter
authors.forename: Konrad
authors.initials: K
authors.lastname: Sachse
authors.forename: Andreas
authors.initials: A
authors.lastname: Essig
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000917:Antibody Formation / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D045744:Cell Line, Tumor; D002689:Chlamydia / Q000276:immunology*; D002690:Chlamydia Infections / Q000097:blood / Q000276:immunology*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D011247:Pregnancy; D044967:Serum / Q000276:immunology; D012756:Sheep; D037521:Virulence Factors / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; D037521:Virulence Factors