弓形虫（Toxoplasma gondii） 是广泛分布的机会性致病原虫，其感染已成为严重的世界性公共卫生问题。作为机体抵抗弓形虫的第一道屏障，巨噬细胞是最容易受到感染的细胞之一。弓形虫可以通过抑制巨噬细胞凋亡的方式，来保证在巨噬细胞内寄生、增殖并有机会传播，是弓形虫免疫逃避的机制之一。我们前期研究发现，棒状体蛋白5（ROP5）是一个在弓形虫感染巨噬细胞中重要的凋亡抑制因子，能够与宿主细胞PKM2相互作用，发挥凋亡抑制的作用。本项目拟利用RT-PCR、Wb、定点突变、CRISPR/Cas9系统敲除基因等技术研究弓形虫ROP5与宿主细胞PKM2蛋白的结合区域、关键氨基酸，以及上、下游通路分子之间的关联，阐明弓形虫ROP5通过宿主PKM2抑制巨噬细胞凋亡及其上、下游信号通路的关系，探讨其凋亡抑制发生的新机制。为寻找新的药物作用靶点和新的疫苗候选分子提供理论基础，对弓形虫防治具有重要的现实意义。

Toxoplasma gondii is the opportunity for broad distribution of pathogenic protozoa, whose infection has become a serious public health problem worldwide. As the first barrier of body resistance to Toxoplasma gondii, macrophages are among the most susceptible-infected cells. Toxoplasma gondii can inhibit apoptosis of macrophages, to guarantee that the parasites within the macrophage, proliferation and had the opportunity to spread, which is one of Toxoplasma gondii immune escape mechanisms. Our previous studies have found, rhoptry protein 5 (ROP5) is an important apoptosis inhibitor in Toxoplasma gondii infection of macrophages, which interacts with host cells M2 isoform of pyruvate kinase (PKM2), play a role of the inhibitor of apoptosis together. This project intends using Real-time PCR, Western-blot, site-specific mutagenesis, Transfection, and CRISPR/Cas9 system gene editing technology to research combined regional or key amino acids of ROP5 and host cell PKM2 protein and the link between the upstream or downstream pathway in order to state ROP5 how to inhibit macrophage apoptosis through host PKM2, discuss new mechanism of apoptosis. It's important practical significance to provide the theoretical basis to find new drug targets, new vaccine candidate and control of Toxoplasma gondii.