PDF(Pubmed)
Abstract：
Bovine mastitis remains a major disease in cattle world-wide. In the mammary gland, mammary epithelial cells (MEC) are sentinels equipped with receptors allowing them to detect and respond to the invasion by bacterial pathogens, in particular Escherichia coli. Lipopolysaccharide (LPS) is the major E. coli motif recognized by MEC through its interaction with the TLR4 receptor and the CD14 co-receptor. Previous studies have highlighted the role of soluble CD14 (sCD14) in the efficient recognition of LPS molecules possessing a full-length O-antigen (LPSS). We demonstrate here that MEC are able to secrete CD14 and are likely to contribute to the presence of sCD14 in milk. We then investigated how sCD14 modulates and is required for the response of MEC to LPSS. This study highlights the key role of sCD14 for the full activation of the Myd88-independent pathway by LPSS. We also identified several lncRNA that are activated in MEC in response to LPS, including one lncRNA showing homologies with the mir-99a-let-7c gene (MIR99AHG). Altogether, our results show that a full response to LPS by mammary epithelial cells requires sCD14 and provide detailed information on how milk sCD14 can contribute to an efficient recognition of LPS from coliform pathogens.
摘要：
牛乳腺炎仍然是世界范围内牛的主要疾病。在乳腺里,乳腺上皮细胞（MEC）是配备有受体的哨兵，使它们能够检测和响应细菌病原体的入侵，特别是大肠杆菌。脂多糖(LPS)是MEC通过其与TLR4受体和CD14共受体的相互作用而识别的主要大肠杆菌基序。先前的研究已经强调了可溶性CD14(sCD14)在具有全长O-抗原(LPSS)的LPS分子的有效识别中的作用。我们在此证明MEC能够分泌CD14，并且可能有助于牛奶中sCD14的存在。然后，我们研究了sCD14如何调节以及MEC对LPSS的反应是必需的。这项研究强调了sCD14在LPSS完全激活Myd88非依赖性途径中的关键作用。我们还鉴定了几种在MEC中响应LPS而被激活的lncRNA，包括一个显示与mir-99a-let-7c基因同源的lncRNA(MIR99AHG)。总之,我们的结果表明,乳腺上皮细胞对LPS的完全反应需要sCD14,并提供了有关牛奶sCD14如何有助于从大肠杆菌病原体中有效识别LPS的详细信息.
