Griesbeck-Zilch B, Meyer H H D, Kühn C H, Schwerin M, Wellnitz O
Physiology Weihenstephan, Technical University Munich, D-85350 Freising, Germany.
J Dairy Sci. 2008 Jun;91(6):2215-24. doi: 10.3168/jds.2007-0752.
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-kappa 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.
入侵乳腺的病原体引发复杂的信号网络，激活早期免疫防御并导致炎症症状。为了研究乳腺上皮细胞在这些调节和相互作用中的重要性，这些调节和相互作用导致了与病原体相关的乳腺炎病程，我们通过定量实时PCR对先天免疫系统关键分子的mRNA表达谱进行了表征。从28头初产荷斯坦奶牛泌乳第42天分离的乳腺上皮细胞在标准化条件下单独培养，并用热灭活的革兰氏阳性菌（金黄色葡萄球菌）和革兰氏阴性菌（大肠杆菌）处理1、6和24小时。两种病原体均增加了参与病原体识别的蛋白质的mRNA表达模式，如Toll样受体和核因子-κB，而革兰氏阴性菌作为更强的刺激物。此外，促炎细胞因子肿瘤坏死因子α、白细胞介素-1β、白细胞介素-6以及趋化因子如白细胞介素-8和调节激活正常T细胞表达和分泌的趋化因子（RANTES）的表达谱也证实了这一点。值得注意的是，在处理1小时后mRNA表达水平较低时，这些细胞因子和趋化因子在金黄色葡萄球菌感染的细胞中的表达水平明显高于大肠杆菌感染的细胞。乳铁蛋白对病原体刺激表现出不同的表达模式（即，在1小时测量点，大肠杆菌诱导更高的mRNA表达，而在金黄色葡萄球菌刺激24小时后达到最高水平）。补体因子3是唯一对两种微生物反应相同的测量因子。我们的数据强调了乳腺上皮细胞在乳房免疫防御中的作用，并证实了它们对与病原体相关的不同乳腺炎病程的贡献。
