恶性疟原虫多抗原表位基因的融合与表达

Fusion and Expression of Multiple Epitopes of Malaria P. falciparum

本研究以霍乱毒素B亚基(CT-B)基因为载体,构建了含不同抗原表位的恶性疟原虫的融合基因CTB/ATE和CTB/AWTE。前者除含有恶性疟原虫裂殖子表面主要抗原表位杂合多肽基因SPf66外,还含有很强的T辅助细胞表位CST3和Tc细胞表位;后者在此基础上将我国发现的B细胞表位NKNDD基因经8次串联后融合其中、两种形式的融合基因经测序正确后转入大肠杆菌TK1046中,产量分别为10mg/L及5mg/L。表达产物CTB/AWTE经亲和层析纯化的双抗夹心ELISA测定表明,该融合蛋白在保留了与抗CTB抗体结合的同时,与抗NKNDD单抗的结合效价达1∶8000。

Two fusions CTB/ATE and CTB/AWTE, which contain multiple antigenic epitopcs of Malaria Plasinodium with Cholera toxin B subunit (CT-B) as the carrier were constructed. The former consisis of SFf66. which is the chirm nc epitopes of merozoitic antigens and T cell epitopes CSTE including Th determinant CST3 and Tc determinant CSP (368~390). The later is constructed by inserting a tandem repeat of eight times of a B cell epitope. NKNDD. to the former one. After sequencing, the two plasnnds containing the correct genes under the control of Lac promoter are transferred to bacteria Kscheiiclna coli TK10-16. The expression levels are 10mg/L for CTB/A I'K and 5mg/I, for CTB/AWTE. CTB/AWTE is purified on affinity chromatography column and tested by enzyme linked immune ahsobent assay (El,ISA). It showed that this fusion protein could react not only with monoclonal antibody (McAb) against NKNDD at a high litre of 1 晻 8000 but also with antibody against CTB.