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: 2067953
• 负责人: Irwin W Sherman
• 金额: $ 15.87万
• 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/2067953
• 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.

恶性疟原虫是四个人类疟疾中最恶性的， 每年造成1-200万人死亡。恶性疟原虫的标志 感染是隔离 - 感染红细胞的附着 与内皮细胞成熟的阶段寄生虫（滋养体/精神分子） 衬里毛细血管后静脉。大脑中的隔离 微血管 - 脑疟疾 - 可能完全遮住了流血和 导致昏迷和死亡。通过使用鼠单克隆 抗体（mAb）可以证明寄生虫诱导 红细胞膜蛋白带3中的修饰直接 参与体外粘附（细胞疗法）；可以想象 蛋白质还在体内发挥作用（隔离/脑疟疾）。基于 在带有这些抗 - 粘附mAb，肽合成。这些肽中的几个 抑制细胞疗法。精确地定义至关重要的序列 与氨基酸相对应的粘附，重叠的肽 周围并包括在这些肽的结合区域中 通过固相合成制备。肽将单独测试，并且 结合其抑制细胞疗法的能力，以及 具有最大的抑制活性将用于P。 恶性菌感染的猴子，以确定其逆转能力 隔离。肽的抗血清将在小鼠中制备，并且 肽将用于接种猴子。反塞将用于 表位映射和评估应变特异性；反对- 将在体外确定抗血清的隔离活性 并通过猴子中的被动转移实验。配体 粘附素结合将使用抗IDiotype抗体鉴定 亲和色谱与固定肽。管理 抑制肽对昏迷脑疟疾患者的粘附肽应 拔下含有寄生的红细胞的微血管，并带来 患者不受昏迷的抗粘附疗法和/或疫苗接种 在疟疾高血流行的地区是理想的，因为这将减少两者 那些最容易受到影响的人的死亡率和发病率 - 幼儿没有任何出生的免疫力。