Role of band 3 in Malaria Invasion of Red Blood Cells

带 3 在疟疾侵袭红细胞中的作用

• 批准号: 7253918
• 负责人: Athar H. Chishti
• 金额: $ 29.56万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-10 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7253918
• 关键词: Affinity; Amino Acids; Binding; Binding Sites; Biological Assay; Biosensor; Cell membrane; Complex; Data; Development; Erythrocytes; Event; Falciparum Malaria; Glycophorin A; Immune response; In Vitro; Knockout Mice; Life; Ligand Binding; Ligands; Localized; Malaria; Malaria Vaccines; Maps; Merozoite Surface Protein 1; Methods; Neuraminidase; Parasites; Pathway interactions; Peptides; Personal Satisfaction; Play; Proteins; Recombinants; Research Personnel; Role; Sialic Acids; Site-Directed Mutagenesis; Solutions; Specificity; Subunit Vaccines; Surface; Testing; Time; Two-Hybrid System Techniques; Yeasts; antigen binding; base; inhibitor/antagonist; insight; merozoite surface protein; parasite invasion; receptor; receptor function; yeast two hybrid system

DESCRIPTION (provided by applicant): Malaria proteins localized on the surface of the merozoite has been a major target for developing a much needed multi-subunit vaccine for Plasmodium falciparum malaria, which claims over one million lives each year. The immune response to these merozoite proteins is expected to block parasite invasion into host red blood cells (RBCs). A sialic acid-dependent invasion pathway largely influenced by the interaction of parasite EBA-175 (175 kDa erythrocyte-binding antigen) with sialic acid residues of RBC glycophorin A has been well characterized. However, lines of evidence indicate that this invasion pathway is non-essential for parasite survival. Recently, we identified a sialic acid-independent invasion pathway that relies on the binding of P. falciparum merozoite surface protein-1 (MSP1) to RBC band 3. Here, we propose to extend our findings under the following specific aims. (1) Specificity of the MSPl-band 3 interaction. We propose to map the band 3-binding sites within MSP1, determine binding affinity, and examine the effect of MSP1 domains containing the band 3-binding site on P. falciparum invasion into RBCs. (2) Participation of EBA-175 in the sialic acid-independent invasion pathway. Our preliminary evidence indicates that EBA-175 interacts directly with the band 3 receptor and MSP1, presumably by forming a ternary complex, band 3/MSP1/EBA-175. We propose to investigate a potential role of EBA-175 in the band 3-dependent invasion pathway by characterizing the binding interface of the ternary protein complex. Major methods used will include yeast two-hybrid assay, solution-binding assay using BIACORE biosensor, and site-directed mutagenesis. (3) Role of the band 3 receptor in sialic acid-dependent pathway. We propose to examine the invasion inhibition potential of band 3 in the sialic acid-dependent P. falciparum line maintained in vitro. This study will provide the first evidence on whether the band 3 provides a pathway alternative to the sialic acid-dependent pathway or functions as a primary invasion receptor across P. falciparum lines. Together, a clear understanding of the sialic acid-independent invasion mechanism will provide valuable insights into the development of an effective subunit malaria vaccine.

描述（由申请人提供）：植物蛋白质位于Merozoite表面的疟疾蛋白一直是开发用于恶性疟疾疟原虫疟疾的急需的多生产疫苗的主要目标，每年宣称每年超过一百万寿命。对这些蛋白蛋白的免疫反应有望阻止寄生虫入侵宿主红细胞（RBC）。唾液酸依赖性侵袭途径在很大程度上受到寄生虫EBA-175（175 kDa红细胞结合抗原的相互作用）与RBC甘氨酸A的唾液酸残基的相互作用已得到很好的特征。但是，证据表明，这种入侵途径对于寄生虫生存是非必需的。最近，我们确定了一种依赖于唾液酸的侵袭途径，该途径依赖于恶性疟原虫梅罗洛唑岩表面蛋白-1（MSP1）与RBC带3的结合。在这里，我们建议在以下特定目标下扩展我们的发现。 （1）MSPL波段3相互作用的特异性。我们建议绘制MSP1中的频带3结合位点，确定结合亲和力，并检查包含3个结合位点的MSP1结构域对恶性疟原虫入侵RBC的影响。 （2）EBA-175参与唾液酸非依赖性侵袭途径。我们的初步证据表明，EBA-175与Band 3受体和MSP1直接相互作用，大概是通过形成三元复合物，3/MSP1/EBA-175。我们建议通过表征三元蛋白复合物的结合界面来研究EBA-175在3条依赖性侵袭途径中的潜在作用。所使用的主要方法将包括使用Biacore生物传感器的酵母两杂化测定，溶液结合测定和定向诱变。 （3）条带3受体在唾液酸依赖性途径中的作用。我们建议在体外维持的唾液酸依赖性疟原虫线中，检查带3的侵袭抑制潜力。这项研究将提供第一个证据，表明该条带3是否提供了依赖唾液酸依赖性途径的途径，还是在恶性疟原虫线跨性恶性疟原虫线上作为主要入侵受体。总之，对唾液酸独立的侵袭机制的清晰了解将为有效的亚基疟疾疫苗的发展提供宝贵的见解。