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弓形虫病的人是一个重大的健康威胁。 这种寄生虫，是威胁生命的感染者， 免疫力低下数百万人面临这一威胁，因为据估计， 人群感染了这种病原体。弓形虫缓殖子的再感染 组织囊肿是弓形虫病再激活的原因，这是无法预防的，因为没有 目前的治疗，消除休眠组织囊肿在慢性感染的个人。 寻找治疗和预防慢性弓形虫病的治疗方案的方法已经 受相关弓形虫阶段的有限可及性和缺乏准确的 体外发育模型。我们提出这项建议的目的就是要打破这些僵局。我们 我们开发了一种新的创新性缓殖子复发的体外模型， 定义宿主细胞特异性（Aim 1a）、全细胞基因表达（Aim 1b）和代谢 当缓殖子转换回速殖子时，以及在 一种新发现的替代途径，其中缓殖子直接复制以改革组织 囊肿这些信息是至关重要的，以了解我们如何可以防止 弓形虫病复活体外发育能力的丧失， 在目前的生产转基因菌株的方案中， 组织囊肿再激活的分子基础。在这个建议中，我们将实施和优化 产生发育能力转基因菌株的创新方法（目标3a），以及 使用这个新的协议来定义细胞周期蛋白和其他蛋白质机制（Aim 3b）， 在调节缓殖子复发和组织囊肿再形成中的作用

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