重组减毒沙门菌尿素酶B亚单位和过氧化氢酶疫苗治疗幽门螺杆菌感染的实验研究

Therapeutic vaccination against Helicobacter pylori infection with recombinant attenuated Salmonella typhimurium urease B snbunit and catalase in mice

目的 利用人类幽门螺杆菌 (Hp)感染的小鼠模型研究重组减毒沙门菌尿素酶B亚单位和过氧化氢酶疫苗在治疗Hp感染中的作用。 方法 将 30只二级C5 7BL/ 6小鼠随机分成 3组 ,通过灌胃方法每只小鼠均用活力良好的Hp菌株隔日攻击 2次。在第二次Hp攻击后 4周 ,分别给予重组减毒沙门菌尿素酶B亚单位疫苗 (A组 )、过氧化氢酶疫苗 (B组 )和生理盐水 (C组 )灌胃 1次 ,4周后处死动物 ,取胃组织分别行尿素酶试验、改良Giemsa染色及定量细菌培养 ,观察Hp定植情况。行HE染色观察胃黏膜组织炎症情况。取脾组织行淋巴细胞增殖试验。结果 C组小鼠Hp定植密度为 1.92× 10 6CFU/g胃组织 ,A组和B组小鼠分别为 1.5 8× 10 5CFU/g和 4 .88× 10 5CFU/g胃组织 ,两个治疗组的定植密度明显降低 (P <0 .0 5 )。治疗组与对照组胃黏膜均无明显炎症反应。治疗组脾淋巴细胞增殖试验阳性。结论 重组减毒沙门菌尿素酶B亚单位疫苗和过氧化氢酶疫苗对Hp感染有治疗作用。

Objective To investigate the effects of oral recombinant attenuated Salmonella ophimurium urease B subunit and catalase in the treatmeat of H.pylori infection in a H.pylori infected mouse model. Methods Thirty C57BL/6 mice were randomized into three groups and challenged twice by oral administration of H.pylori in three days. Four weeks after the second challenge, the mice were immunized by oral administration of recombinant attenuated Salmonella typhimurium urease B subunit (group A), recombinant attenuated Salmonella typhimurium catalase (group B), or saline (group C) respectively, and all mice were sacrificed 4 weeks after the immunization. The stomachs were collected for rapid urease test, modified Giemsa stain and quantitative culture to observe the gastric H.pylori densities, and HE stain was performed to assess the presence of inflammation. Lymph cells from the spleens were served for lymphoproliferation assay. Results Gastric H.pylori densities of group A, B and C were 1.58×10 5 CFU/g, 4.88×10 5 CFU/g and 1.92×10 6CFU/g respectively. H.pylori densities of therapeutic groups were significantly decreased ( P <0.05). No significant inflammation was found in all groups of mice. The lymphoproliferation assay of group A and B was positive. Conclusion The oral recombinant attenuated Salmonella typhimurium urease B subunit and catalase vaccine are effective in reducing the densities of H.pylori colonizition.