重组Calpain蛋白诱导抗体产生及检测日本血吸虫感染的研究

目的 研究在大肠杆菌中表达的日本血吸虫Calpain蛋白的免疫原性及其在日本血吸虫病诊断上的应用。方 法用重组Calpain蛋白免疫BALB／c小鼠，ELISA法测定特异性IgG抗体的动态变化及其IgG亚型(IgG1，IgG2a，IgG2b，IgG3)产生特征；同时用重组Calpain蛋白作为诊断抗原，粪检血吸虫病阳性患者血清作为一抗，肝吸虫阳性患者血清作为考核交叉反应血清。结果 重组Calpain抗原免疫小鼠后，产生了一个极高的抗Calpain特异性抗体，免疫4周IgG类抗体达到高峰，与对照组鼠相比较免疫鼠血清中IgG1，IgG2a，IgG2b特异性抗体也显著上升；Calpain重组抗原血清检测日本血吸虫和粪检的符合率为100％，粪检阳性EPG低的个体抗Calpain抗体滴度高，EPG高的患者抗Calpain抗体滴度反而低，与肝吸虫的交叉反应率为37％。结论 日本血吸虫Calpain是一个具有免疫原性的蛋白，能够激发宿主产生高水平的免疫球蛋白，能够敏感地测定日本血吸虫的感染，提示Calpain可以发展成为日本血吸虫病的诊断抗原和日本血吸虫疫苗候选分子。

Recombinant protein of Schistosoma japonicum calpain induced antibody production and detection of schistosoma infection

Objective To study the immunogenicity of recombinant Schistosoma japonicum (S japonicum) calpain and its application in the detection of Schistosome infection Methods BALB/c mice were immunized with recombinant calpain,IgG antibodies and its subclass (IgG1,IgG2 a,IgG2 b,IgG3) were detected with ELISA,and calpain recombinant protein was used as diagnostic antigen in the detection of antibody against S japonicum form patients The sera from patients with Clonorchis sinensis were used as cross-reaction control Results Specific antibody reached its highest level,IgG1,IgG2 a,IgG2 b significantly increased in the sera of immunized mice 4 weeks after immunization as compared with that of the control mice The coincidence rate of detection of S japonicum infection using recombinant calpain diagnostic antigen was 100% with that of stool examination It was also noticed that lightly infected sera showed a stronger reaction with the recombinant calpain than those of moderate and heavily infected sera 37% patients with Clonorchis sinensis showed cross-reaction with S japonicum recombinant calpain protein Conclusion S japonicum calpain is an immunogenic protein that is capable of stimulating the production of high level antibody against S japanicum,indicating that it can be used as a candidate vaccine and the antigen for immunodiagnosis of patients with S japanicum