Investigation of conserved proteins that regulate transmission of the malaria parasite and Toxoplasma gondii.

疟疾寄生虫、疟原虫和弓形虫是相关的原生动物寄生虫，感染全球人口的1/2，造成巨大的死亡和疾病负担。尽管它们进化出了非常不同的机制来进行宿主之间的传播，但在调控弓形虫包囊发育的分子机制中可能存在保守的特征，这些包囊在摄取和通过胃肠道时存活下来，以及蚊子中肠内疟疾寄生虫卵囊的发育。该项目将研究对这些传播形式的发展至关重要的保守蛋白的作用，目的是确定扰乱寄生虫生命周期的新的治疗靶点。我们以前已经确定了一个大的表面蛋白家族，半胱氨酸重复模块蛋白(CRMPs)，它是疟原虫子孢子发育和从卵囊中排出所必需的。该项目将研究CRMPs在体外包囊发育和体内慢性感染期间在实验可服从弓形虫模型中的作用。同时，将在体外培养的弓形虫包囊中进行高通量CRISPR基因筛选，以确定对包囊发育和寄生虫分化和出口至关重要的新蛋白质。候选基因将在疟原虫和弓形虫中被破坏，并将使用高分辨率显微镜、生化方法和感染分析来评估分化和包囊形成。

The malaria parasite, Plasmodium, and Toxoplasma gondii are related protozoal parasites that infect ~1/2 of the global population and cause a massive burden of death and disease. Although they have evolved very different mechanisms to undergo transmission between their hosts, there may be conserved features in the molecular mechanism that regulate the development of the T. gondii cysts, that survive ingestion and passage through the gastro-intestinal tract, and the development of malaria parasite oocysts in the mosquito midgut. This project will investigate the role of conserved proteins that are essential for the development of these transmission forms, with the aim of identifying new targets of therapeutics that disrupt the parasite lifecycles. We have previously identified a family of large surface proteins, the Cysteine Repeat Modular Proteins (CRMPs), that are essential for Plasmodium sporozoite development and egress from the oocyst. This project will investigate the role of CRMPs in the experimentally-amenable T .gondii model during cyst development in vitro and during chronic infection in vivo. In parallel, high-throughput CRISPR genetic screens will be carried out in T. gondii cysts cultured in vitro to identify novel proteins which are essential for cyst development and parasite differentiation and egress. Candidate genes will be disrupted in Plasmodium and Toxoplasma and differentiation and cyst formation will be assessed using high-resolution microscopy, biochemical approaches and infection assays.