title: Response of the goat mammary gland to infection with Staphylococcus aureus revealed by gene expression profiling in milk somatic and white blood cells.
abstract: BACKGROUND
  S. aureus is one of the main pathogens responsible for the intra-mammary infection in dairy ruminants. Although much work has been carried out to understand the complex physiological and cellular events that occur in the mammary gland in response to S. aureus, the protective mechanisms are still poorly understood. The objectives of the present study were to investigate gene expression during the early response of the goat mammary gland to an experimental challenge with S. aureus, in order to better understand the local and systemic response and to compare them in two divergent lines of goat selected for high and low milk somatic cell scores.
  
  
  RESULTS
  No differences in gene expression were found between high and low SCS (Somatic Cells Score) selection lines. Analysing the two groups together, an expression of 300 genes were found to change from T0 before infection, and T4 at 24 hours and T5 at 30 hours following challenge. In blood derived white blood cells 8 genes showed increased expression between T0 and T5 and 1 gene has reduced expression. The genes showing the greatest increase in expression following challenge (5.65 to 3.16 fold change) play an important role in (i) immune and inflammatory response (NFKB1, TNFAIP6, BASP1, IRF1, PLEK, BATF3); (ii) the regulation of innate resistance to pathogens (PTX3); and (iii) the regulation of cell metabolism (CYTH4, SLC2A6, ARG2). The genes with reduced expression (-1.5 to -2.5 fold) included genes involved in (i) lipid metabolism (ABCG2, FASN), (ii) chemokine, cytokine and intracellular signalling (SPPI), and (iii) cell cytoskeleton and extracellular matrix (KRT19).
  
  
  CONCLUSIONS
  Analysis of genes with differential expression following infection showed an inverse relationship between immune response and lipid metabolism in the early response of the mammary gland to the S. aureus challenge. PTX3 showed a large change in expression in both milk and blood, and is therefore a candidate for further studies on immune response associated with mastitis.
authors.affiliation: Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Lodi, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Cremonesi
authors.forename: Rossana
authors.initials: R
authors.lastname: Capoferri
authors.forename: Giuliano
authors.initials: G
authors.lastname: Pisoni
authors.forename: Marcello
authors.initials: M
authors.lastname: Del Corvo
authors.forename: Francesco
authors.initials: F
authors.lastname: Strozzi
authors.forename: Rachel
authors.initials: R
authors.lastname: Rupp
authors.forename: Hugues
authors.initials: H
authors.lastname: Caillat
authors.forename: Paola
authors.initials: P
authors.lastname: Modesto
authors.forename: Paolo
authors.initials: P
authors.lastname: Moroni
authors.forename: John L
authors.initials: JL
authors.lastname: Williams
authors.forename: Bianca
authors.initials: B
authors.lastname: Castiglioni
authors.forename: Alessandra
authors.initials: A
authors.lastname: Stella
mesh_terms: D000818:Animals; D002097:C-Reactive Protein / Q000235:genetics / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000276:immunology; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D015511:Goat Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D006041:Goats; D006801:Humans; D007962:Leukocytes / Q000166:cytology / Q000378:metabolism* / Q000382:microbiology; D050356:Lipid Metabolism / Q000235:genetics / Q000276:immunology; D008321:Mammary Glands, Animal / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D008413:Mastitis / Q000235:genetics* / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D008892:Milk / Q000166:cytology / Q000382:microbiology; D000683:Serum Amyloid P-Component / Q000235:genetics / Q000378:metabolism; D013203:Staphylococcal Infections / Q000235:genetics* / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000502:physiology; D000099153:Pentraxins
chemical_list: D002097:C-Reactive Protein; D016207:Cytokines; D000683:Serum Amyloid P-Component; D000099153:Pentraxins