Defining the cell and molecular basis of Toxoplasma recrudescence

项目概要 弓形体病的重新激活对慢性感染者的健康构成重大威胁 这种寄生虫对感染者或成为感染者的人有生命危险 免疫功能低下。数百万人面临这种威胁，因为据估计，三分之一的人类 人群感染了这种病原体。弓形虫缓殖子的复发 组织囊肿是弓形虫病重新激活的原因，由于没有有效的方法，无法预防。 目前的治疗方法可以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治疗方案的方法已经 相关弓形虫阶段的可及性有限，并且缺乏准确的 体外发育模型。我们这项提案的目标是打破这些僵局。我们 开发了一种新的创新的缓殖子复发体外模型，我们将利用它 定义宿主细胞特异性（目标 1a）、全细胞基因表达（目标 1b）和代谢 当缓殖子转变回速殖子时以及在 新发现的替代途径，缓殖子直接复制以改造组织 囊肿。为了了解我们如何预防，我们迫切需要这些信息 弓形体病重新激活。体外发育能力丧失加剧 在目前的方案中，产生转基因菌株也是理解的一个主要障碍 组织囊肿再激活的分子基础。在这个提案中，我们将实施并优化 产生具有发育能力的转基因菌株的创新方法（目标 3a），以及 使用这个新协议来定义具有关键作用的细胞周期蛋白和其他蛋白质机制（目标 3b） 在调节缓殖子复发和组织囊肿重建中的作用

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