Roles of human β-defensins in innate immune defense at the ocular surface: arming and alarming corneal and conjunctival epithelial cells
Roles of human β-defensins in innate immune defense at the ocular surface: arming and alarming corneal and conjunctival epithelial cells
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DOI：
10.1007/s00418-010-0713-y
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发表时间：
2010-07-01
影响因子：
2.3
通讯作者：
Paulsen, Friedrich P.
中科院分区：
文献类型：
--
作者：
Garreis, Fabian;Schlorf, Thomas;Paulsen, Friedrich P.
人β -防御素是由上皮细胞产生的阳离子肽，被认为是粘膜表面免疫功能的重要组成部分。本研究在体外和体内研究了β -防御素在眼表的表达和诱导性。采用RT-PCR和免疫组化方法检测人β -防御素（hBD）在眼表和泪腺组织中的表达。用促炎细胞因子和不同眼部病原体的上清液刺激培养的角膜和结膜上皮细胞。采用Real-time PCR和ELISA实验研究其对hBD2和3诱导性的影响。采用免疫组织化学方法检测小鼠β -防御素-2、-3和-4 （mBD2-4）在经临床金黄色葡萄球菌（SA）分离物上清处理和未处理的小鼠眼表划伤模型中的表达和诱导性。本研究表明，hBD1、-2、-3和-4在结膜上皮细胞中组成性表达，在角膜中也部分表达。眼表、泪腺和人眼泪的健康组织中含有可测量的hBD2和-3，角膜中的浓度最高，而所有其他组织，特别是眼泪中的浓度要低得多，这表明上皮内储存了β -防御素。将培养的人角膜和结膜上皮细胞暴露于促炎细胞因子和各种细菌的上清液中，发现IL-1 β是hBD2的强诱导剂，金黄色葡萄球菌增加了角膜和结膜上皮细胞中hBD2和hBD3的产生。小鼠角膜划伤模型表明，β -防御素只有在泪膜内的微生物产物与有缺陷的上皮接触时才会被诱导。我们的发现表明，泪膜本身含有如此多的抗菌物质，上皮诱导β -防御素只发生在眼表损伤的结果。这些发现扩大了我们对-防御素在眼表和泪腺的分布、数量和诱导性的认识，并显示了-防御素是如何被特异性调节的。
Human beta-defensins are cationic peptides produced by epithelial cells that have been proposed to be an important component of immune function at mucosal surfaces. In this study, the expression and inducibility of beta-defensins at the ocular surface were investigated in vitro and in vivo. Expression of human beta-defensins (hBD) was determined by RT-PCR and immunohistochemistry in tissues of the ocular surface and lacrimal apparatus. Cultured corneal and conjunctival epithelial cells were stimulated with proinflammatory cytokines and supernatants of different ocular pathogens. Real-time PCR and ELISA experiments were performed to study the effect on the inducibility of hBD2 and 3. Expression and inducibility of mouse beta-defensins-2, -3 and -4 (mBD2-4) were tested in a mouse ocular surface scratch model with and without treatment of supernatants of a clinical Staphylococcus aureus (SA) isolate by means of immunohistochemistry. Here we show that hBD1, -2, -3 and -4 are constitutively expressed in conjunctival epithelial cells and also partly in cornea. Healthy tissues of the ocular surface, lacrimal apparatus and human tears contain measurable amounts of hBD2 and -3, with highest concentrations in cornea and much lower concentrations in all other tissues, especially tears, suggesting intraepithelial storage of beta-defensins. Exposure of cultured human corneal and conjunctival epithelial cells to proinflammatory cytokines and supernatants of various bacteria revealed that IL-1 beta is a very strong inductor of hBD2 and Staphylococcus aureus increases both hBD2 and hBD3 production in corneal and conjunctival epithelial cells. A murine corneal scratch model demonstrated that beta-defensins are only induced if microbial products within the tear film come into contact with a defective epithelium. Our finding suggests that the tear film per se contains so much antimicrobial substances that epithelial induction of beta-defensins occurs only as a result of ocular surface damage. These findings widen our knowledge of the distribution, amount and inducibility of beta-defensins at the ocular surface and lacrimal apparatus and show how beta-defensins are regulated specifically.