重组Calpain蛋白的免疫原性及其诊断上的应用研究

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周后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特异性抗体也有显著性的上升; Calpain重组抗原血清诊断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, 说明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.

A Study on Immunogenicity of Recombinant Calpain and It's Application in Diagnosis

Objective The recombinant calpain was used to immunize BALB/C mouse,and the dynamic changes of IgG and it's subtype (such as IgG1,IgG2a,IgG2b and IgG3) were detected by ELISA method. The calpain was used as antigen,serum of patients,whose dejecta had schistosome,was used as primary antibody,the serum of patient who had Clonorchis sinensis was used as control for cross-react. Results The results showed that the recombinant calpain could stimulate mouse to produce a very high anti-calpain antibody titer after immunizing react,and the IgG reached the peak after four weeks,its subtype (including IgG1,IgG2a and IgG2b) also had a significant increasing. The detected results by using calpain and patient's serum to diagnose schistosomiasis were in accord with the results by measuring dejecta. The individuals of low EPG,who was positive of schistosomiasis by measuring dejecta,had higher anti-calpain antibody titer,meanwhile,the individuals of high EPG had higher anti-calpain antibody titer. The ratio of cross-react with Clonorchis sinensis were 37% in ELISA dignosis of schistosomiasis. Condusion Calpain can be developed as a diagnostic antigen for Schistosoma japonicum and is a good candidate of vaccine.