Molecular Determinants of Sporozoite / Host Cell Interactions

子孢子/宿主细胞相互作用的分子决定因素

• 批准号: 10192640
• 负责人: Stefan HI Kappe
• 金额: $ 47.08万
• 依托单位: SEATTLE CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-09 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10192640
• 关键词: Affinity Chromatography; Architecture; Bacterial Adhesins; Binding; Bite; Blocking Antibodies; Blood; Blood Cells; CD81 gene; Cell Communication; Cell Surface Receptors; Cell membrane; Cells; Cessation of life; Clinical; Complex; Culicidae; Data; Development; Disease; EphA2 Receptor; Epitopes; Erythrocytes; Future; Goals; Hepatocyte; Human; Infection; Intervention; Invaded; Link; Liver; Maintenance; Malaria; Maps; Mediating; Membrane; Membrane Proteins; Methods; Molecular; PDGFRB gene; Parasites; Parasitic infection; Pathway interactions; Plasmodium; Platelet-Derived Growth Factor beta Receptor; Process; Proteins; Publishing; Receptor Cell; Role; Site; Skin; Skin Tissue; Sporozoites; Stream; Surface; Symptoms; TRAP Complex; Travel; Vacuole; Work; base; cell motility; design; disease transmission; effective intervention; global health; in vivo; liver infection; malaria infection; novel; novel strategies; prevent; protein complex; receptor; small molecule inhibitor; spatiotemporal; therapy design; transmission process; vector mosquito

PROJECT SUMMARY/ABSTRACT Malaria, caused by Plasmodium parasites, continues to be a major global health problem, with more than 200 million new infections and nearly 500 thousand deaths annually. Infection initiates when sporozoite stages are inoculated into the skin by the mosquito vector. Sporozoites then move in the skin tissue, enter the blood stream and reach the liver. Sporozoites traverse cells before eventually infecting a hepatocyte within a replication-permissive parasitophorous vacuole (PV). Ensconced in the PV membrane (PVM), a single sporozoite will transmogrify into a liver stage that replicates and then forms tens of thousands of merozoites. These are released from the liver and infect and replicate in blood cells, which causes all clinical symptoms of malaria and enables further parasite transmission. Targeting the pre-erythrocytic sporozoites thus represents an attractive intervention point since they are small in number, and successful disruption of the molecular interactions required for infection would completely prevent disease and transmission. However, little is known about the critical molecular interactions leading to productive sporozoite entry into the host, infection of the liver and invasion of hepatocytes. In this proposal, using novel approaches, we will focus on elucidating the molecular map of infection that involves the sporozoite protein complexes containing P52, P36 and the TRAP complex, and their interactions with the host receptors EphA2, CD81 and PDGFR, respectively. Currently we only know that P36 and P52 are essential for establishing productive hepatocyte infection with a PVM and that the hepatocyte surface receptors EphA2 and CD81 are critical for PVM formation as well. In Aim 1, we will investigate the dynamics and conditions of release of P52 and P36 from sporozoites during interaction with hepatocytes. Following our preliminary isolation of a P52/P36 complex, we will proceed to determine the precise molecular interactions within this complex and its interaction with EphA2, CD81 and any other novel putative receptor(s) identified. In Aim 2, we will focus on the hepatocyte surface to further study the functional significance of EphA2 during hepatocyte invasion and PV formation as well as its relationship to CD81 and novel receptors. In Aim 3, we will investigate a novel parasite-host interaction pair identified by us between host protein PDGFR and the sporozoite adhesin TRAP, and the importance of this interaction for host infection in the context of a large TRAP-containing sporozoite protein complex that we have recently identified. Upon completion of the proposed work we will have a clear molecular map of the interactions of critical sporozoite invasion-related protein complexes and host receptor complexes. This data will be important to design targeted interventions such as infection-blocking antibodies or small molecule inhibitors and as such will contribute to the goal of preventing malaria infection.

项目摘要/摘要 由疟原虫引起的疟疾仍然是一个主要的全球健康问题，有200多个 每年有百万个新感染和近50万死亡。 Sporozoite阶段时感染会引发 通过蚊子接种到皮肤中。然后，孢子虫在皮肤组织中移动，进入血液 流并到达肝脏。在最终感染了一个肝细胞之前 复制 - 验证性寄生液泡（PV）。在PV膜（PVM）中结合，一个 Sporozoite将转变为复制并形成数以万计的Merozoite的肝脏阶段。 这些是从肝脏中释放出来的，并在血细胞中被感染并复制，这会导致所有临床症状 疟疾并实现进一步的寄生虫传播。因此，靶向肉毒前孢子菌素代表 一个有吸引力的干预点，因为它们的数量很小，并且成功破坏了分子 感染所需的相互作用将完全预防疾病和传播。但是，鲜为人知 关于导致产物子孢子进入宿主的临界分子相互作用，肝脏感染 和肝细胞的入侵。在此提案中，使用新颖的方法，我们将重点阐明 涉及含有p52，p36和陷阱的孢子岩蛋白复合物的感染分子图 复杂的及其与宿主接收器EPHA2，CD81和PDGFR的相互作用。目前我们 只知道p36和p52对于用PVM建立生产性肝细胞感染至关重要，并且 肝细胞表面受体EPHA2和CD81对于PVM形成也至关重要。在AIM 1中，我们将 在与孢子源的p52和p36释放的动力和条件 肝细胞。在我们初步隔离p52/p36复合物之后，我们将继续确定 该复合物中的精确分子相互作用及其与Epha2，CD81及其其他任何新颖的相互作用 确定的推定接收器。在AIM 2中，我们将专注于肝细胞表面以进一步研究功能 在肝细胞侵袭和PV形成过程中以Epha2的意义及其与CD81的关系 新颖的接收者。在AIM 3中，我们将调查我们在我们之间确定的一种新颖的寄生虫 - 宿主相互作用对 宿主蛋白PDGFR和Sporozoite粘附蛋白陷阱，这种相互作用对于宿主的重要性 在我们最近发现的大型含诱捕孢子岩蛋白质蛋白复合物的较大含量的孢子岩蛋白质复合物的背景下。 提议的工作完成后，我们将有一个清晰的分子图 Sporozoite侵袭相关的蛋白质复合物和宿主接收器复合物。这些数据对 设计有针对性的干预措施，例如感染阻滞抗体或小分子抑制剂，因此 有助于预防疟疾感染的目标。