Defining the cell and molecular basis of Toxoplasma recrudescence

项目摘要 弓形虫病的重新激活对慢性感染者的健康构成重大威胁 这是一种寄生虫，对正在或成为 免疫功能受损。数以百万计的人面临着这种威胁，因为据估计，三分之一的人类 人群感染了这种病原体。弓形虫缓殖子的复燃 组织囊肿是弓形虫病重新激活的原因，这是无法预防的，因为没有 目前的治疗方法是消除慢性感染者的休眠组织囊肿。 寻找治疗和预防慢性弓形虫病的解决方案的方法有 由于获得相关弓形虫阶段的机会有限，以及缺乏准确的 体外发育模型。我们在这项提案中的目标是打破这些僵局。我们 已经开发出一种新的缓殖子复发体外创新模型，我们将利用 确定宿主细胞特异性(目标1a)、全细胞基因表达(目标1b)和代谢 改变(目标2)当缓殖子转换回速殖子时展开，也在 新发现的另一种途径，即缓殖子直接复制以改造组织 囊肿症。这一信息对于理解我们如何防止 弓形虫病重新激活。体外发育能力的丧失加剧了 在目前的方案中，产生转基因菌株也是理解 组织囊肿复活的分子基础。在这份提案中，我们将实施和优化 产生具有发育能力的转基因菌株的创新方法(目标3a)，以及 使用这个新的方案来定义周期蛋白和其他蛋白质机制(目标3b)，这些机制具有关键的 对缓殖子复发和组织囊变的调控作用

Project Summary Reactivation of toxoplasmosis is a significant health threat to people chronically infected with this parasite and is life-threatening to infected individuals that are or become immunocompromised. Millions of people face this threat as it is estimated one third of human populations are infected with this pathogen. Recrudescence of the Toxoplasma bradyzoite tissue cyst is the cause of toxoplasmosis reactivation, which can not be prevented as there is no current treatment that eliminates the dormant tissue cyst in chronically infected individuals. Approaches to find therapeutic solutions to treat and prevent chronic toxoplasmosis have suffered from limited accessibility to the relevant Toxoplasma stages and a lack of accurate in vitro developmental models. Our goal in this proposal is to breakthrough these impasses. We have developed a new innovative ex vivo model of bradyzoite recrudescence that we will utilize to define the host cell specificity (Aim 1a), whole-cell gene expression (Aim 1b) and metabolic changes (Aim 2) that unfold when a bradyzoite converts back to the tachyzoite and also in a newly discovered alternate pathway where bradyzoites directly replicate to reform the tissue cyst. This information is critically needed in order to understand how we might prevent toxoplasmosis reactivation. The loss of developmental competency in vitro that is exacerbated in current protocols producing transgenic strains is also a major impediment to understanding the molecular basis of tissue cyst reactivation. In this proposal, we will implement and optimize an innovative approach to generate developmentally competent transgenic strains (Aim 3a), and use this new protocol to define cyclin and other protein mechanisms (Aim 3b) that have critical roles in regulating bradyzoite recrudescence and tissue cyst re-formation