【摘要】 目的比较不同种族H.pylori菌株CagA蛋白羧基端结构以及诱导AGS细胞延伸、分泌IL-8能力的差异。方法 PCR扩增CagA3′端可变区DNA序列并进行测序,获得CagA3′端可变区氨基酸序列。以不同H.pylori菌株与AGS细胞孵育,观察AGS延伸细胞的百分数,测定细胞培养上清IL-8含量。结果美籍亚裔和美籍非裔菌株的CagA羧基端氨基酸第3个EPIYA前后的氨基酸序列存在明显差异。不同种族cag PAI+H.pylori导致AGS细胞延伸、分泌IL-8能力无明显差异。cag PAI+H.pylori诱导细胞延伸AGS细胞、分泌IL-8的能力明显大于cag PAI-H.pylori。结论不同种族H.pylori菌株CagA蛋白羧基端结构存在差异。H.py-lori菌株诱导AGS细胞延伸、分泌IL-8的能力与cag PAI有关。更多还原

【Abstract】 Objective To compare the structural diversity of H.pylori CagA protein C-terminal and biological activities of H.pylori on gastric epithelial cells.Methods The CagA gene 3′terminal variable region was amplified with PCR.The PCR products were sequenced.AGS cells were cocultured with H.pylori strains.Cells were examined for cellular elongation by light microscopy.IL-8 production in cell supernatant was measured by ELISA.Results The amino acid sequences surrounded the third EPIYA site varied among different ethnic strains.Cag PAI+H.pylori strains from different ethnic groups showed no different ability of inducing IL-8 production and cellular elongation.Cag PAI+H.pylori strains showed higher level ability of inducing IL-8 production and cellular elongation than Cag PAI-H.pylori strains.Conclusion The amino acid sequences of cagA gene 3′terminal variable region varied among different ethnic strains.Ability of H.pylori inducing IL-8 production and cellular elongation may depend on cag PAI.更多还原