Deciphering apicoplast function during blood stage Plasmodium infection

描述(申请人提供)：由疟原虫寄生虫引起的疟疾是发展中国家的主要传染病杀手。面对对当前最后一线疗法的耐药性，迫切需要新的抗疟疾药物，需要对疟原虫生物学有更深入的了解，以确定可行的治疗靶点。顶体是在疟原虫中发现的一种独特的原核来源的质体细胞器，它对药物和疫苗的开发都有希望，因为它对寄生虫复杂生命周期的每个阶段都是必不可少的。然而，尽管它对寄生虫的生存和细胞器中几种生物合成途径的鉴定很重要，但顶生质体在感染过程中的功能仍然不清楚。我们的长期目标是确定参与质外体功能的特定蛋白质和途径，以用于治疗和疫苗开发。这项建议的目的是破译顶体定位的异戊二烯前体生物合成途径在血液期恶性疟原虫感染中的作用。这一途径特别有意义，因为它1)是原核生物，因此在人类宿主中没有发现，2)可能是血期生长所必需的，3)可能是血期生长过程中来自顶生质体的唯一细胞质代谢物，4)是细胞异戊二烯生物合成所必需的，具有一系列可能是寄生虫独有的潜在下游功能。其具体目的是：1)确定在血期感染过程中类异戊二烯前体生物合成对于实现质外体功能的必要性和充分性；2)鉴定在血期感染过程中由类异戊二烯前体产生的细胞内异戊二烯类化合物。我们提出了创新的化学生物学方法来探索这一途径的功能。这些目标的结果将代表着我们对类异戊二烯前体生物合成在质外体功能和血液阶段恶性疟原虫感染中的理解方面的重大进展。这一知识有可能揭示疟疾发病机制的新方面，并有助于确定抗疟疾药物开发的特定候选药物。这项拟议的研究是微生物病原学和寄生虫学学术生涯指导职业发展计划的一部分。首席调查员是一名受过博士培训的生物化学家/化学生物学家和完成临床病理学驻院培训的传染病病理学家。作为一名独立研究员，我的目标是将化学生物学方法应用于疟疾发病机制的研究。乔·德里西博士一直站在基因组技术应用于疟原虫生物学研究的前沿，他将担任这一项目的导师。职业发展计划还包括任命一个咨询委员会、微生物发病机制方面的课程和研讨会，以及在国际疟疾会议上发表演讲。拟议的研究和职业发展活动将对学术生涯的准备至关重要，并为独立研究的未来提供充足的机会。

DESCRIPTION (provided by applicant): Malaria caused by Plasmodium spp parasites is a leading infectious disease killer in the developing world. In the face of developing resistance against the current last-line therapy, new antimalarials are desperately needed and a greater understanding of Plasmodium biology will be required to identify viable therapeutic targets. The apicoplast, a unique prokaryotically-derived plastid organelle found in Plasmodium, holds promise for both drug and vaccine development as it is essential for every stage in the parasite's complex life cycle. Yet despite its importance to parasite survival and the identification of several biosynthetic pathways in the organelle, the function of the apicoplast during infection remains unclear. Our long-term objective is to identify the specific proteins and pathways involved in apicoplast function for therapeutic and vaccine development. The goal of this proposal is to decipher the role of the apicoplast-located isoprenoid precursor biosynthetic pathway in blood-stage P. falciparum infection. This pathway is of particular interest because it 1) is prokaryotic and therefore not found in the human host, 2) may be essential for blood-stage growth, 3) may be the only cytoplasmic metabolite derived from the apicoplast during blood stage growth, and 4) is required for the biosynthesis of cellular isoprenoids with a host of potential downstream functions that could be unique to the parasite. The specific aims are: 1) to determine the essentiality and sufficiency of isoprenoid precursor biosynthesis for fulfilling apicoplast function during blood-stage infection and 2) to identify the cellular isoprenoids derived from isoprenoid precursors during blood stage infection. We propose innovative chemical biology approaches to probe the function of this pathway. The outcome of these aims will represent a significant advance in our understanding of isoprenoid precursor biosynthesis in apicoplast function and blood-stage P. falciparum infection. This knowledge has the potential to reveal novel aspects of Plasmodium pathogenesis and facilitate identification of specific candidates for antimalarial drug development. The proposed research is part of a mentored career development plan for an academic career in microbial pathogenesis and parasitology. The principal investigator is a PhD-trained biochemist/chemical biologist and infectious disease pathologist completing Clinical Pathology residency training. My goal as an independent researcher is to apply chemical biology approaches to the study of malaria pathogenesis. Dr. Joe DeRisi, who has been at the forefront of the application of genomic technology to the study of Plasmodium biology, will serve as a mentor for this project. The career development plan also includes the appointment of an advisory committee, classes and seminars in microbial pathogenesis, and presentation at international malaria conferences. The proposed research and career development activities will be critical in the preparation for an academic career and provide ample opportunities for a future in independent research.