Functional assays of Plasmodium vivax DBP, EBP, and RBP2b in erythrocyte invasion in Duffy-Negative Africans

间日疟原虫 DBP、EBP 和 RBP2b 在达菲阴性非洲人红细胞侵袭中的功能测定

• 批准号: 10598381
• 负责人: Eugenia Lo
• 金额: $ 6.09万
• 依托单位: UNIVERSITY OF NORTH CAROLINA CHARLOTTE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-09 至 2023-10-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10598381
• 关键词: Africa; African; African ancestry; Antibodies; Antibody Response; Antigens; Binding; Binding Proteins; Biological Assay; Case Study; Data; Epidemiology; Erythrocytes; Ethiopia; Genes; Genetic; Health; Immune response; In Vitro; Individual; Infection; Invaded; Knowledge; Ligands; Parasites; Patients; Plasmodium vivax; Plasmodium vivax vaccine; Population; Proteins; Reporting; Research; Site; Surface; differential expression; in vivo; molecular marker; screening; transcriptome; transcriptome sequencing; vaccine development

Project Summary Title: Plasmodium vivax Erythrocyte Invasion Mechanisms and Humoral Immune Response in Duffy Negative Africans Individuals of African ancestry are thought to be protected from Plasmodium vivax infection because they lack Duffy antigen expression on the surface of their erythrocytes rendering P. vivax unable to invade their red blood cells. However, an increasing number of P. vivax cases reported across Africa and in Duffy-negative individuals challenges this conventional dogma, raising the possibility that that some lineages of P. vivax may have evolved to use ligands other than Duffy Binding Protein for erythrocyte invasion. The intrinsic invasion mechanism and immune response of Duffy-negative individuals to P. vivax infections are largely unknown. In this application, we will investigate the expression and function of erythrocyte binding genes in Duffy-negative P. vivax and the antibody response of Duffy-negative individuals to P. vivax invasion proteins. There are three specific aims: 1) to identify genes with differential expression between Duffy-positive and Duffy-negative P. vivax by RNA-seq; 2) to determine in vitro binding and invasion activities of P. vivax ligand proteins identified from Aim 1 to Duffy- negative red blood cells; and 3) to examine in vivo antibody levels to targeted P. vivax antigens associated with erythrocyte invasion in Duffy-negative patients. As our study sites in Ethiopia have a large number of P. vivax cases and a significant proportion of Duffy-negative individuals, we have a unique opportunity to study the invasion mechanisms of P. vivax in Africa and fill critical knowledge gaps in how this phenomenon occurs. Our established lab culture facility close to the health centers and successful P. vivax transcriptome data obtained from cultured schizonts have demonstrated the feasibility of the proposed research. Comparison of P. vivax transcriptomes between Duffy-negative and Duffy-positive individuals will provide the first description of the genetic and functional attributes of P. vivax that permit infection of Duffy- negative erythrocytes. These data will be valuable to develop molecular markers that identify P. vivax strains able to infect Duffy-negative individuals. Such markers would enable wide-scale screening and characterization of this phenomenon and could radically change our understanding of P. vivax epidemiology in Africa. Further, the identification of key ligand protein(s) P. vivax uses for Duffy-negative erythrocyte invasion and host immune response will have important implications for P. vivax vaccine development.

项目概要 题目：间日疟原虫红细胞侵袭机制与体液免疫 达菲负面非洲人的反应 人们认为非洲血统的人不会感染间日疟原虫 感染，因为它们的红细胞表面缺乏达菲抗原表达 使间日疟原虫无法侵入其红细胞。然而，越来越多的 非洲各地报告的间日疟原虫病例和达菲阴性个体对此提出了挑战 传统教条，增加了间日疟原虫的某些谱系可能具有的可能性 进化为使用达菲结合蛋白以外的配体进行红细胞侵袭。这 Duffy阴性个体对P.的内在入侵机制和免疫反应 间日感染很大程度上是未知的。在此应用程序中，我们将调查 达菲阴性间日疟原虫红细胞结合基因的表达和功能 以及达菲阴性个体对间日疟原虫入侵的抗体反应 蛋白质。有三个具体目标：1）识别差异表达的基因 通过 RNA-seq 区分 Duffy 阳性和 Duffy 阴性间日疟原虫； 2) 体外测定 从 Aim 1 到 Duffy- 鉴定的间日疟原虫配体蛋白的结合和侵袭活性 红细胞阴性； 3) 检查针对目标间日疟原虫的体内抗体水平 与达菲阴性患者红细胞侵袭相关的抗原。正如我们的研究 埃塞俄比亚的站点存在大量间日疟原虫病例，并且比例很高 对于达菲阴性个体，我们有一个独特的机会来研究入侵 间日疟原虫在非洲的发病机制，并填补这方面的关键知识空白 现象发生。我们在健康中心附近建立了实验室培养设施 从培养的裂殖体中成功获得间日疟原虫转录组数据 证明了所提出的研究的可行性。间日疟原虫的比较 达菲阴性和达菲阳性个体之间的转录组将提供第一个 描述允许 Duffy 感染的间日疟原虫的遗传和功能属性 红细胞阴性。这些数据对于开发分子标记非常有价值 鉴定能够感染达菲阴性个体的间日疟原虫菌株。这样的标记会 能够对这种现象进行大规模筛选和表征，并可以从根本上 改变我们对非洲间日疟原虫流行病学的理解。进一步地，识别 间日疟原虫用于达菲阴性红细胞侵袭和宿主的关键配体蛋白 免疫反应将对间日疟原虫疫苗的开发产生重要影响。