摘要
目的:研究在痢疾志贺菌F2a-12脂多糖刺激下,大鼠小肠上皮内淋巴细胞(IEL)对人结肠癌上皮细胞系Caco-2屏障功能的影响。方法:新鲜分离的大鼠小肠IEL与Caco-2共培养,并用F2a-12LPS刺激共培养细胞。通过检测短路电流、紧密连接相关蛋白表达及透射电镜来反映上皮屏障功能的变化。结果:共培养后跨上皮电阻增加,但在LPS刺激后显著降低;紧密连接相关蛋白ZO-2mRNA表达在共培养后增加,LPS刺激后共培养细胞ZO-1mRNA表达显著下降;透射电镜下可见共培养后细胞间紧密连接显著增强,但在LPS刺激后共培养细胞间的连接几乎消失。首次在电镜下发现上皮细胞与IEL间有连接样结构的存在,为其相互作用提供了形态学的证据。结论:IEL对上皮屏障功能具双向调节作用,在生理状态下增强,但在感染信号存在时降低。
Objective： To examine modulation of epithelial barrier function of human colonic epithelial cell line Caco-2 by intestinal intraepithelial lymphocyte （IEL） in response to challenge of Shigella F2a-12 LPS. Methods： Freshly isolated rat IEL were co-cultured with Caco-2, then exposed to Shigella F2a-12 LPS. Barrier function of the epithelial monolayer was measured by the short-circuit current technique （Isc） and examined by transmission electron microscopy （TEM） and mRNA expression of tight junction associated proteins ZO-1 and ZO-2. Results： The transepithelial resistance of the epithelial monolayers increased when co-cuhured with IEL, while decreased significandy after exposed to Shigella F2a-12 LPS. mRNA expression of tight junction associated protein ZO-2 increased after co-culture, while mRNA expression of ZO-1 decreased after co-cultured and challenged by LPS. Tight junction was enhanced significandy after co-culture under TEM, while almost disappeared when challenged by LPS. Junction-like structure was also found between IEL and Caco-2 under TEM for the first time, providing the first structure evidence for their interaction. Conclusion： The results suggest that IEL influence epithelial barrier function in two ways： enhancing the barrier function under physiological condition and reducing while under the challenge of infectious signals.
出处
《军事医学科学院院刊》
CSCD
北大核心
2005年第4期301-304,共4页
Bulletin of the Academy of Military Medical Sciences
关键词
肠黏膜上皮细胞
上皮内淋巴细胞
共培养
跨上皮电阻
紧密连接
屏障功能
intestinal epithelial cell
intraepithelial lymphocyte
co-culture
transepithelial electrical resistance
tight junction
barrier function
