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

我们正在研究插入的疟疾蛋白质的结构和功能 进入感染成熟无性疟疾的红细胞膜 寄生虫和参与细胞粘附的内皮细胞上的分子。 恶性疟原虫感染后细胞表面的超大细胞蛋白（Mr 300，000） 来自Aotus猴的红细胞现已显示存在于K+上， 感染的细胞，但不是K-（即非细胞粘附）细胞。 我们还 在冈比亚疟疾的感染细胞上发现了这种分子 患者 目前的实验旨在获得这种蛋白质的序列 以便更精确地研究其在细胞粘附中的作用。 P.冈比亚患者的恶性疟原虫感染的红细胞已经显示， 通过血清学试验，用来自同一患者的抗体表达一种 抗原多样性的极端程度。 10个儿童样本表达了 感染细胞表面抗原的十种不同表型。 重要的是，冈比亚成年人的血清中含有抗体， 疟原虫表达的抗原保守表位 感染的红细胞。 血小板反应蛋白，一种通常与血小板凝集有关的蛋白质， 活化血小板，已被确定为一种潜在的木脂体， 恶性疟原虫感染细胞在内皮细胞中的识别 细胞粘附现象 这种蛋白质由内皮细胞合成 而且，作为一种纯蛋白质，涂在塑料或玻璃上， K+恶性疟原虫感染的细胞，而不是K-细胞。 我们正试图 鉴定受感染红细胞表面成分的性质， 与血小板反应蛋白结合。

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.