title: The impact of breed and tissue compartment on the response of pig macrophages to lipopolysaccharide.
abstract: BACKGROUND
  The draft genome of the domestic pig (Sus scrofa) has recently been published permitting refined analysis of the transcriptome. Pig breeds have been reported to differ in their resistance to infectious disease. In this study we examine whether there are corresponding differences in gene expression in innate immune cells
  
  
  RESULTS
  We demonstrate that macrophages can be harvested from three different compartments of the pig (lungs, blood and bone-marrow), cryopreserved and subsequently recovered and differentiated in CSF-1. We have performed surface marker analysis and gene expression profiling on macrophages from these compartments, comparing twenty-five animals from five different breeds and their response to lipopolysaccharide. The results provide a clear distinction between alveolar macrophages (AM) and monocyte-derived (MDM) and bone-marrow-derived macrophages (BMDM). In particular, the lung macrophages express the growth factor, FLT1 and its ligand, VEGFA at high levels, suggesting a distinct pathway of growth regulation. Relatively few genes showed breed-specific differential expression, notably CXCR2 and CD302 in alveolar macrophages. In contrast, there was substantial inter-individual variation between pigs within breeds, mostly affecting genes annotated as being involved in immune responses.
  
  
  CONCLUSIONS
  Pig macrophages more closely resemble human, than mouse, in their set of macrophage-expressed and LPS-inducible genes. Future research will address whether inter-individual variation in macrophage gene expression is heritable, and might form the basis for selective breeding for disease resistance.
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, Edinburgh EH25 9RG, United Kingdom. david.hume@roslin.ed.ac.uk.
authors.forename: Ronan
authors.initials: R
authors.lastname: Kapetanovic
authors.forename: Lynsey
authors.initials: L
authors.lastname: Fairbairn
authors.forename: Alison
authors.initials: A
authors.lastname: Downing
authors.forename: Dario
authors.initials: D
authors.lastname: Beraldi
authors.forename: David P
authors.initials: DP
authors.lastname: Sester
authors.forename: Tom C
authors.initials: TC
authors.lastname: Freeman
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Tuggle
authors.forename: Alan L
authors.initials: AL
authors.lastname: Archibald
authors.forename: David A
authors.initials: DA
authors.lastname: Hume
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000276:immunology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000276:immunology; D006706:Homeostasis / Q000276:immunology; D007113:Immunity, Innate / Q000235:genetics; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D016676:Macrophages, Alveolar / Q000276:immunology* / Q000378:metabolism; D005810:Multigene Family; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity; D025341:Principal Component Analysis; D013045:Species Specificity; D034421:Sus scrofa / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D059467:Transcriptome
chemical_list: D008070:Lipopolysaccharides