过氧化氢酶和尿素酶B亚单位二价疫苗预防小鼠幽门螺杆菌感染

目的 利用人类幽门螺杆菌(H.priori)感染的小鼠模型研究过氧化氢酶和尿素酶B亚单位二价疫苗预防H.pylori感染的作用.方法 把实验动物无特定致病菌C57BL/6小鼠分成7组,分别通过灌胃方法给予过氧化氢酶和尿素酶B亚单位(各100μg)加霍乱毒素(CT)(2 μg)、过氧化氢酶(100 μg)加CT(2 μg)、尿素酶B亚单位(100 μg)加CT(2 μg)、PBS、单纯过氧化氢酶(100μg)、单纯尿素酶B亚单位(100μg)、单纯CT(2μg),共4次.2周后再用活H.pylori灌胃,再4周后处死动物.取胃粘膜行半定量细菌培养检查H. pytori情况.结果 实验各组H.pylori完全保护率分别为:过氧化氢酶和尿素酶B亚单位加CT组83.3%(20/24)、过氧化氢酶加CT组41.7%(10/24)、尿素酶B亚单位加CT组54.2%(13/24);生理盐水组、单纯过氧化氢酶、单纯尿素酶B亚单位、单纯CT组根除率均为0%.未完全保护的小鼠,疫苗组H. pylori的定植密度明显低于其它4组(P<0.05).此外,二价疫苗组的H. pylori完全保护率及定植密度较单价疫苗组均有显著性差异(P<0.05).结论 由过氧化氢酶和尿素酶B亚单位加免疫佐剂组成的二价口服疫苗较单价口服疫苗有更好的免疫预防效果.

Immunization with catalase and UreB two-valence vaccine for preventing Helicobacter pylori infection in mice

OBJECTIVE: To investigate the effects of the two-valence vaccine consisting of Helicobacter pylori (H. pylori) catalase and urease subunit UreB in preventing H. pyloriinfection in mice. METHODS: C57BL/6 mice were divided into 7 groups and immunized with intragastric administration of catalase and UreB (both 100 microg) plus cholera toxin (CT, 2 microg), catalase (100 microg) plus CT (2 microg), UreB (100 microg) plus CT (2 microg), catalase (100 microg), UreB (100 microg), CT (2 microg), or PBS, respectively, once a week for 4 consecutive weeks. Two weeks after the last immunization, all the mice were challenged by live H. pylori, and sacrificed 4 weeks after the challenge to obtain the gastric mucosa samples for detecting H. pylori using semi-quantitative bacterial culture assay. RESULTS: The total protection rate in mice immunized with the two-valence vaccine, single-valence vaccine of catalase, and single-valence vaccine of UreB was 83.3% (20/24), 41.7% (10/24) and 54.2% (13/24), respectively, and the rate in the other 4 groups were all 0. The H. pyloricolony density in mice with vaccination was significantly lower than that of other 4 groups (P<0.05). The total protection rate and H. pylori colony density differed significantly between the two-valence vaccination group and the single-valence vaccination groups (P<0.05). CONCLUSION: The two-valence vaccine consisting of catalase, UreB and adjuvant has better immunoprotective effects than the single-valence vaccines.