Mechanism of Infectivity Acquisition in African Trypanosomes

项目摘要 解开人类病原体的生物学是理解人类病原体的机制的基础。 致病机理和鉴定宿主生存所必需的基因。本申请集中于 原生动物寄生虫布氏锥虫（Trypanosoma brucei），在人类和动物中引起毁灭性疾病， 撒哈拉以南非洲没有疫苗，治疗药物有严重的副作用， 降低功效。因此，迫切需要进行研究，以更好地了解这些生物学 人类病原体及其在宿主体内生存的机制。T.布鲁塞经历了一个 哺乳动物宿主和吸血采采蝇媒介之间复杂的生命周期， 其他的包括细胞形态、表面被膜成分、代谢、信号通路的变化 和基因表达。因此，这些寄生虫进化出适应性， 在采采蝇的肠道和唾液腺中，以及在哺乳动物的血液中， 主持人通过在非感染性锥虫中过表达单个RNA结合蛋白（RBP 6）， 在体外概括了导致昆虫载体获得感染性的事件，包括 亚环变体表面糖蛋白（mVSG）的表达。拟议工作的总体目标 这是为了确定RBP 6激活发育进程的机制， 代谢环和表征RNA结合蛋白网络，调节发育 程序导致epimastigotes和传染性metacyclics。为了实现这些目标，我们将在 我们在上一个供资期的主要研究结果，即确定了《成果预算制》的初步目标6 功能，描述代谢环的分子特征，以及鉴定一个大的 与导致感染性元周期寄生虫的发育程序有关的分子纲要。 我们将使用创新的方法，包括通过深度突变扫描筛选RBP 6功能 通过结合元环选择和高通量DNA测序， 用RNA-Seq.我们的研究计划提供了独特的机会， 阐明了从非感染性顺循环到感染性后循环的发展程序， T.布鲁氏菌生活史

Project Summary Unraveling the biology of human pathogens is fundamental toward understanding mechanisms of pathogenesis and identifying genes essential for survival in the host. This application focuses on the protozoan parasite Trypanosoma brucei, which causes devastating diseases in humans and animals in sub-Saharan Africa. There are no vaccines, and therapeutic drugs have serious side effects and decreasing efficacy. Thus, there is a pressing need for research to better understand the biology of these human pathogens and the mechanisms they use to survive within their hosts. T. brucei undergoes a complex life cycle between the mammalian host and the blood-feeding tsetse fly vector, which among others involves changes in cell morphology, surface coat composition, metabolism, signaling pathways and gene expression. Consequently, these parasites have evolved adaptations to allow for their survival in both the gut and salivary glands of the tsetse fly, as well as in the bloodstream of their mammalian host. By overexpressing a single RNA-binding protein (RBP6) in non-infectious trypanosomes, we recapitulated in vitro the events leading to acquisition of infectivity in the insect vector, including the expression of metacyclic variant surface glycoproteins (mVSGs). The overall goal of the proposed work here is to identify the mechanism by which RBP6 activates developmental progression to infectious metacyclics and to characterize the RNA binding protein network that regulates the developmental program leading to epimastigotes and infectious metacyclics. To accomplish these goals, we will build on our major findings in the previous funding period, namely the identification of initial targets of RBP6 function, the depiction of the molecular characteristics of metacyclics, and the identification of a large compendium of molecules linked to the developmental program leading to infective metacyclic parasites. We will use innovative approaches involving a screen for RBP6 function with deep mutational scanning by combining metacyclic selection and high-throughput DNA sequencing and analyze gene expression at the single cell level with RNA-Seq. Taken together our research plan provides unique opportunities to illuminate the developmental program leading from non-infective procyclics to infectious metacyclics, a crucial process in the T. brucei life cycle.