Core 3 O-型糖链参与大肠杆菌对肠上皮细胞黏附和侵袭的影响  

The involvement of Core 3 O-glycans in the adhesion and invasion of Escherichia coli to intestinal epithelial cells

作　　者：刘韵 叶钧 LIU Yun;YE Jun(Department of Gastroenterology,the First Affiliated Hospital of Army Medical University,Chongqing 400038,China;Department of Gastroenterology,No.958 Hospital of Liberation Army,Chongqing 400020,China)

机构地区：[1]陆军军医大学第一附属医院消化内科,重庆400038 [2]陆军第九五八医院消化科,重庆400020

出　　处：《中国医药科学》2022年第3期37-41,共5页China Medicine And Pharmacy

摘　　要：目的探讨Core 3 O-型糖链对大肠杆菌黏附和侵袭肠上皮细胞的影响。方法通过慢病毒转染技术,获得β-1,3-N-乙酰氨基葡萄糖转移酶6(β3gnT6)稳定过表达的肠上皮细胞株(β3gnT6/HT-29和β3gnT6/LS174T)及其对照细胞株(Ctr/HT-29和Ctr/LS174T)。上述细胞株与肠致病性大肠杆菌(EPEC)和肠出血性大肠杆菌(EHEC O157∶H7)共培养,采用细菌梯度稀释克隆计数和荧光显微镜直接观察法,计数黏附于细胞表面的细菌数;上述细胞株与侵袭性大肠杆菌(EIEC)共培养2 h,通过庆大霉素杀灭黏附于细胞表面的细菌,再采用细菌梯度稀释克隆计数法,计数侵袭入细胞内细菌数。最后通过测定单层细胞跨膜电阻值(TEER),评价Core 3 O-型糖链对肠上皮细胞屏障功能的影响。结果细菌克隆计数和荧光显微镜直接观察法均显示,黏附于β3gnT6/HT-29和β3gnT6/LS174T细胞株的EPEC和EHEC O157∶H7少于其对照细胞(P<0.01或P<0.05);侵袭入β3gnT6/HT-29和β3gnT6/LS174T细胞株的EIEC高于其对照细胞(P<0.01或P<0.05);在EPEC或EHEC O157∶H7感染条件下,不同时间点上均呈现出β3gnT6/HT-29和β3gnT6/LS174T细胞株的TEER下降值高于其对照细胞(P<0.01或P<0.05)。结论促进肠上皮细胞Core 3 O-型糖链表达将抑制大肠杆菌黏附于肠上皮细胞,同时对大肠杆菌侵袭易感。Objective To investigate the effects of Core 3 O-glycans on the adhesion and invasion of Escherichia coli to intestinal epithelial cells.Methods Intestinal epithelial cell lines(β3gnT6/HT-29 andβ3gnT6/LS174T)with overexpressed stableβ-1,3-N-acetylglucosaminyltransferase 6(β3gnT6)and their control cell lines(Ctr/HT-29 and Ctr/LS174T)were obtained by lentiviral transfection technique.The above cell lines were co-cultured with enteropathogenic Escherichia coli(EPEC)and enterohemorrhagic Escherichia coli(EHEC O157∶H7),and the number of bacteria adhering to the cell surface was counted by bacterial cloning counting method based on gradient dilution and direct observation by fluorescence microscopy.The above cell lines were co-cultured with enteroinvasive Escherichia coli(EIEC)for 2 h.The bacteria adhering to the cell surface were killed by gentamicin before the number of bacteria invading the cells was counted by the bacterial cloning counting method based on gradient dilution.Finally,the effect of Core 3 O-glycans on the barrier function of intestinal epithelial cells was evaluated by measuring the trans-epithelial electric resistance(TEER)of monolayer cells.Results Both bacterial cloning counting method and direct fluorescence microscopy showed that the numbers of EPEC and EHEC O157∶H7 adhering toβ3gnT6/HT-29 andβ3gnT6/LS174T cell lines were less than those of their control cells(P<0.01 or P<0.05).The number of EIEC invading intoβ3gnT6/HT-29 andβ3gnT6/LS174T cell lines was higher than that of their control cells(P<0.01 or P<0.05).Under EPEC or EHEC O157∶H7 infection conditions,bothβ3gnT6/HT-29 andβ3gnT6/LS174T cell lines showed higher decreasing values of TEER than their control cells at different time points(P<0.01 or P<0.05).Conclusion Promoting the expression of Core 3 O-glycans in intestinal epithelial cells will inhibit Escherichia coli from adhering to intestinal epithelial cells,and is susce ptible to Escherichia coli invasion.

关 键 词：Core 3 O-型糖链 黏附 侵袭 TEER 

分 类 号：R378.2[医药卫生—病原生物学]