幽门螺杆菌尿素酶B基因的克隆、表达及免疫原性研究

Cloning, expression andimmunogenic of Hp UreB gene

目的应用基因工程方法构建表达幽门螺杆菌尿素酶Ｂ亚单位（ＵｒｅＢ）的菌株．方法用ＰＣＲ方法从幽门螺杆菌染色体ＤＮＡ上扩增出ＵｒｅＢ基因片段，将其克隆至ｐＳＫ（＋）质粒上，然后插入原核表达载体ｐＥＴ２２ｂ（＋）中，在大肠杆菌ＢＬ２１（ＤＥ３）中表达．结果经测序ＵｒｅＢ片段有１７０７ｂｐ组成，为编码５６９个氨基酸残基的多肽．ＳＤＳＰＡＧＥ和免疫印迹分析检测发现，ＵｒｅＢ基因表达的蛋白质分子质量为６５０００Ｕ，并证实该重组蛋白质可以被幽门螺杆菌感染阳性患者的血清所识别，同时将其免疫小鼠可刺激机体产生抗该重组蛋白质的抗体．结论重组的ＵｒｅＢ可以作为一种有效的蛋白质疫苗用于幽门螺杆菌感染的预防和治疗．

AIM To construct a recombinant strain which could express antigen of UreB subunit from Helicobacter pylori. METHODS The gene encoding the structural B subunit of H. pylori urease was amplified from H. pylori chromosomal DNA by PCR. The gene was inserted in the prokaryotic expression vector pET22b(+), and then was transformed into the BL21(DE3) E.coli strain, expressed UreB recombinant protein. RESULTS UreB fragments were composed of 1707 base pairs, which were encoded polypeptides of 569 amino acid residues. Western blot analysis of UreB recombinant protein showed that it can be specifically recognized by the serum of H.pyloriinfected patients, and can also be recognized by the serum of immunized Balb/c mice with UreB itself. CONCLUSION UreB may be an effective protein vaccine for prevention and treatment of the infection of H.pylori.