Bacterially expressed and refolded receptor binding domain of Plasmodium falciparum EBA-175 elicits invasion inhibitory antibodies
Bacterially expressed and refolded receptor binding domain of Plasmodium falciparum EBA-175 elicits invasion inhibitory antibodies
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DOI：
10.1016/s0166-6851(02)00122-6
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发表时间：
2002-08-07
影响因子：
1.5
通讯作者：
Chitnis, CE
中科院分区：
文献类型：
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作者：
Pandey, KC;Singh, S;Chitnis, CE
疟原虫通过特异性受体-配体相互作用侵入红细胞。恶性疟原虫红细胞结合抗原（EBA-175）在侵入人红细胞期间与血型糖蛋白A上的唾液酸残基结合。EBA-175的受体结合结构域位于EBA-175（PtF 2）的保守的氨基末端富含半胱氨酸的区域F2中，其与其它红细胞结合蛋白如间日疟原虫Duffy结合蛋白的结合结构域同源。我们已经开发了以其功能形式生产重组PfF 2的方法。重组PfF 2在大肠杆菌中表达，从包涵体中纯化，氧化重折叠复性，并通过离子交换和凝胶过滤层析纯化至均一。已使用生物化学和生物物理方法表征了重折叠的PfF 2，并显示其是纯的、均质的和功能性的，因为其特异性地结合人红细胞。用重折叠PfF 2免疫产生高滴度抗体，其在体外有效地抑制恶性疟原虫侵入红细胞。重要的是，针对PfF 2产生的抗体阻断恶性疟原虫田间分离株的侵袭，该分离株使用多种途径侵入红细胞。这些观察结果支持开发重组PfF 2作为恶性疟原虫疟疾的候选疫苗。(C)2002 Elsevier Science B. V.保留所有权利。
Malaria parasites make specific receptor-ligand interactions to invade erythrocytes. A 175 kDa Plasmodium falciparum erythrocyte binding antigen (EBA-175) binds sialic acid residues on glycophorin A during invasion of human erythrocytes. The receptor-binding domain of EBA-175 lies in a conserved, amino-terminal, cysteine-rich region, region F2 of EBA-175 (PtF2), that is homologous to the binding domains of other erythrocyte binding proteins such as Plasmodium vivax Duffy binding protein. We have developed methods to produce recombinant PfF2 in its functional form. Recombinant PfF2 was expressed in Escherichia coli, purified from inclusion bodies, renatured by oxidative refolding and purified to homogeneity by ion-exchange and gel filtration chromatography. Refolded PfF2 has been characterized using biochemical and biophysical methods and shown to be pure, homogenous and functional in that it binds human erythrocytes with specificity. Immunization with refolded PfF2 yields high titre antibodies that efficiently inhibit P. falciparum invasion of erythrocytes in vitro. Importantly, antibodies raised against PfF2 block invasion by a P. falciparum field isolate that invades erythrocytes using multiple pathways. These observations support the development of recombinant PfF2 as a vaccine candidate for P. falciparum malaria. (C) 2002 Elsevier Science B.V. All rights reserved.