幽门螺杆菌黏附素适配子的筛选及其抗感染研究

The high prevalence of Gastric cancer is correlated with Helicobacter pylori (H.pylori) infection. In view of peak infection rate and increasing resistance rate of H.pylori, a novel treatment was urgently in demand, which can eliminate H.pylori for H.pylori-infected groups of antibiotics contraindication and drug-resistant strains infection. We will design a group of nucleic acid drugs to disturb the binding between H.pylori and gastric mucosal cells. Using them for treatment is both availably eliminate colonization of H.pylori and not bringing resistance. The groups of ssDNA oligonucleotide aptamers were screened to bind 7 kinds of main adhesins from H.pylori surface by SELEX respectively. Then the ability of aptamers were proved by in vitro stduy and infected animal model, that block binding between H.pylori and gastric mucosal cells and relieve the colonization-caused cells damage.The ultimate aim is that drugs-resistance H.pylori strains were eliminate from infected animal model to lay a foundation for novel anti-H.pylori drugs.

幽门螺杆菌（H.pylori）感染与胃癌的高发密切相关。鉴于H.pylori高感染率和日益升高的耐药率，亟需一种能够针抗生素使用禁忌H.pylori感染群体及对H.pylori耐药菌株感染发挥广谱抗菌作用的新型治疗手段。本研究拟设计一种以被动免疫为手段的治疗型核酸药物，以期通过干扰H.pylori与胃粘膜细胞的结合，有效清除H.pylori。项目拟运用SELEX技术以H.pylori表面7种起主要黏附作用的黏附素蛋白为靶标，筛选出与之特异性结合的一组ssDNA寡核苷酸适配子。随后通过体外细胞实验和动物感染模型验证适配子阻断H.pylori与胃黏膜上皮细胞的结合，以及缓解黏附作用诱发的细胞损伤的能力。力图最终利用筛选的适配子降低或清除H.pylori在动物感染模型胃内的定植，为进一步研发新型抗H.pylori药物奠定基础。

幽门螺杆菌（Hp）的危害及广泛传播引起了人们的广泛关注。其耐药菌株的日益流行亟待一种不产生抗生素选择性压力且毒副作用较小的新型治疗型制剂。根据Hp的感染途径中黏附作用的重要性，本研究拟针对黏附的物质基础——黏附素筛选特异性的配基，以期发挥抗Hp感染作用。本研究克隆并原核表达、纯化了Hp黏附素HpaA并运用SELEX技术筛选获得了特异性结合HpaA的适配子命名为HA6。体外实验表明HA6能够用于对新鲜胃黏膜中Hp行荧光免疫检测诊断，同时流式细胞术证明HA6通过结合HpaA显著阻断Hp与胃黏膜的侵袭。鉴于胃内特殊的环境，本研究还通过化学手段合成了尿素纳米胶囊装载并保护适配子HA6，并通过小鼠Hp感染模型验证口服方式发挥治疗Hp疗效，结果显示纳米胶囊装载的HA6能够显著减少Hp的黏附同时减轻胃黏膜的损伤。综上所述，本研究通过尿素纳米胶囊保护适配子进入胃内发挥抗Hp作用切实可行，本项目有利于为新型Hp治疗制剂的研发提供思路。