间日疟原虫MSP1 C重组蛋白的制备及其在血清学诊断中的应用

目的在大肠埃希菌（E，coli）中表达、纯化间日疟原虫裂殖子表面蛋1C端重组蛋白（rGST—PvMSP1C）作为诊断抗原，评价其在间日疟血清学诊断中的应用价值。方法将含有重组质粒pGEX-4T-2／PvMSP1C的工程菌E．coil BL21（DE3）以IPTG进行诱导表达，表达产物以SDS—PAGE与Western—blot免疫印迹进行鉴定；采用GST融合蛋白层析柱进行分离纯化；以纯化重组蛋白包被酶标板，酶联免疫吸附试验（ELISA）检测间日疟患者血清中的特异性IgG抗体。结果含有重组质粒pGEX-4T-2／PvMSP1C工程菌经IPTG诱导表达的rGST—PvMSP1C重组蛋白大小约63ku，能够被间日疟患者的血清所识别。纯化的重组蛋白SDS—PAGE电泳显示一条预期大小的蛋白条带；以重组蛋白作诊断抗原，67份镜检阳性的间日患者血清标本ELISA均为阳性。55份健康人血清ELISA均为阴性．5份恶性疟患者血清及7份血吸虫患者血清检测结果亦为阴性。结论在大肠埃希菌中表达纯化的间日疟原虫rGST—PvMSP1C蛋白具有免疫反应性，以其作为诊断抗原建立的血清中特异性IgG抗体ELISA检测方法具有良好敏感性和特异性，在间日疟的免疫学诊断中具有一定的推广使用价值。

The preparation of Plasmodium vivax recombinant MSP1C protein and its application in serodiagnosis.

Objective To express and purify the recombinant MSP1 C-terminal fusion protein (rGST-PvMSP1 C) of Plasmodium vivax (P. vivax) in E.coli and use it as diagnostic antigen for serological diagnosis of P. vivax malaria. Methods The E.coli BL21(DE3) containing plasmid pGEX-4T-2/PvMSP1C was cultivated and induced by IPTG. After analyzed by SDS-PAGE and Western-blot assays, the expressed rGST-PvMSP1 C was purified with B-PER GST fusion protein purification kits and used as diagnostic antigen for establishing ELISA method to dectect IgG antibody in serum of P. vivax malaria patients. Results The rGST-PvMSP1C fusion protein was expressed in the E.coli BL21(DE3). The results of SDS-PAGE indicated that the expressed rGST-PvMSP1C was about 63ku,which can be recognized by the serum of Plasmdium vivax infected patients.Using purified rGST-PvMSP1C as diagnostic antigen, 67 P.vivax infected serum samples were all tested positive by ELISA and 55 of healthy individuals negative. No cross reaction was observed using rGST-PvMSP1C to detect the serum of 5 P. falciparum infected patients and 7 samples of schistomomiasis patients. Conclusion The rGST-PvMSP1C protein was expressed and purified from the E.coli BL21(DE3), and estblished ELISA test using it as diagnostic antigen was useful for serological diagnosis of P.vivax malaria patients.