龚地弓形虫诱发动物和人的生殖障碍的机制尚未阐明，我们推测妊娠期机体雌激素水平的巨大变化是影响弓形虫诱发妊娠动物和人高感染性和致病性的重要原因。本课题组前期研究发现孕酮和雌二醇能够显著影响弓形虫的入侵和增殖，本项目以此为切入点，研究孕酮和雌二醇直接影响弓形虫入侵和增殖的作用机制。通过鉴定两种激素的弓形虫受体，明确激素直接作用于弓形虫的效应方式，阐明两种激素影响弓形虫入侵和增殖的途径、关键因子及信号传导通路等；探查两种激素所诱导的弓形虫靶效应分子，从中筛选出弓形虫调节宿主内环境的调控因子，研究调控因子对虫体繁殖、宿主免疫、宿主细胞代谢的影响以及与胎盘和胚胎损伤之间的关系，阐明调控因子对宿主内环境的调节进而调控弓形虫入侵和增殖的机制。研究结果将揭示两种激素直接影响弓形虫入侵和增殖的作用机制，为深入揭示弓形虫对妊娠宿主的致病机制奠定基础，为防控弓形虫引起妊娠动物和人的生殖障碍提供新思路。

The mechanism of Toxoplasma gondii-induced reproductive disorders of animal and human has not been elucidated. We hypothesized that dramatic changes of estrogen levels during pregnancy may be a primary cause of high infection rate and pathogenicity of T. gondii during pregnancy. Our previous study showed progesterone and estradiol, which significantly rise during pregnancy, could affect the invasion and proliferation of T. gondii dramatically. Taking this as the starting point, we propose to investigate the mechanisms of progesterone and estradiol directly affect the invasion and proliferation of T. gondii. We will identify the receptors in T. gondii to the two hormones, clarity the role of hormones directly on the effect mode of T. gondii and illustrate effects of the hormones on T. gondii invasion and proliferation, key factors and signal transduction pathways. We will also explore the two hormone-induced target effector molecules of T. gondii, screen host environment regulatory factors of T. gondii in the presence of the hormones, and monitor the effects of these factors on T. gondii reproduction, host immunity, host cellular metabolism, placenta and embryos, to clarify the mechanism of regulatory factors on the regulation of the host environment and then regulate the invasion and proliferation of T. gondii. We expect to reveal the mechanisms of hormones on T. gondii invasion and proliferation, and lay a foundation for further studying the pathogenic mechanisms of T. gondii in pregnancy. This research will provide new ideas for preventing and controlling T. gondii from pregnancy and animal reproductive disorders.