VERMONT COBRE: PROJECT 4: SUBVERSION OF HOST CELL SIGNALING BY TOXOPLASMA GONDII

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 *请注意，Mariana Matrajt博士的资助已于09年8月31日终止。* 人类病原体弓形虫是分布最广泛的原生动物寄生虫之一，感染了大约三分之一的世界人口。弓形虫在人类和中间宿主体内的无性复制有两种形式：快速生长的“速殖子”和潜伏的“缓殖子”组织包囊。速殖子是导致急性疾病和先天性神经出生缺陷的罪魁祸首，而分裂较慢的缓殖子形式可能会在组织中潜伏多年，对免疫功能低下的患者构成威胁。速殖子和缓殖子之间的相互转换是寄生虫生存和致病的核心，但在遗传和分子水平上对此知之甚少，这使得理解这一过程成为一个重要的目标。 为了更好地理解速殖子和缓殖子之间转化的生物学过程，我们有兴趣识别参与缓殖子分化过程的基因。为此，我们成功地开发了一种基因筛查，以确定控制寄生虫分化的调控基因，并分离出在分化条件下无法转化为慢性体的突变体。这些突变体中的7个被选择用于进一步的鉴定和微阵列分析。所有这些突变体都表现出显着的复制速度增加和缓体标志物的表达减少，这些特征证实了这些突变体确实存在形成缓体的缺陷。 在前一份报告中，我们描述了对这七个突变体进行的微阵列分析。在过去的一年里，我们完成了对微阵列数据的分析，并于最近提交了这项工作供出版。这项工作的总结如下：

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. ***Please note Dr. Mariana Matrajt's funding was terminated as of 8/31/09.*** The human pathogen Toxoplasma gondii is one of the most widely distributed protozoan parasites, infecting approximately one-third of the world's population. Asexual replication of T. gondii in humans and intermediate hosts is characterized by two forms: rapidly growing 'tachyzoites' and latent 'bradyzoite' tissue cysts. Tachyzoites are responsible for acute illness and congenital neurological birth defects, while the more slowly dividing bradyzoite form can remain latent within the tissues for many years, representing a threat to immunocompromised patients. The interconversion between tachyzoites and bradyzoites, at the heart of parasite survival and pathogenicity, is poorly understood at a genetic and molecular level, which makes understanding this process an important goal. We are interested in identifying genes involved in the bradyzoite differentiation process in order to better understand the biology of the conversion between tachyzoites and bradyzoites. To this end we have successfully developed a genetic screen to identify regulatory genes that control parasite differentiation and have isolated mutants that fail to convert to bradyzoites under differentiation conditions. Seven of these mutants were selected for further characterization and microarray analysis. All these mutants show significantly increased replication rates and reduced expression of bradyzoite markers which are features that confirm that indeed these mutants have defects forming bradyzoites. In the previous report we described the microarray analysis carried out with these seven mutants. In the past year we finished the analysis of the microarray data and recently submitted this work for publication. The summary of this work is as follows: