BIOLOGICAL AND BIOCHEMICAL STUDIES OF ANTIGENS ON MALARIA-INFECTED RED CELLS

我们正在研究插入的疟疾蛋白的结构和功能 进入感染成熟无性疟疾的红细胞膜 内皮细胞上的寄生虫和分子参与细胞黏附。 感染恶性疟原虫的超大细胞表面蛋白(Mr 300,000) Aotus猕猴的红细胞现在被证明存在于K+上 感染细胞，而不是K-(即非贴壁)细胞。我们还有 直接从冈比亚疟疾感染的细胞上鉴定出这种分子 病人。目前的实验目的是获得这种蛋白质的序列 以便更准确地研究其在细胞黏附中的作用。 来自冈比亚患者的恶性疟原虫感染红细胞已被显示 通过对同一患者的抗体进行血清学测试来表达 极端程度的抗原性多样性。来自儿童的十个样本表达了 10种不同表型的感染细胞表面抗原(S)。 重要的是，冈比亚成年人的血清中含有识别A细胞的抗体。 疟疾原虫表达的抗原保守性表位 所有患者的感染红细胞。 凝血酶原蛋白，一种通常与凝集有关的蛋白质 活化的血小板，已被确认为一种潜在的 恶性疟原虫感染细胞对内皮细胞的识别作用 细胞黏附现象。这种蛋白质是由内皮细胞合成的。 而且，作为一种涂在塑料或玻璃上的纯蛋白质，会特别结合 K+恶性疟原虫感染细胞，而不是K-细胞。我们正试图 确定受感染红细胞表面成分的性质 与凝血酶原蛋白结合。

We are studying the structure and function of malarial proteins inserted into the membrane of erythrocytes infected with mature asexual malaria parasites and molecules on the endothelial cells involved in cytoadherence. The very large cell surface protein (Mr300,000) on P. falciparum infected erythrocytes from Aotus monkeys has now been shown to be present on K+ infected cells but not K- (i.e. non-cytoadherent) cells. We have also identified this molecule on infected cells directly from Gambian malaria patients. Current experiments aim to obtain the sequence of this protein in order to more precisely study its role in cytoadherence. P. falciparum infected erythrocytes from Gambian patients have been shown by serological tests with antibodies from the same patients to express an extreme degree of antigenic diversity. Ten samples from children expressed ten different phenotypes of the infected cell surface antigen(s). Importantly, sera from Gambian adults contain antibodies which recognize an antigenically conserved epitope expressed by the malaria parasite on infected erythrocytes from all patients. Thrombospondin, a protein generally associated with agglutination of activated platelets, has been identified as a potential lignad for recognition by P. falciparum-infected cells in the endothelial cell cytoadherence phenomenon. This protein is synthesized by endothelial cells and, as a pure protein coated on plastic or glass, will specifically bind K+ P. falciparum-infected cells but not K- cells. We are attempting to identify the nature of the surface component on infected erythrocytes which binds to thrombospondin.