Identification of essential host cell factors for the survival of the obligate intracellular apicomplexan parasite Toxoplasma gondii

Apicomplexa门由5000多种寄生物种组成，这些寄生物种会引起人和动物的多种疾病。这些寄生虫是专性胞内寄生虫，高度依赖宿主细胞因子。虽然宿主细胞的入侵发生在一个独立于宿主细胞吞噬作用的活跃过程中，其中包括寄生虫的滑动能力，但寄生虫的细胞内生存高度依赖于宿主细胞的新陈代谢和寄生虫干扰、调节和利用宿主细胞的信号级联以达到其自身目的的能力。虽然对参与这些机制的基本寄生虫蛋白的了解正在增加，但目前对参与发病的特定相互作用伙伴和宿主细胞因子的了解仍处于初级阶段。该方案的目的是对将作为弓形虫宿主细胞的HeLa细胞进行全基因组RNAi筛选，以确定来自宿主细胞的必要因子，这些因子是入侵、细胞内复制和出口所必需的。因此，经RNAi处理的HeLa细胞将感染弓形虫，并将随着时间的推移跟踪寄生虫的繁殖。我们的目标是确定对寄生虫的成功繁殖至关重要的因素，而宿主细胞本身的生存能力不受影响。这不仅将拓宽我们对宿主-寄生虫相互作用的了解，还可能导致识别针对顶复合体寄生虫的新候选药物。

The phylum Apicomplexa is composed of over five thousand parasitic species, which cause several diseases in humans and animals. These parasites are obligate intracellular and highly dependent on host cell factors. Whereas invasion of the host cell occurs in an active process independently of host cell phagozytosis that involves the parasites ability to glide, the intracellular survival of the parasite highly depends on host cell metabolism and the ability of the parasite to interfere, modulate and use signaling cascades of the host cells for its own purpose. While knowledge of essential parasite proteins involved in these mechanisms is increasing current understanding of the specific interaction partners and host cell factors contributing to pathogenesis is still in its infancy. The purpose of this proposal is to perform a genome wide RNAi screen on HeLa cells that will serve as host cells for Toxoplasma gondii in order to identify essential factors derived from the host cell, needed for invasion, intracellular replication and egress. Therefore RNAi-treated HeLa cells will be infected with T.gondii and propagation of the parasite will be followed over time. We aim to identify factors that are essential for successful propagation of the parasite whereas host cell viability itself is not affected. This will not only broaden our knowledge on host-parasite interactions but might also lead to the identification of new drug candidates against apicomplexan parasites.