title: Chlamydia suis and Chlamydia trachomatis induce multifunctional CD4 T cells in pigs.
abstract: Chlamydia trachomatis infections are the most prominent bacterial sexually-transmitted disease world-wide and a lot of effort is put into the development of an effective vaccine. Pigs have been shown to be a valuable animal model for C. trachomatis vaccine development. The aim of this study was to decipher the T-cell-mediated immune response to chlamydial infections including C. trachomatis and C. suis, the chlamydia species naturally infecting pigs with a demonstrated zoonotic potential. Vaginal infection of pigs with C. suis and C. trachomatis lasted from 3 to 21days and intra-uterine infection was still present after 21days in 3 out of 5 C. suis- and 4 out of 5 C. trachomatis-inoculated animals and caused severe pathological changes. Humoral immune responses including neutralizing antibodies were found predominantly in response to C. suis starting at 14days post inoculation. The T-cell-mediated immune responses to C. trachomatis and C. suis-infections started at 7days post inoculation and consisted mainly of CD4+T cells which were either IFN-γ single cytokine-producing or IFN-γ/TNF-α double cytokine-producing T-helper 1 cells. IL-17-producing CD4+T cells were rare or completely absent. The T-cell-mediated immune responses were triggered by both homologous or heterologous re-stimulation indicating that cross-protection between the two chlamydia species is possible. Thus, having access to a working genital C. suis and C. trachomatis infection model, efficient monitoring of the host-pathogen interactions, and being able to accurately assess the responses to infection makes the pig an excellent animal model for vaccine development which also could bridge the gap to the clinical phase for C. trachomatis vaccine research.
authors.affiliation: Vaccine and Infectious Disease Organization - International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, S7N 5E3 Saskatoon, Saskatchewan, Canada; Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, 27607 Raleigh, NC, USA. Electronic address: tekaeser@ncsu.edu.
authors.forename: T
authors.initials: T
authors.lastname: Käser
authors.affiliation: Vaccine and Infectious Disease Organization - International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, S7N 5E3 Saskatoon, Saskatchewan, Canada.
authors.forename: J A
authors.initials: JA
authors.lastname: Pasternak
authors.affiliation: Vaccine and Infectious Disease Organization - International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, S7N 5E3 Saskatoon, Saskatchewan, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Delgado-Ortega
authors.affiliation: Vaccine and Infectious Disease Organization - International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, S7N 5E3 Saskatoon, Saskatchewan, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Hamonic
authors.affiliation: Vaccine and Infectious Disease Organization - International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, S7N 5E3 Saskatoon, Saskatchewan, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Lai
authors.affiliation: Vaccine and Infectious Disease Organization - International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, S7N 5E3 Saskatoon, Saskatchewan, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Erickson
authors.affiliation: Vaccine and Infectious Disease Organization - International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, S7N 5E3 Saskatoon, Saskatchewan, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Walker
authors.affiliation: Vaccine and Infectious Disease Organization - International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, S7N 5E3 Saskatoon, Saskatchewan, Canada.
authors.forename: J R
authors.initials: JR
authors.lastname: Dillon
authors.affiliation: Vaccine and Infectious Disease Organization - International Vaccine Centre (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, S7N 5E3 Saskatoon, Saskatchewan, Canada.
authors.forename: V
authors.initials: V
authors.lastname: Gerdts
authors.affiliation: LUNAM Université, Oniris, Nantes-Atlantic College of Veterinary Medicine and Food Sciences and Engineering, UMR BioEpAR, F-44307 Nantes, France; INRA, UMR1300 Biology, Epidemiology and Risk Analysis in Animal Health, CS 40706, F-44307 Nantes, France.
authors.forename: F
authors.initials: F
authors.lastname: Meurens
mesh_terms: D000282:Administration, Intravaginal; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000917:Antibody Formation; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002689:Chlamydia / Q000276:immunology* / Q000472:pathogenicity; D002690:Chlamydia Infections / Q000276:immunology / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D016207:Cytokines / Q000378:metabolism; D054884:Host-Pathogen Interactions; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D013552:Swine; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial; D016207:Cytokines
keywords: Animal model; Chlamydia suis; Chlamydia trachomatis; One Health; Swine; Vaccine development