幽门螺杆菌cagⅡ对胃上皮细胞IL-8基因转录的影响及机制  

The effects of cag Ⅱ of Helicobacter pylori on the transcription of IL- 8 in gastric epithelial cells and mechanisms

作　　者：李淑德[1] 许国铭[1] 李兆申[1] Crabtree JE Neelam B 

机构地区：[1]第二军医大学长海医院,上海市200433 [2]英国LeedsSt.James医院分子医学部

出　　处：《中华消化杂志》2000年第4期230-233,共4页Chinese Journal of Digestion

基　　金：欧共体资助课题!(IC18CT95 0024)

摘　　要：目的　探讨HpcagⅡ对胃上皮细胞IL 8基因转录的影响及信号传导机制。 方法　构建cagⅡ基因位点缺失Hp突变株及带有IL 8报告基因的人胃癌细胞系L5F11,用液体闪烁计数仪测定荧光素酶 (IL 8转录 )活性 ,用ELISA法测定IL 8蛋白浓度。结果　所有Hp突变株诱导荧光素酶活性与IL 8蛋白浓度较亲代菌株 2 6 6 95均降低 [(0 .13± 0 .0 1)× 10 6cpm比 (0 .5 9± 0 .0 5 )× 10 6cpm (P <0 .0 1) ;(0 .73± 0 .13)ng/ml比 (2 .2 2± 0 .6 5 )ng/ml,(P <0 .0 5 ) ]。PTK抑制剂herbimycinA不仅抑制Hp诱导的荧光素酶活性 [(0 .71± 0 .18)× 10 6cpm比 (1.5 1±0 .2 3)× 10 6cpm ,(P <0 .0 5 ) ],而且抑制IL 8蛋白表达 [(0 .83± 0 .41)ng/ml比 (3.2 2± 0 .5 9)ng/ml,(P <0 .0 5 ) ],但herbimycinA对TNFα诱导的荧光素酶活性及IL 8蛋白表达均无影响 (P均 >0 .0 5 ) ;PKA抑制剂H7抑制TNFα诱导的荧光素酶活性 [(0 .74± 0 .16 )× 10 6cpm比 (2 .6 2± 0 .2 6 )× 10 6cpm ,(P <0 .0 0 1) ]及IL 8蛋白表达 [(1.45±0 .38)ng/ml比 (4 .12± 0 .43)ng/ml,(P <0 .0 1) ],而对Hp诱导的荧光素酶活性无影响 (P >0 .0 5 )。 结论　HpcagⅡ中的多个基因能够调节胃上皮细胞IL 8基因转录 。Objective To study the effect of the cag Ⅱ of H.pylori on the transcription of IL 8 and to explore the mechanisms of signal transduction in the transcription of IL 8 induced by H. pylori in gastric epithelial cells. Methods The constructed L5F11 cells were co cultured with different isogenic mutants of H.pylori . The transcription and translation of IL 8 were indicated by the luciferase activity and IL 8 protein respectively. Results The ability to induce the luciferase and IL 8 protein by the mutant strains were much lower than that of by parent strain 26695 [(0.13±0.01)×10 6 cpm vs (0.59±0.05)×10 6 cpm, P <0.01; (0.73±0.13) ng/ml vs (2.22±0.65) ng/ml, P <0.05; respectively)]. Exposure of L5F11 cells to herbimycin A reduced both H.pylori induced luciferase activity [(0.71±0.18)×10 6 cpm vs (1.51±0.23)×10 6 cpm, P <0.05)] and IL 8 protein production [(0.83±0.41) ng/ml vs (3.22±0.59) ng/ml but it had no effect on TNFα induced IL 8 transcription ( P >0.05) and IL 8 protein production ( P > 0.05). H7 inhibited TNFα induced luciferase [(0.74±0.16)×10 6 cpm vs (2.62±0.26)×10 6 cpm, P < 0.001) and IL 8 protein production (1.45±0.38) ng/ml vs (4.12±0.43) ng/ml, P < 0.01)] but had no significant effect on H.pylori induced luciferase activity ( P >0.05). Conclusions This results showed that multiple genes in the cag Ⅱ locus play an important role in the transcription of IL 8 in L5F11 gastric epithelial cells, and moreover the transcription of IL 8 gene induced by H.pylori is mainly mediated by the protein tyrosine kinase.

关 键 词：幽门螺杆菌 cagⅡ 胃上皮细胞 白细胞介素-8 

分 类 号：R573[医药卫生—消化系统]