HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Interpretive Summary Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Griesbeck-Zilch, B. Articles by Wellnitz, O. PubMed PubMed Citation Articles by Griesbeck-Zilch, B. Articles by Wellnitz, O.

Staphylococcus aureus and Escherichia coli Cause Deviating Expression Profiles of Cytokines and Lactoferrin Messenger Ribonucleic Acid in Mammary Epithelial Cells

B. Griesbeck-Zilch^*, H. H. D. Meyer^*, CH. Kühn, M. Schwerin and O. Wellnitz^,1

^* Physiology Weihenstephan, Technical University Munich, D-85350 Freising, Germany
Research Institute for the Biology of Farm Animals, D-18196 Dummerstorf, Germany
Veterinary Physiology, Vetsuisse Faculty, University of Bern, CH-1725 Posieux, Switzerland

¹ Corresponding author: olga.wellnitz{at}physio.unibe.ch

Pathogens invading the mammary gland cause a complex signaling network that activates the early immune defense and leads to an outcome of inflammation symptoms. To examine the importance of mammary epithelial cells in these regulations and interactions resulting in a pathogen-related course of mastitis, we characterized the mRNA expression profile of key molecules of the innate immune system by quantitative real-time PCR. Mammary gland epithelial cells isolated on d 42 of lactation from 28 first-lactation Holstein dairy cows were cultured separately under standardized conditions and treated for 1, 6, and 24 h with heat-inactivated gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. Both pathogens increased mRNA expression patterns of proteins involved in pathogen recognition such as Toll-like receptors and nuclear factor- B, whereas gram-negatives acted as a stronger stimulus. Furthermore, this could be confirmed by the expression profile of the proinflammatory cytokines tumor necrosis factor alpha, IL-1 beta, IL-6, and chemokines such as IL-8 and RANTES (regulated upon activation, normal T-cell expressed and secreted). Remarkably, at a low level of mRNA expression after 1 h of treatment these cytokines and chemokines were expressed at a significantly higher level in Staphyloccocus aureus than in Escherichia coli affected cells. Lactoferrin showed a deviating expression pattern to pathogen stimulation (i.e., at the 1-h measuring point Escherichia coli induced a higher mRNA expression, whereas the highest level was reached after 24 h of stimulation with Staphylococcus aureus). Complement factor 3 was the only measured factor that responded equally to both microorganisms. Our data emphasize the role of mammary epithelial cells in the immune defense of the udder and confirm their contribution to pathogen-related different courses of mastitis.

Key Words: mammary epithelial cell • cytokine • lactoferrin