1. Repertoire of Escherichia coli agonists sensed by innate immunity receptors of the bovine udder and mammary epithelial cells
- Author
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Perrine Roussel, Angélina Trotereau, Adeline Porcherie, Pierre Germon, Florence B. Gilbert, Patricia Cunha, Pascal Rainard, Infectiologie et Santé Publique (UMR ISP), Institut National de la Recherche Agronomique (INRA)-Université de Tours, and Institut National de la Recherche Agronomique (INRA)-Université de Tours (UT)
- Subjects
bovin ,MAMMITE ,040301 veterinary sciences ,medicine.disease_cause ,Polymerase Chain Reaction ,Microbiology ,0403 veterinary science ,03 medical and health sciences ,Mammary Glands, Animal ,NOD1 ,Escherichia coli ,medicine ,Animals ,Udder ,Receptor ,Mastitis, Bovine ,Cells, Cultured ,Escherichia coli Infections ,030304 developmental biology ,bactérie ,0303 health sciences ,[SDV.BA.MVSA]Life Sciences [q-bio]/Animal biology/Veterinary medicine and animal Health ,lcsh:Veterinary medicine ,Innate immune system ,General Veterinary ,biology ,système immunitaire inné ,Escherichia coli Proteins ,Research ,Toll-Like Receptors ,Epithelial Cells ,04 agricultural and veterinary sciences ,veterinary(all) ,Immunity, Innate ,3. Good health ,CARD Signaling Adaptor Proteins ,TLR2 ,Médecine vétérinaire et santé animal ,medicine.anatomical_structure ,TLR5 ,biology.protein ,glande mammaire ,lcsh:SF600-1100 ,Veterinary medicine and animal Health ,Cattle ,Female ,Flagellin - Abstract
Escherichia coli is a frequent cause of clinical mastitis in dairy cows. It has been shown that a prompt response of the mammary gland after E. coli entry into the lumen of the gland is required to control the infection, which means that the early detection of bacteria is of prime importance. Yet, apart from lipopolysaccharide (LPS), little is known of the bacterial components which are detected by the mammary innate immune system. We investigated the repertoire of potential bacterial agonists sensed by the udder and bovine mammary epithelial cells (bMEC) during E. coli mastitis by using purified or synthetic molecular surrogates of bacterial agonists of identified pattern-recognition receptors (PRRs). The production of CXCL8 and the influx of leucocytes in milk were the readouts of reactivity of stimulated cultured bMEC and challenged udders, respectively. Quantitative PCR revealed that bMEC in culture expressed the nucleotide oligomerization domain receptors NOD1 and NOD2, along with the Toll-like receptors TLR1, TLR2, TLR4, and TLR6, but hardly TLR5. In line with expression data, bMEC proved to react to the cognate agonists C12-iE-DAP (NOD1), Pam3CSK4 (TLR1/2), Pam2CSK4 (TLR2/6), pure LPS (TLR4), but not to flagellin (TLR5). As the udder reactivity to NOD1 and TLR5 agonists has never been reported, we tested whether the mammary gland reacted to intramammary infusion of C12-iE-DAP or flagellin. The udder reacted to C12-iE-DAP, but not to flagellin, in line with the reactivity of bMEC. These results extend our knowledge of the reactivity of the bovine mammary gland to bacterial agonists of the innate immune system, and suggest that E. coli can be recognized by several PRRs including NOD1, but unexpectedly not by TLR5. The way the mammary gland senses E. coli is likely to shape the innate immune response and finally the outcome of E. coli mastitis.
- Published
- 2012