LBP and CD14 secreted in tears by the lacrimal glands modulate the LPS response of corneal epithelial cells
LBP and CD14 secreted in tears by the lacrimal glands modulate the LPS response of corneal epithelial cells
复制标题
DOI：
10.1167/iovs.05-0543
复制
发表时间：
2005-11-01
影响因子：
4.4
通讯作者：
Altosaar, I
中科院分区：
文献类型：
--
作者：
Blais, DR;Vascotto, SG;Altosaar, I
目的。就促炎特性而言，脂多糖（LPS）是最强大的细菌毒力因子之一，并且可能导致角膜细菌性角膜炎。更好地了解泪液-角膜界面处 LPS 受体成分的空间表达可能有助于增强 LPS 受体复合物在眼部防御革兰氏阴性感染方面的功能。方法。通过 ELISA、RT-PCR、Western blot 分析和免疫荧光检测人泪腺、反射泪液和角膜上皮中 LPS 结合蛋白 (LBP)、CD14、Toll 样受体 (TLR)-4 和 MD-2 的表达。用LPS和人泪液激活原代和永生化角膜上皮细胞后促炎细胞因子的释放通过ELISA测量。结果。在人类反射性眼泪中检测到 LBP 和 CD14 蛋白。人泪腺和角膜上皮表达 LBP、CD14、TLR4 和 MD-2 mRNA 和蛋白质。在角膜上皮中，LBP主要由浅层和基底上皮细胞表达，而CD14、TLR4和MD-2表达仅限于翼部和基底上皮细胞。当受到 LPS 攻击时，泪液 CD14 和 LBP 以剂量依赖性方式介导角膜上皮细胞分泌白细胞介素 (IL)-6 和 IL-8。结论。泪液 CD14 和 LBP 与角膜上皮表达的 LPS 受体复合物互补，在 LPS 存在的情况下触发免疫反应。这些泪液和角膜免疫蛋白的互补可以在 LPS 识别和信号传导中发挥重要作用，因此可以调节眼部先天免疫。
PURPOSE. Lipopolysaccharide (LPS) is one of the most powerful bacterial virulence factors in terms of proinflammatory properties and is likely to contribute to corneal bacterial keratitis. Better understanding of the spatial expression of the LPS receptor components at the tear - corneal interface might facilitate enhanced functions of the LPS receptor complex in ocular defense against Gram-negative infections.METHODS. The expression of LPS-binding protein (LBP), CD14, toll-like receptor (TLR)-4, and MD-2 in human lacrimal glands, reflex tears, and corneal epithelia was examined by ELISA, RT-PCR, Western blot analysis, and immunofluorescence. The release of proinflammatory cytokines after the activation of primary and immortalized corneal epithelial cells with LPS and human tears was measured by ELISA.RESULTS. LBP and CD14 proteins were detected in reflex human tears. Human lacrimal glands and corneal epithelia expressed LBP, CD14, TLR4, and MD-2 mRNAs and proteins. In the corneal epithelium, LBP was mainly expressed by superficial and basal epithelial cells, whereas CD14, TLR4, and MD-2 expression were limited to the wing and basal epithelial cells. In a dose-dependant manner, tear CD14 and LBP mediated the secretion of interleukin (IL)-6 and IL-8 by corneal epithelia cells when challenged with LPS.CONCLUSIONS. Tear CD14 and LBP complemented the LPS receptor complex expressed by the corneal epithelia to trigger an immune response in the presence of LPS. The complementation of these tear and corneal immune proteins could play an important role in LPS recognition and signaling and, therefore, could modulate ocular innate immunity.