Uncovering the parasite and host determinants of Plasmodium vivax hypnozoite formation and development using single cell sequencing and human liver-chimeric mice

引起人类疟疾的寄生虫间日疟原虫在地理上分布最广 疟原虫的种类间日疟原虫是亚洲，大洋洲， 中美洲和南美洲，以及非洲之角。在这些地区，妊娠妇女中的间日疟原虫感染 妇女在很大程度上造成早孕流产、出生体重下降和婴儿死亡。值得注意的是，P。 间日疟原虫由于其独特的生物学特性而成为疟疾根除竞技场中的主要关注点。间日疟原虫P. vivax 肝细胞的子孢子感染性并不总是导致胚胎生殖的开始和向血液的转化 阶段疾病，如恶性疟原虫的情况。相反，子孢子可以进入宿主肝细胞， 去分化，然后在宿主肝细胞内休眠数周、数月甚至数年， 重新激活这种休眠或潜伏的肝脏阶段形式被称为催眠子， 在消灭疟疾方面，催眠虫是一个可怕的敌人。事实上，P. 热带和温带气候区的间日疟原虫是由于寄生虫的能力， 催眠虫，其在重新激活后，引起血液期感染复发和伴随传播。 抗疟药物几乎只针对生命周期的症状性血液阶段，而不针对 催眠子以及因此用标准药物方案治疗间日疟原虫血液期感染允许 进一步复发，并且将无助于根除疾病。 从历史上看，唯一批准的抗间日疟原虫催眠虫的药物是伯氨喹， 一种改进的8-氨基喹啉药物，他非诺喹，最近已被批准用于治疗复发性 疟疾不幸的是，伯氨喹的半衰期短，剂量方案长，与葡萄糖-6- 磷酸脱氢酶缺乏症，防止其用于大规模消除运动。因此，有一个 需要新的干预措施，将产生负面影响催眠虫的形成，生存和复发。因此 这项建议的研究目的是揭示催眠虫的生物学见解。本申请旨在解决 关于间日疟原虫催眠子生物学的三个关键生物学问题，并回答这些问题 应该有助于发现新的干预措施，以防止催眠虫复发和持续传播， p.间日疟原虫病 具体来说，间日疟原虫子孢子中是否存在预先编程的内在因子， 决定它到达肝脏后的命运，成为一个复制体或休眠的催眠体？ 休眠的催眠子如何操纵宿主细胞以维持其长期居住？可以 我们开发了一个催眠子复发的模型，以便深入了解促进催眠子复发的触发因素。 重新激活？使用人肝嵌合小鼠模型以及单细胞移植的创新方法 分离和转录谱分析，我们希望能够应对这些挑战。

The human malaria-causing parasite Plasmodium vivax is geographically the most widespread of all the Plasmodium species. P. vivax is a major cause of morbidity in endemic regions of Asia, Oceania, Central and South America, as well as the horn of Africa. In these regions, P. vivax infections in pregnant women significantly contribute to early pregnancy loss, reduced birth weight and infant mortality. Notably, P. vivax is a major concern in an arena of malaria eradication due to its unique biology. Specifically, P. vivax sporozoite infectivity of hepatocytes does not always lead to the onset of schizogony and transition to blood stage disease, as is the case for P. falciparum. Rather, a sporozoite can enter a host hepatocyte, dedifferentiate and then lie dormant within the host hepatocyte for weeks, months or even years, before reactivating. This dormant or latent liver stage form is known as the hypnozoite and in continued efforts towards malaria elimination and eradication, the hypnozoite is a formidable foe. Indeed, the endemicity of P. vivax throughout tropical as well as temperate climate zones is attributed to the parasite’s ability to form hypnozoites, which after reactivating, case relapses of blood stage infection and concomitant transmission. Antimalarial drugs almost exclusively target the symptomatic blood stage of the life cycle and do not target the hypnozoite and thus treatment of P. vivax blood stage infections with standard drug regimens allows for further relapses and will not aid in disease eradication. Historically, the only approved drug active against P. vivax hypnozoites was primaquine although an improved 8-aminoquinoline drug, tafenoquine, has recently received approval for the treatment of relapsing malaria. Unfortunately, primaquine’s short half-life, long dosage regimen and incompatibility with glucose-6- phosphate dehydrogenase deficiency, prevent its use for mass elimination campaigns. Thus, there is a need for novel interventions that will negatively affect hypnozoite formation, survival and relapse. Thus, the research in this proposal aims to shed biological insight on the hypnozoite. This application aims to address three critical biological questions pertaining to P. vivax hypnozoite biology and answering these questions should aid in the discovery of novel interventions to prevent hypnozoite relapse and the continued spread of P. vivax disease. Specifically, are there intrinsic factors that are pre-programmed in the P. vivax sporozoite that determine its fate once it reaches the liver to become either a replicating schizont or a dormant hypnozoite? How does the dormant hypnozoite manipulate its host cell in order to maintain its long-term residency? Can we develop a model of hypnozoite relapse in order to gain insight into the triggers that promote hypnozoite reactivation? Using a human-liver chimeric mouse model alongside innovative methods of single cell isolation and transcriptional profiling, we hope to being to address these challenges.