title: Cytokine profiles in pregnant gilts experimentally infected with porcine reproductive and respiratory syndrome virus and relationships with viral load and fetal outcome.
abstract: In spite of extensive research, immunologic control mechanisms against Porcine Reproductive and Respiratory Syndrome virus (PRRSv) remain poorly understood. Cytokine responses have been exhaustively studied in nursery pigs and show contradictory results. Since no detailed reports on cytokine responses to PRRSv in pregnant females exist, the objectives of this study were to compare host cytokine responses between PRRSv-infected and non-infected pregnant gilts, and to investigate relationships between cytokine levels in infected gilts and viral load or fetal mortality rate. Serum samples and supernatants of peripheral blood mononuclear cells (PBMC) either stimulated with PRRSv or phorbol myristate acetate/Ionomycin (PMA/Iono) were analyzed for cytokines/chemokines: interleukins (IL) 1-beta (IL1β), IL4, IL8, IL10, IL12, chemokine ligand 2 (CCL2), interferon alpha (IFNα) and interferon gamma (IFNγ). Three cytokines (IFNα, CCL2, IFNγ) in gilt serum differed significantly in inoculated versus control gilts over time. In supernatants of PRRSv stimulated PBMC from PRRSv-infected gilts, levels of IFNα were significantly decreased, while IL8 secretion was significantly increased. PRRSv infection altered the secretion of all measured cytokines, with the exception of IFNα, from PBMC after mitogen stimulation, indicating a possible immunomodulatory effect of PRRSv. IFNα, CCL2, and IFNγ in serum, and IFNγ in supernatants of PMA/Iono stimulated PBMC were significantly associated with viral load in tissues, serum or both. However, only IFNα in supernatants of PRRSv stimulated PBMC was significantly associated with fetal mortality rate. We conclude that of the eight cytokines tested in this study IFNα was the best indicator of viral load and severity of reproductive PRRSv infection.
authors.affiliation: Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada. andrea.ladinig@usask.ca.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ladinig
authors.affiliation: U.S. Department of Agriculture, Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, Beltsville, MD, USA. joan.lunney@ars.usda.gov.
authors.forename: Joan K
authors.initials: JK
authors.lastname: Lunney
authors.affiliation: U.S. Department of Agriculture, Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, Beltsville, MD, USA. carlos.hoff-souza@embrapa.br.|EMBRAPA Pesca e Aquicultura, Palmas, TO, Brazil. carlos.hoff-souza@embrapa.br.
authors.forename: Carlos J H
authors.initials: CJ
authors.lastname: Souza
authors.affiliation: Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada. carolyn.ashley@usask.ca.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Ashley
authors.affiliation: Department of Agricultural, Food, and Nutritional Science, Faculty of Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, AB, Canada. graham.plastow@ales.ualberta.ca.
authors.forename: Graham
authors.initials: G
authors.lastname: Plastow
authors.affiliation: Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada. john.harding@usask.ca.
authors.forename: John C S
authors.initials: JC
authors.lastname: Harding
mesh_terms: D000818:Animals; D016207:Cytokines / Q000097:blood*; D005260:Female; D015759:Ionomycin / Q000494:pharmacology*; D019318:Porcine Reproductive and Respiratory Syndrome / Q000097:blood / Q000276:immunology* / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology / Q000502:physiology*; D011247:Pregnancy; D013552:Swine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D019562:Viral Load
chemical_list: D016207:Cytokines; D015759:Ionomycin; D013755:Tetradecanoylphorbol Acetate