问号钩体lipL32/1-lipL41/2融合基因的构建及其表达产物免疫性的鉴定(英文)

Construction of the fusion gene lipL32/1-lipL41/2 from Leptospira interrogans and the immuno-reactivity of its expressed products

目的构建问号钩端螺旋体(简称钩体)lipL32/1-lipL41/2融合基因及其原核表达系统并鉴定其表达产物的免疫性。方法采用连接引物PCR构建lipL32/1-lipL41/2融合基因,常规方法构建其原核表达系统。采用SDS-PAGE和BioRad凝胶图象分析系统检测目的重组蛋白rLipL32/1-LipL41/2表达情况。采用Western blot鉴定rLipL32/1-LipL41/2的免疫反应性。采用ELISA检测228例钩体病人血清中lipL32/1、lipL41/2基因和lipL32/1-lipL41/2融合基因表达产物的抗体。结果 lipL32/1-lipL41/2融合基因核苷酸和氨基酸序列与报道的相关序列相似性分别为99 .9 %和99 .8 %。rLi-pL32/1-LipL41/2表达量约为细菌总蛋白的10 %。rLipL32/1和rLipL41/2兔抗血清均能识别并与rLipL32/1-LipL41/2结合。97 .4 %、78 .5 %和99 .1 %病人血清rLipL32/1、rLipL41/2和rLipL32/1-LipL41/2抗体阳性。结论本研究成功地构建了问号钩体lipL32/1-lipL41/2融合基因及其原核表达系统,rLipL32/1-LipL41/2不仅同时具有两个单一重组抗原的免疫反应性,且能提高钩体病人血清中抗体检测阳性率,可作为研制钩体属特异性基因工程疫苗或检测试剂盒的候选抗原。

In the present study, the fusion gene lipL32/1-lipL41/2 from Leptospira interrogans was constructed by using PCR with linking primers, expressed in prokaryotic expression system. And the immuno-reactivity of its expressed product was determined. Meanwhile, SDS-PAGE and BioRad agarose image analyzer system was used to examine the expression output of the target recombinant protein rLipL32/1-LipL41/2, and the immune-reactivity of this recombinant protein was identified by Western blot assay. ELISA was used to detect the level of antibodies against the recombinant proteins in sera of patients with leptospirosis. It was demonstrated that the percentages of similarity in nucleotide and the putative amino acid sequences of the fusion gene lipL32/1-lipL41/2 with the corresponding sequences previously reported were 99.9% and 98.9% respectively. The expression output of the target recombinant protein was approximately 10% of the total bacterial proteins. Both the rabbit antisera against rLipL32/1 and rLip41/2 could recognize and combine to the recombinant fusion protein rLip32/ 1-Lip41/2 as weft. The positive rates of antibodies in 228 leptospirosis patients with the recombinant proteins rLip32/1, rLip41/2 and rLip32/1-Lip41.2 were 97.4%, 78.5% and 99.1% respectively. The results of the present study leads to the conclusion that the fusion gene lipL32/1-lipL41/3 with its prokaryotic expression system is successively constructed and the expressed recombinant protein shows excellent immuno-reactivity, thus suggesting that it may be used as the antigenic candidate for the development of the leptospiral genus-specific engineering vaccine and for the preparation of diagnostic kits.