多房棘球蚴LDH基因的克隆表达及免疫原性研究

Cloning and prokaryotic expression of LDH gene in Echinococcus multilocularis and immunogenicity research of the recombinant protein

目的克隆表达青海省多房棘球蚴(Echinococcus multilocularis,Em)乳酸脱氢酶(lactate dehydrogenase,LDH)基因,鉴定EmLDH重组蛋白的免疫原性,初步评价其免疫诊断价值。方法采用RT-PCR方法克隆EmLDH基因,将其连接入pET15b表达载体中,构建重组表达质粒pET15b-EmLDH,转化至E.coli Rosetta(DE3)感受态细胞进行诱导表达。通过SDS-PAGE检测重组蛋白的表达形式,Ni-IDA树脂亲和层析纯化重组蛋白。通过Western blotting法鉴定EmLDH重组蛋白的免疫原性,ELISA法检测泡型包虫病患者(57例)、囊型包虫病患者(33例)和正常人(50例)血清,初步评价EmLDH重组蛋白的免疫诊断效果。结果成功克隆了EmLDH基因并表达纯化出相应的重组蛋白。Western blotting结果显示,EmLDH重组蛋白可被泡型和囊型包虫病患者血清识别,而不被正常人血清识别。ELISA结果显示,EmLDH重组蛋白对泡型和囊型包虫病患者血清的诊断敏感性分别为84.21%和84.85%。结论 EmLDH重组蛋白具有较高的免疫原性,对包虫病具有较好的免疫诊断价值。

The present study aimed to clone and express the EmLDH gene of Echinococcus multilocularis in Qinghai Province,identifying immunogenicity of EmLDH recombinant protein and evaluating its immune diagnostic value preliminarily.EmLDH genes were cloned by RT-PCR technology and linked into pET15 bvector.Recombinant expression pET15b-EmLDH vectors were constructed and transformed into E.coli Rosetta(DE3)competent cells.Recombinant proteins were induced and expressed.Expression forms of recombinant proteins were detected by SDS-PAGE.Recombinant proteins were purified by affinity chromatography of Ni-IDA resin.Immunogenicity of recombinant proteins was identified by Western blotting.Serum samples from patients with alveolar echinococcosis(57 cases),cystic echinococcosis(33 cases),and healthy persons(50 cases)were examined by ELISA,which evaluated preliminarily immune diagnosis effect of EmLDH recombinant proteins.Results showed that EmLDH gene was cloned successfully and the recombinant proteins were expressed and purified.Results of Western blotting showed EmLDH recombinant proteins were recognised by serum samples from patients with alveolar echinococcosis and cystic echinococcosis,but not by serum samples from healthy persons.Results of ELISA showed that diagnostic sensitivities of EmLDH recombinant protein reacted with serum samples from patients with alveolar echinococcosis and cystic echinococcosis were 84.21% and 84.85% respectively.EmLDH recombinant proteins of Echinococcus multilocularis have high immunogenicity and good immune diagnostic value for echinococcosis.