title: Immunomodulatory factors and infectious agents associated with the hepatic gene expression of the IGF system in nursery pigs.
abstract: Recent findings suggest there is a complex interaction between the IGF system and the inflammatory immune response. The objective of this study was to determine whether gene expression of growth factors (IGF-1, IGF-binding protein-3 (IGFBP-3) and growth hormone receptors (GHR)) in the liver is associated with gene expression of immunomodulators in the liver, including C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin (Hp), interferon-α (IFN-α), IFN-γ, tumour necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, IL-10 and IL-18, as well as with the presence of Salmonella spp., Lawsonia intracellularis, Brachyspira spp., enterotoxigenic Escherichia coli, methicillin-resistant Staphylococcus aureus, swine influenza virus, and porcine reproductive and respiratory syndrome virus (PRRSV) in nursery pigs (n=74) from commercial farms (n=4). Gene expression was quantified using reverse transcription quantitative-PCR (RT-qPCR) and the data were modelled using logistic regression methods. Pigs with elevated IGF-1 expression were less likely to have increased expression of TNF-α (odds ratio (OR)=0.14, P<0.01) and IL-18 (OR=0.19, P<0.05), and less likely to be colonized with PRRSV (OR=0.03, P<0.01). Pigs with increased expression of IGFBP-3 were more likely to have elevated IL-6 expression (OR=8.5, P<0.05). It was also observed that IGFBP-3 and IGF-1 were significantly associated when Hp expression was low (OR=30, P<0.05), but this association was not significant when Hp expression was high (P=0.54). Pigs with increased expression of GHR were less likely to have elevated expression of SAA (OR=0.01, P<0.05) and IL-1β (OR=0.03, P<0.05), but more likely to have increased expression of CRP (OR=290, P<0.01). Overall, there appears to be an inverse association between the hepatic expression of the IGF system (IGF-1, IGFBP-3, GHR) and certain cytokines (IL-1β, IL-18, TNF-α) and acute-phase proteins (SAA, Hp).
authors.affiliation: 1 Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1.
authors.forename: M J
authors.initials: MJ
authors.lastname: Slifierz
authors.affiliation: 1 Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1.
authors.forename: R
authors.initials: R
authors.lastname: Friendship
authors.affiliation: 2 Department of Animal and Poultry Science, University of Guelph, Guelph, ON, Canada, N1G 2W1.
authors.forename: C F M
authors.initials: CF
authors.lastname: de Lange
authors.affiliation: 3 Animal Health Laboratory, Ontario Veterinary College, University of Guelph, ON, Canada, N1G 2W1.
authors.forename: D
authors.initials: D
authors.lastname: Slavic
authors.affiliation: 1 Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1.
authors.forename: H
authors.initials: H
authors.lastname: Grgic
authors.affiliation: 1 Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1.
authors.forename: A
authors.initials: A
authors.lastname: Farzan
mesh_terms: D000209:Acute-Phase Proteins / Q000235:genetics; D000818:Animals; D017400:Brachyspira / Q000276:immunology; D016207:Cytokines / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation; D006242:Haptoglobins / Q000378:metabolism; D007155:Immunologic Factors / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D020639:Lawsonia Bacteria / Q000276:immunology; D008099:Liver / Q000378:metabolism; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000276:immunology; D009975:Orthomyxoviridae / Q000276:immunology; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology; D011897:Random Allocation; D011986:Receptors, Somatotropin / Q000235:genetics*; D012475:Salmonella / Q000276:immunology; D013552:Swine / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000502:physiology*; D013553:Swine Diseases / Q000276:immunology* / Q000382:microbiology
chemical_list: D000209:Acute-Phase Proteins; D016207:Cytokines; D006242:Haptoglobins; D007155:Immunologic Factors; D011986:Receptors, Somatotropin; D007334:Insulin-Like Growth Factor I