幽门螺杆菌表位疫苗的设计、构建、表达及其免疫原性研究

目的 设计幽门螺杆菌（Hp）的表位疫苗并对其免疫原性进行研究。方法 将Hp的尿素酶B亚单位的三个Th表位及一个B细胞表位串联，表位之间用两个赖氨酸（KK）间隔，合成全基因，克隆到pET-22b载体上，在大肠杆菌B121（DE3）中表达；表达的重组蛋白经鉴定纯化后皮下免疫Balb／c小鼠，检测细胞免疫应答及体液免疫应答。结果 克隆表达的重组表位疫苗蛋白纯化后纯度达到95％，经N端测序证实为设计的表位疫苗蛋白，Th表位多肽（U546-561、U229-244、U237-251）、表位疫苗蛋白及rUreB均能够刺激表位疫苗致敏的小鼠淋巴细胞增殖（SI〉2），并且此疫苗能够刺激机体产生特异性抗体。结论 本研究中表位疫苗的设计方法能够使疫苗中包含的四个表位均发挥功能，并且具有较强的免疫原性，为研究Hp预防性和治疗性疫苗提供实验基础。

Design, construction, expression, and immunogenicity of Helicobacter pylori epitope vaccine

Objective To design the Helicobacter pylori epitope vaccine and study its immunogenicity in Balb/c mice. Methods The epigene was designed and synthesized, containing three Th cell epitopes and one B cell epitope that come from urease B subunit. The epigene was cloned into expression vector pET-22b(+) and expressed in Escherichia coli BL21(DE3). Balb/c mice were immunized subcutaneously by the purified protein and then the cellular and humoral immune response was detected. Results Recombinant protein was successfully expressed in Escherichia coli BL21 and could elicit strong cellular and humoral immune response. Conclusion The method of designing the epitope vaccine is proved to be successful and the expressed protein may be a potential candidate of therapeutic and preventive vaccine of Helicobacter pylori.