CD14 is expressed and released as soluble CD14 by human intestinal epithelial cells in vitro:: Lipopolysaccharide activation of epithelial cells revisited
CD14 is expressed and released as soluble CD14 by human intestinal epithelial cells in vitro:: Lipopolysaccharide activation of epithelial cells revisited
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DOI：
10.1128/iai.69.6.3772-3781.2001
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发表时间：
2001-06-01
影响因子：
3.1
通讯作者：
Tlaskalová-Hogenová, H
中科院分区：
文献类型：
--
作者：
Funda, DP;Tucková, L;Tlaskalová-Hogenová, H
人内皮细胞和上皮细胞显示出对脂多糖（LPS）的响应。然而，这些所谓的CD 14阴性细胞的CD 14表达和释放尚未详细研究。我们研究了三种人肠上皮细胞系（ECL）SW-480、HT-29和Caco-2的CD 14和CD 11 c/CD 18表达及其对内毒素的反应性。活化细胞分选仪分析显示，HT-29、Caco-2和SW-480 ECL上无CD 11 c/CD 18表达，但膜结合CD 14表达较低。Western blotting和RT-PCR均证实了所有三种肠ECL的CD 14阳性。在用范围从0.01 ng/ml到100 μ g/ml的10倍系列稀释的LPS培养6、8、18、24和48 h后，没有实现CD 14表达的实质性调节。有趣的是，在所有三种ECL的组织培养上清液中均发现了可溶性CD 14。最后，只有HT-29和SW-4801而不是Caco-21细胞通过释放白细胞介素8对LPS暴露（范围，0.01 ng/ml至100 μ g/ml）作出反应。因此，我们发现HT-29、SW-480和Caco-2人肠ECL表达膜结合的CD 14。由于Caco-2细胞对LPS无反应，这些细胞系可能是研究LPS受体复合物的有趣模型。人肠上皮细胞不仅能够表达而且能够释放可溶性CD 14的事实可能在体内具有重要意义，例如，在形成粘膜免疫系统和肠道中的细菌之间的相互作用和/或在内毒素休克的发病机制中。
Human endothelial as well as epithelial cells were shown to respond to lipopolysaccharides (LPSs). However, the expression and release of CD14 by these so-called CD14-negative cells have not been studied in detail. We investigated three human intestinal epithelial cell lines (ECLs), SW-480, HT-29, and Caco-2, for their expression of CD14 and CD11c/CD18 as well as their responsiveness to endotoxins. Fluorescence-activated cell sorter analysis revealed no expression of CD11c/CD18, but there was low expression of membrane-bound CD14 on HT-29, Caco-2, and SW-480 ECLs. Both Western blotting and reverse transcription-PCR confirmed the CD14 positivity of all three intestinal ECLs. No substantial modulation of CD14 expression was achieved after 6, 8, 18, 24, and 48 h of cultivation with 10-fold serial dilutions of LPS ranging from 0.01 ng/ml to 100 mug/ml. Interestingly, soluble CD14 was found in the tissue culture supernatants of all three ECLs. Finally, only HT-29 and SW-4801 and not Caco-21 cells; responded to LPS exposure (range, 0.01 ng/ml to 100 mug/ml) by interleukin 8 release. Thus, we show that HT-29, SW-480, and Caco-2 human intestinal ECLs express membrane-bound CD14. As Caco-2 cells did not respond to LPS, these cell lines might be an interesting model for studying the receptor complex for LPS. The fact that human intestinal epithelial cells are capable not only of expression but also of release of soluble CD14 may have important implications in vivo, e.g., in shaping the interaction between the mucosal immune system and bacteria in the gut and/or in the pathogenesis of endotoxin shock.