Elucidating the functions of red blood cell factors in malaria parasite invasion

阐明红细胞因子在疟原虫入侵中的功能

• 批准号: 10736484
• 负责人: Elizabeth S. Egan
• 金额: $ 75.9万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10736484
• 关键词: Antibodies; Antimalarials; Avidity; Binding; Biological Assay; CD44 gene; CRISPR/Cas technology; Cell Surface Receptors; Cell surface; Cells; Cellular biology; Cessation of life; Child; Communicable Diseases; Complex; Critical Pathways; Cytoskeleton; DNA; Data; Dependence; Development; Drug resistance; Erythrocytes; Experimental Genetics; Falciparum Malaria; Genetic Engineering; Genetic Screening; Goals; HIV; Hematopoietic stem cells; Human; Individual; Infection; Influenza; Integration Host Factors; Intervention; Invaded; Knowledge; Label; Leishmania; Life Cycle Stages; Ligands; Malaria; Mass Spectrum Analysis; Mediating; Methods; Microscopy; Morbidity - disease rate; Organelles; Paper; Parasites; Plasmodium; Plasmodium falciparum; Play; Post-Translational Protein Processing; Pregnant Women; Prevention; Process; Proteins; Proteomics; Public Health; Publishing; Recombinants; Resistance; Role; Signal Pathway; Signal Transduction; Source; Surface; Testing; Therapeutic; Vaccines; Work; candidate identification; comparative; experimental study; genome editing; human stem cells; imaging platform; insight; live cell imaging; mortality; mutant; new therapeutic target; novel; novel strategies; novel therapeutic intervention; novel therapeutics; novel vaccines; obligate intracellular parasite; parasite invasion; pharmacologic; phosphoproteomics; protein protein interaction; receptor; rhoptry; stem cells; Antibodies; Antimalarials; Avidity; Binding; Biological Assay; CD44 gene; CRISPR/Cas technology; Cell Surface Receptors; Cell surface; Cells; Cellular biology; Cessation of life; Child; Communicable Diseases; Complex; Critical Pathways; Cytoskeleton; DNA; Data; Dependence; Development; Drug resistance; Erythrocytes; Experimental Genetics; Falciparum Malaria; Genetic Engineering; Genetic Screening; Goals; HIV; Hematopoietic stem cells; Human; Individual; Infection; Influenza; Integration Host Factors; Intervention; Invaded; Knowledge; Label; Leishmania; Life Cycle Stages; Ligands; Malaria; Mass Spectrum Analysis; Mediating; Methods; Microscopy; Morbidity - disease rate; Organelles; Paper; Parasites; Plasmodium; Plasmodium falciparum; Play; Post-Translational Protein Processing; Pregnant Women; Prevention; Process; Proteins; Proteomics; Public Health; Publishing; Recombinants; Resistance; Role; Signal Pathway; Signal Transduction; Source; Surface; Testing; Therapeutic; Vaccines; Work; candidate identification; comparative; experimental study; genome editing; human stem cells; imaging platform; insight; live cell imaging; mortality; mutant; new therapeutic target; novel; novel strategies; novel therapeutic intervention; novel therapeutics; novel vaccines; obligate intracellular parasite; parasite invasion; pharmacologic; phosphoproteomics; protein protein interaction; receptor; rhoptry; stem cells

PROJECT SUMMARY/ ABSTRACT Malaria is a leading cause of morbidity and mortality globally, responsible for the deaths of hundreds of thousands of individuals per year, primarily children and pregnant women. Effective control is hampered by the lack of a vaccine and continually emerging drug resistance. Most cases of severe malaria are caused by Plasmodium falciparum, which is an obligate intracellular parasite of human red blood cells (RBCs). Therefore, critical host factors may provide an untapped source of new therapeutic targets. Red blood cell invasion is a complex process that involves interactions between several parasite ligands and host receptors, but there remains a fundamental gap in knowledge regarding the functional role(s) of RBC host factors for P. falciparum. This gap in our knowledge is, in part, due to RBCs being terminally differentiated and lacking DNA, thereby precluding conventional genetic experimentation. To surmount this roadblock, we have recently developed CRISPR-Cas9-based methods to generate null mutants in primary human hematopoietic stem cells and efficiently differentiate them ex-vivo to mature cultured RBCs (cRBCs), opening new opportunities for functional analysis of these important cells. Our objective in this proposal is to comprehensively determine the specific roles and functions of two novel RBC host factors required for P. falciparum invasion, CD44 and CD55, which were recently identified from a forward genetic screen. Our central hypothesis, supported by strong preliminary data, is that these critical surface receptors play distinct yet synergistic roles to facilitate P. falciparum invasion through their interactions with parasite ligands and subsequent signaling to the host cell. In the first aim, we will determine the precise steps involving CD44 and CD55 in P. falciparum invasion of human RBCs using live cell imaging and advanced microscopy. In the second aim, avidity-based and proximity labeling proteomic approaches will be used to identify P. falciparum and RBC binding partners for CD44 and CD55. In the final aim, we will define host RBC signaling pathways activated by P. falciparum invasion, and test their dependence on CD44 and CD55. Together, these studies will generate a comparative understanding of the mechanistic roles of two novel host factors crucial for P. falciparum invasion. In addition to revealing new insights into the fundamental cell biology of Plasmodium invasion and human RBCs, this work will stimulate new therapeutic and vaccine approaches to treat one of the most important infectious diseases of humankind.

项目摘要/摘要 疟疾是全球发病率和死亡率的主要原因，导致数百人死亡 每年成千上万的人，主要是儿童和孕妇。有效控制受到 缺乏疫苗和不断出现的耐药性。大多数严重疟疾病例是由 恶性疟原虫，它是人类红细胞（RBC）的强制性细胞内寄生虫。所以， 关键的宿主因素可能会提供未开发的新治疗靶标的来源。红细胞侵袭是 复杂的过程涉及几种寄生虫配体与宿主受体之间的相互作用，但是 关于恶性疟原虫的RBC宿主因素的功能作用的知识仍然是一个基本差距。 我们所知的差距在某种程度上是由于RBC在最终区分和缺乏DNA上，因此 排除常规遗传实验。为了克服这个障碍，我们最近开发了 基于CRISPR-CAS9的方法在原代人造血干细胞和 有效地将它们离体与成熟培养的RBC（CRBC）区分开 这些重要细胞的分析。我们在此提案中的目标是全面确定特定的 恶性疟原虫入侵CD44和CD55所需的两个新型RBC宿主因子的作用和功能，它们 最近是从正向遗传筛选中鉴定出来的。我们的中心假设，由强大的初步支持 数据是，这些关键的表面受体起着独特但协同的作用，以促进恶性疟原虫的入侵 通过与寄生虫配体的相互作用以及随后向宿主细胞的信号传导。在第一个目标中，我们将 使用活细胞确定涉及CD44和CD55的精确步骤 成像和晚期显微镜。在第二个目标中，基于亲生的和接近标记蛋白质组学 方法将用于确定CD44和CD55的恶性疟原虫和RBC结合伙伴。在最终目标中， 我们将定义由恶性疟原虫入侵激活的宿主RBC信号通路，并测试其对 CD44和CD55。这些研究将共同​​产生对的比较理解 两个新型的宿主因素对于恶性疟原虫入侵至关重要。除了揭示有关基本的新见解 疟原虫入侵和人类RBC的细胞生物学，这项工作将刺激新的治疗和疫苗 治疗人类最重要的传染病之一的方法。