title: Experimental Staphylococcus aureus infection of the mammary gland induces region-specific changes in innate immune gene expression.
abstract: Staphylococcus aureus is a prolific mastitis-causing bacterium that resides naturally in the environment of the dairy cow. The aim of this study was to profile immune gene expression in tissue from the alveolar, ductal, gland cistern and teat canal regions of the bovine mammary gland following intramammary infection with S. aureus. Quantitative real-time PCR (qPCR) was used to profile expression of innate immune genes including pattern recognition receptors (PRRs), cytokines, antimicrobial peptides (AMPs) and acute phase proteins (APPs). Consistent expression of Toll-like receptors (TLRs) 1-10 and NOD-like receptors (NODs) 1-2 was detected in all four tissue regions. Pro-inflammatory cytokines (IL6, IL17A and IL8) and anti-inflammatory cytokine (IL10) were induced in all 4 tissues. APP (SAA3 and HP) and AMP (DEFB4 and DEFB5) genes showed the greatest induction throughout the mammary gland in response to S. aureus, with particularly high expression in alveolar tissue (SAA3 and HP >133- and >80-fold respectively, P<0.05; DEFB4 and DEFB5 >9- and >27-fold respectively, P<0.05). Collectively, our data show both sentinel and effector immune functions throughout the mammary gland in response to S. aureus challenge.
authors.affiliation: Comparative Immunology Group, School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland.
authors.forename: Cormac J
authors.initials: CJ
authors.lastname: Whelehan
authors.forename: Kieran G
authors.initials: KG
authors.lastname: Meade
authors.forename: P David
authors.initials: PD
authors.lastname: Eckersall
authors.forename: Fiona J
authors.initials: FJ
authors.lastname: Young
authors.forename: Cliona
authors.initials: C
authors.lastname: O'Farrelly
mesh_terms: D000209:Acute-Phase Proteins / Q000235:genetics; D000818:Animals; D002417:Cattle; D016207:Cytokines / Q000235:genetics; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D007113:Immunity, Innate / Q000235:genetics*; D008321:Mammary Glands, Animal / Q000276:immunology* / Q000378:metabolism; D008414:Mastitis, Bovine / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D008892:Milk / Q000166:cytology / Q000276:immunology; D053474:Nod1 Signaling Adaptor Protein / Q000235:genetics; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics; D013203:Staphylococcal Infections / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000662:veterinary*; D051193:Toll-Like Receptors / Q000235:genetics; D023083:beta-Defensins / Q000235:genetics
chemical_list: D000209:Acute-Phase Proteins; D016207:Cytokines; D053474:Nod1 Signaling Adaptor Protein; D053473:Nod2 Signaling Adaptor Protein; D051193:Toll-Like Receptors; D023083:beta-Defensins