旋毛虫抗原基因Ts88原核表达及重组蛋白鉴定

目的　原核表达旋毛虫抗原基因Ts88,并对重组蛋白的抗原性进行鉴定。　方法　免疫筛选cDNA文库得到旋毛虫抗原新基因Ts88,克隆入原核表达载体pET28c(+),异丙基βD硫代半乳糖苷诱导表达。重组蛋白免疫小鼠制备免疫血清,ELISA检测抗体滴度。蛋白质印迹法检测重组蛋白的抗原性。免疫荧光试验确定Ts88蛋白在虫体的分布。　结果　经原核表达的Ts88重组蛋白,用其免疫小鼠可得到高滴度的抗体血清。蛋白质印迹法结果表明该重组蛋白能与旋毛虫病患者血清、旋毛虫病猪血清、人工感染及人工免疫兔血清反应,不与其他蠕虫病患者血清发生交叉反应 ,并能识别旋毛虫虫体天然抗原成分。免疫荧光试验显示Ts88蛋白主要分布于虫体体壁。　结论　成功制备Ts88基因的重组蛋白,证明该蛋白具有较好的抗原性

Prokaryotic Expression of an Antigen Gene of Trichinella spiralis and Identification of the Recombinant Protein

OBJECTIVE: To obtain the recombinant protein of an antigen gene Ts88 of Trichinella spiralis and identify the characteristics of the recombinant protein. METHODS: Ts88 cDNA obtained by immunoscreening the cDNA library of adult T. spiralis was subcloned into the pET-28c(+) expression vector and expressed in E. coli. Mice were immunized with the fusion protein incorporated into Freund' s adjuvant and the immune sera were collected. The titers of the Ts88 immune sera and the antigenicity of the recombinant protein were detected by ELISA and Western blotting. Immuno-fluorescence test was performed in order to confirm the distribution of Ts88 protein in the worm. RESULTS: The fragment of Ts88 gene was expressed successfully in E. coli and a highly purified fusion protein was obtained. Immunization with the recombinant protein in mice produced high titers of antibodies, which recognized some components of native antigens of soluble proteins from adult worm of T. spiralis. Western blotting analysis showed that Ts88 recombinant antigen was recognized by all the positive sera, such as the sera from infected or immunized rabbits, from infected swine and from patients of trichinosis. Immuno-fluorescence test confirmed that Ts88 protein mainly distributed in the cuticle surface of the worm. CONCLUSION: The Ts88 antigen gene from T. spiralis was successfully expressed. The recombinant protein presented antigenicity.