幽门螺杆菌CagA的序列差异对细胞形态的影响  

Effect of CagA sequence difference of Helicobacter pylori on cell morphology

作　　者：曾晓燕 全欣莹 李雷蕾[1] 贾岑岑 廖永慧 谢渊[1] 赵艳[1] 周建奖[1] ZENG Xiao-yan;QUAN Xin-ying;LI Lei-lei;JIA Cen-cen;LIAO Yong-hui;XIE-Yuan;ZHAO Yan;ZHOU Jian-jiang(Key Laboratory of Endemic and Ethnic Diseases,Ministry of Education&Key Laboratory of Medical Molecular Biology of Guizhou Province,Guizhou Medical University,Guiyang 550004,China)

机构地区：[1]贵州医科大学地方病与少数民族疾病教育部重点实验室贵州省医学分子生物学重点实验室,贵州贵阳550004

出　　处：《中国病原生物学杂志》2022年第5期537-541,共5页Journal of Pathogen Biology

基　　金：国家自然科学基金项目(No.32160166,31760328);贵州省科技计划项目[黔科合支撑(2020)4Y026号,黔科合基础(2020)1Z010,黔科合基础(2020)1Y333]。

摘　　要：目的比较幽门螺杆菌(Helicobacter pylori,Hp)感染过程中不同细胞毒素相关基因A(cytotoxin-associated gene A,CagA)序列对胃上皮癌细胞株AGS形态的影响,探讨CagA序列的结构差异。方法将含不同CagA序列的4株东亚株、3株西方株、1株cagA基因敲除株和1株CagA C端缺失株的Hp以感染复数30∶1分别感染AGS细胞6 h和7 d,观察不同时间点的细胞形态变化。以未感染及煮沸10 min的Hp感染AGS细胞为空白对照及阴性对照。从GenBank数据库收集150条cagA基因序列,用MEGA7.0软件进行聚类分析。结果cagA基因敲除株和cagA基因C端缺失株Hp感染AGS细胞6 h均未出现明显的细胞形态改变,其它7株(cagA基因完整)感染细胞后均出现明显的蜂鸟样表型的形态改变。将9株Hp煮沸10 min灭活后感染的细胞也未出现明显的形态改变。Hp持续感染7 d后,只有3株西方株和1株东亚株感染的细胞呈现蜂鸟样表型,另3株带CagA的EPIYA基序变异的东亚株未发生细胞形变。聚类分析显示,多株起源于东亚国家日本、中国和韩国的Hp聚类于西方株,且西方株CagA中EPIYA基序更容易发生变异。结论Hp西方株在中国和其它东亚国家普遍流行,其CagA比东亚株的CagA有更强的致细胞形变能力和更多的EPIYA基序变异,完整的CagA序列是诱导细胞形变的主要因素。这些数据对深入研究Hp不同基因型的致病能力有重要意义。Objective To compare the effect of cytotoxin-associated gene A(CagA)sequence differences on the morphology of gastric epithelial cancer cell line AGS cells during Helicobacter pylori(Hp)infection and analyze the structural differences of CagA sequences.Methods AGS cells were infected with Hp that contained different CagA sequences,including 4 East Asian strains,3 Western strains,1 cagA knockout strain,and 1 cagA c-terminal deleted strain,with a multiplicity of infection of 30,and then the cell morphology was observed at 6 hours and 7 days after infection.AGS cells alone and AGS cells infected with Hp boiled for 10 min were used as blank and negative controls.Subsequently,the 150 cagA sequences collected from the GenBank database were clustered with MEGA7.0 software.Results The significant changes in cell morphology of AGS cells infected with the cagA knockout strain and cagA C-terminal deleted strain were not detected,while AGS cells infected with other 7 strains containing complete cagA sequences exhibited the hummingbird phenotype at 6 hours after infection.Furthermore,the morphology of AGS cells infected with 9 Hp strains boiled for 10 min did also not change significantly.After 7 days of persistent infection with Hp,AGS cells infected with 3 Western strains and 1 East Asian strain showed the hummingbird phenotype,while the infection of AGS cells with other 3 East Asian strains carrying the mutated EPIYA motif in CagA did not cause any significant changes in cell morphology.Cluster analysis showed that many Hp strains originating from East Asian countries,including Japan,China,and Korea,were clustered into Western strains,and the EPIYA motif in CagA of Western strains was more prone to variations.Conclusion The western strains of Hp are prevalent in China and other East Asian countries,and CagA of these strains has a stronger ability to cause cell morphologic changes and more variations in EPIYA motifs than CagA of East Asian strains.The complete CagA sequences are a key factor for inducing cell morphological

关 键 词：幽门螺杆菌 CAGA 聚类分析 细胞形态学 

分 类 号：R378.91[医药卫生—病原生物学]