幽门螺杆菌黏附定植在感染发病中的作用机制研究

Study on the mechanism of Helicobacter pylori adhesion colonization in the pathogenesis of infection

幽门螺杆菌(Helicobacter pylori,Hp)致病的前提是能够定植于宿主胃内,而黏附是定植的关键。Hp的黏附定植过程首先是通过鞭毛介导的运动向上皮细胞移动,随后通过菌毛、黏附素-受体相互作用后黏附于宿主细胞,接着释放毒素引起菌体周围组织损伤。其中起到中和作用的是脲酶的表达及活化产生活性脲酶,随后脲酶分解尿素,改变了局部酸碱环境,有利于黏附定植;在此基础上,Hp再借助鞭毛顺利穿过胃黏液层到达黏膜表面。为了避免表面上皮细胞和黏液层的脱落而被清除,Hp会分泌黏附素,如HapA、BabA、SabA和AlpA等,与宿主细胞上的受体相互作用,使细菌能够长期定植于胃黏膜表面,损伤宿主组织,导致一系列胃肠疾病,甚至胃癌或胃淋巴瘤的发生。

It is the premise of pathogenesis that Helicobacter pylori(Hp)can colonize in the stomach of the host,and adhesion is the key to colonization.Hp first moves to epithelial cells through flagella mediated movement for adhesion and colonization,then adheres to host cells through the interaction between pili,adhesins and receptors,and then causes tissue damage through toxin release.The expression and activation of urease produce active urease,which plays the role of neu-tralization by decomposing urea,so as to change the local acid and alkali environment for better adhesion and colonization;On this basis,with the help of flagella,Hp passes through the gastric mucus layer and successfully reaches the mucosal surface.In order to avoid being removed with the shedding of surface epithelial cells and mucous layer,Hp secretes ad-hesins,such as HapA,BabA,SabA and AlpA,which interact with the receptors on the host cells,making bacteria colonize the surface of the gastric mucosa for a long time.It causes damage to the host tissue in this way,and eventually results in a series of gastrointestinal diseases,even gastric cancer or gastric lymphoma.