CYTOADHERENCE-BLOCKING PEPTIDES AS A THERAPY FOR MALARIA

细胞粘附阻断肽作为疟疾的治疗方法

• 批准号: 2067954
• 负责人: Irwin W Sherman
• 金额: $ 16.38万
• 依托单位: UNIVERSITY OF CALIFORNIA RIVERSIDE
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-12-01 至 1996-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2067954
• 关键词: Aotus; Plasmodium falciparum; Primates; Saimiri; cell adhesion; chemical conjugate; enzyme linked immunosorbent assay; epitope mapping; high performance liquid chromatography; human subject; inhibitor /antagonist; laboratory mouse; malaria; malaria vaccines; monoclonal antibody; nonhuman therapy evaluation; parasitic disease chemotherapy; peptide chemical synthesis; synthetic peptide

Plasmodium falciparum, the most malignant of the four human malarias, contributes to 1-2 million deaths annually. The hallmark of P. falciparum infections is sequestration - the attachment of erythrocytes infected with mature stage parasites (trophozoites/schizonts) to endothelial cells lining the post-capillary venules. Sequestration in the brain microvessels - cerebral malaria--may totally occlude blood flown and result in deep coma and death. Through the use of murine monoclonal antibodies (Mabs) it has been possible to show that parasite-induced modifications in the erythrocyte membrane protein band 3 are directly involved in in vitro adhesion (cytoadherence); it is conceivable these proteins also play a role in vivo (sequestration/cerebral malaria). Based on molecular mapping of the modified forms of band 3 with these anti- adhesion Mabs, peptides were synthesized. Several of these peptides inhibited cytoadherence. To precisely define the sequences critical to adhesion, overlapping peptides corresponding to the amino acids surrounding and included within the binding region of these peptides will be prepared by solid phase synthesis. Peptides will be tested singly and in combination for their capacity to inhibit cytoadherence, and those with the greatest inhibitory activity will be administered to P. falciparum-infected monkeys to determine their capacity for reversal of sequestration. Antisera to the peptides will be prepared in mice, and peptides will be used to vaccinate monkeys. The antisera will be used for epitope mapping and for assessment of strain specificity; anti- sequestering activity of the antisera will be determined, both in vitro and by passive transfer experiments in monkeys. The ligand to which the adhesin binds will be identified using anti-idiotype antibodies and affinity chromatography with immobilized peptide. The administration of adhesion-inhibiting peptides to comatose cerebral malaria patients should unplug microvessels containing packed parasitized red cells and bring the patient out of coma Anti-adhesion therapy and/or vaccination would be ideal in areas where malaria is hyperendemic, since it would reduce both mortality and morbidity in those individuals who were most susceptible-- young children without any natal immunity.

恶性疟原虫是四种人类疟疾中最恶性的一种， 每年造成100-200万人死亡。恶性疟原虫的特征 感染是隔离--被感染的红细胞的附着 成熟期寄生虫(滋养体/裂殖体)感染内皮细胞 毛细血管后小静脉的内层。大脑中的封存 微血管--脑型疟疾--可能会完全阻断血液流动， 会导致深度昏迷和死亡。通过使用小鼠的单抗 抗体(单抗)已经可以证明寄生虫诱导的 红细胞膜蛋白条带3的修饰直接 参与体外黏附(细胞黏附)；可以想象这些 蛋白质也在体内发挥作用(隔离/脑疟疾)。基座 关于带3的修饰形式与这些抗-DNA的分子作图 合成粘附性单抗、多肽。这些多肽中的几个 抑制细胞黏附。为了准确定义关键的序列 粘附性，与氨基酸相对应的重叠多肽 包围和包括在这些多肽的结合区内将 采用固相合成的方法制备。将对多肽进行单独测试和 结合它们抑制细胞黏附的能力，以及那些 抑制活性最强的是P。 感染恶性疟原虫的猴子确定其逆转疟疾的能力 自动减支。这些多肽的抗血清将在小鼠身上制备，并 多肽将被用来为猴子接种疫苗。该抗血清将用于 表位作图和菌株特异性评估；抗- 抗血清的隔离活性将在体外进行测定 并在猴子身上进行被动迁移实验。其配基是 将使用抗独特型抗体和 固定化多肽的亲和层析。管理的管理 黏附抑制肽对昏迷的脑型疟疾患者应 拔掉含有寄生红细胞的微血管，并将 昏迷患者接受抗粘连治疗和/或接种疫苗 在疟疾高度流行的地区非常理想，因为这将减少这两个 最易受感染的人的死亡率和发病率-- 没有任何天生免疫力的年幼儿童。