肿瘤坏死因子α诱导人皮肤角质形成细胞β-防御素的体外表达

背景:人β-防御素在皮肤的固有免疫中占据重要地位,同时由于其广谱的抗菌活性,从而成为抗感染临床研究中的热点。目的:观察原代培养人皮肤角质形成细胞在浓度梯度肿瘤坏死因子α的刺激下,其免疫分子β-防御素及Toll样受体的表达情况。方法:取8例30岁以下患者包皮组织,分别原代培养获取角质形成细胞,并采用浓度梯度肿瘤坏死因子α(10,50,100,150,200μg/L)进行刺激,实时荧光定量PCR检测β-防御素1,2,3及Toll样受体2,4的基因表达水平。结果与结论:肿瘤坏死因子α对β-防御素1,2,3基因表达均有明显诱导作用,且在150μg/L时达到最大效应(P<0.05),相对于对照组分别出现明显的升高,而在200μg/L时又出现明显降低,呈现出浓度依赖性趋势。肿瘤坏死因子α诱导角质形成细胞后,Toll样受体2,4的表达规律类似于β-防御素。结果可见肿瘤坏死因子α对体外培养的皮肤角质形成细胞有显著的免疫诱导效应。

Expression of human beta-defensins in skin keratinocytes under the induction of tumor necrosis factor alpha

BACKGROUND：Human β-defensin plays an important role in the innate immune of the skin.Because of its broad spectrum antibiotic activity,human β-defensin has become one of the hotspots in the clinical anti-inflammation research.OBJECTIVE：To show the inducible expression of human β-defensin and Toll-like receptor in human skin keratinocytes by graded concentrations of tumor necrosis factor alpha（TNF-α）.METHODS：Healthy foreskin tissue samples were obtained from eight patients aged less than 30 years undergoing prepucectomy.Cultured primary human skin keratinocytes from the foreskin were stimulated with graded concentrations of TNF-α（10,50,100,150,and 200 μg/L）.Real-time PCR was performed to quantify mRNA expression of β-defensin 1,2,3 and Toll-like receptor 2,4 from the stimulated cells.RESULTS AND CONCLUSION：Compared with the control group,the expressions of β-defensin 1,2,3 and Toll-like receptor 2,4 in keratinocytes induced by TNF-α were up-regulated apparently and the strongest inducible effect was at the concentration of 150 μg/L（P〈0.05） and down-regulated again at the concentration of 200 μg/L,presenting a dose-dependent manner.Skin keratinocytes showed a marked inductive capacity to produce human β-defensin 1,2,3 and Toll-like receptor 2,4 in response to TNF-α.