布氏杆菌S2疫苗株GL_0002181基因的原核表达

Prokaryotic expression of GL_0002181 gene from Brucella vaccine strain S2

为了鉴别羊种布氏杆菌自然感染和S2疫苗(猪种)免疫羊,选用布氏杆菌S2疫苗株进行了全基因组测序,预测出的编码基因与已公布的布氏杆菌基因组数据库比对分析,找出S2特有基因GL_0002181,对GL_0002181基因进行原核表达及免疫原性验证,同时用BP26蛋白作为对照组。Western blot结果显示:以S2疫苗免疫绵羊血清作为检测抗体,重组菌BL21(pETGL_0002181)、BL21(pETBP26)与BL21(DE3)空菌比较,分别在31 ku、32 ku处出现了特异性条带,说明重组蛋白能够与S2免疫血清中的抗体发生特异性反应,具有较好的免疫原性;而重组表达菌BL21(pETGL_0002181)菌体蛋白与自然感染血清不反应,重组蛋白BP26与自然感染血清反应,说明GL_0002181基因在S2疫苗株中存在,在羊种自然流行株中不存在。结果表明:GL_0002181抗原可用于布氏杆菌S2疫苗免疫与羊种布氏杆菌自然感染鉴别诊断,为布氏杆菌病有效诊断提供理论依据。

In order to distinguish Brucella vaccine strain S2 from field strains of Brucella melitensis,gene GL_0002181 encoding an immunogenic protein was screened out for expression and immunogenicity verification. BP26 gene served as control group. The western blot results showed that there was two main recombinant protein bands GL_0002181 and BP26 with molecular weight of 31 ku and 32 ku,respectively. It showed that recombinant protein GL_0002181 could react specifically with serum antibodies against S2,but not react with the serum of sheep naturally infected with B. melitensis. BP26 could react with immune serum as well as the serum of natural infection. These results indicate that GL_0002181 antigen can be used for differential diagnosis between vaccine immunity and natural infection of Brucella.