摘要
目的 克隆和表达梅毒螺旋体Tp0319基因,并对其表达产物进行免疫活性分析.方法 挑选并克隆出Tp0319免疫优势区基因,构建原核表达载体 诱导表达并纯化重组蛋白,用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)和Western印迹法鉴定 用纯化的重组蛋白免疫新西兰兔 间接ELISA法检测梅毒螺旋体参考血清及临床标本.结果 成功构建原核表达载体pQE32/Tp03 19 高效表达和纯化出一相对分子质量约30 000的重组蛋白.用重组蛋白免疫新西兰兔,能刺激其产生高水平抗体滴度.Western印迹证明其能与梅毒患者血清发生特异性反应,阴性对照菌未见目的 表达条带.间接ELISA法检测80份梅毒螺旋体参考血清(阴性、阳性各40份),阳性和阴性结果的符合率均为100%.检测200份临床梅毒血清标本及200份正常人血清,结果与梅毒螺旋体明胶凝集试验相比,灵敏度和特异度分别为92.6%和100%,符合率为96%.结论 制备的Tp0319重组蛋白具有良好的免疫活性,为进一步研究其在梅毒血清学诊断中的应用奠定一定的基础.
Objective To clone, express Tp0319 gene from Treponemapallidum (T. pallidum), and to assess the immunocompetence of recombinant protein. Methods The immuno-dominant region of Tp0319gene was chosen by computer analysis, amplified from T. pallidum complete genome by PCR, subcloned into the expression vector pQE32 to construct a recombinant plasmid, pQE32/Tp0319, which was then expressed in E. coli M15. The recombinant protein was purified with Ni-NTA affinity chromatography, and identified by using sodium dodecyl sulfate polyacrylamide gel electropheresis (SDS-PAGE) and Western blot. New Zealand rabbits were immunized with the recombinant protein, and the titer of anti-Tp0319 antibodies in sera from immunized rabbits were measured with indirect ELISA. Also, indirect ELISA with the recombinant Tp0319 as coating antigen was performed to detect the anti-Tp0319 antibody in sera from 200 normal human controls and 200 patients with syphilis. Results The prokaryotic expression vector pQE32/Tp0319 was constructed successfully, and the recombinant protein Tp0319 with a molecular weight of about 30 000 was attained. Specific humoral response was elicited by the recombinant protein in New Zealand rabbits and the specific antibody titer was more than 1: 10 240 after immunization for 3 times. Western blot proved that the recombinant protein could specifically react with anti-T. pallidum IgG antibody-positive sera. Indirect ELISA was successfully developed with the recombinant Tp0319, and detected antibodies to T. pallidum in control sera with a sensitivity and specificity of 100% (40/40), respectively. Compared with T. pallidum particle agglutination (TPPA) assay, the sensitivity and specificity of the indirect ELISA were 92.6% and 100%, respectively, in the detection of T. pallidum in sera from patients and controls, and the concordance between the indirect ELISA and TPPA was 96%. Conclusions The prepared recombinant protein shows a satisfactory immunocompetence, which may lay a foundation for its further application in the serodiagnosis of syphilis.
出处
《中华皮肤科杂志》
CAS
CSCD
北大核心
2010年第5期332-335,共4页
Chinese Journal of Dermatology
基金
湖南省教育厅基金(07C626)
关键词
密螺旋体
苍白
重组蛋白质类
免疫活性
Treponema pallidum Recombinant proteins Immunocompetence