Role of host cell metabolism in supporting intracellular Trypanosma cruzi growth

描述（由申请方提供）：克氏锥虫是引起人类恰加斯病的原生动物寄生虫，是一种专性细胞内病原体，在哺乳动物宿主细胞的细胞质中生存和分裂。尽管其在组织感染，持久性和疾病的重要性，目前知之甚少的细胞内无鞭毛体阶段的克氏锥虫的生物学。特别是，宿主细胞对支持T.克鲁奇仍然基本上不为人所知。为了确定细胞内T细胞的关键热细胞调节因子。cruzi感染，我的实验室已经建立并进行了高通量全基因组功能筛选，以鉴定作为细胞内寄生虫生长调节剂的宿主细胞途径/过程。宿主细胞脂肪酸代谢出现在 该筛选作为调节细胞内T细胞生长的主要途径。克氏无鞭毛体。我们还观察到细胞内T. Cruzi无鞭毛体隔离宿主细胞糖原，其中糖原颗粒在胞质无鞭毛体附近高度富集。这些新的发现强烈暗示了T。cruzi来调节感染的宿主细胞中的宿主代谢功能。为了支持这一假设，PDK 4，细胞中葡萄糖和脂肪酸利用之间的转变的主要调节剂（有利于脂肪酸利用）被证明对于支持细胞内T细胞是重要的。克鲁奇生长这是一个有趣的问题，因为T。Cruzi在体内表现出对偏向脂肪酸利用的肌肉细胞的嗜性。虽然存在许多研究哺乳动物细胞代谢的工具，但这些工具尚未应用于T.克氏感染因此，这个探索性的R21建议的目的是建立一个实验框架，主要是为代谢疾病（糖尿病，癌症等）的研究开发的方法和工具，这将使我们能够确定在T. cruzi感染的宿主细胞以及这如何影响细胞内寄生虫的生长。了解宿主代谢与T. cruzi无鞭毛体的生长将提供一个关键的生物学片段，这是目前我们对T. cruzi宿主相互作用，并将有助于阐明新的目标，为控制T。克氏生长 公共卫生相关性： 我们的研究重点是克氏锥虫，这是一种引起人类恰加斯病的原生动物寄生虫，恰加斯病是全球慢性感染性心肌炎的主要原因。鉴于哺乳动物宿主细胞在支持细胞内T细胞生长和存活中的重要作用，cruzi，据预测，宿主和寄生虫的代谢过程密切相关。我们最近的数据为宿主脂肪酸代谢在支持T细胞内生长中的作用提供了功能证据。克鲁兹本研究的目的是建立一个实验框架，在此框架内，我们可以检验宿主细胞代谢在支持T。克鲁奇生长

DESCRIPTION (provided by applicant): Trypanosoma cruzi, the protozoan parasite that causes human Chagas' disease, is an obligate intracellular pathogen that lives and divides in the cytoplasm of its mammalian host cell. Despite its importance in tissue infection, persistence and disease, little is currently known about the biology of the intracellular amastigote stage of T cruzi. In particular, the essential contributions of the host cell toward the support of intracelluar replication and survival of T. cruzi remain largely unknown. With a view to identifying critical hot cell regulators of intracellular T. cruzi infection, my laboratory has established and conducted a high-throughput genome-wide functional screen to identify host cell pathways/processes that function as regulators of intracellular parasite growth. Host cell fatty acid metabolism emerged in this screen as a major pathway regulating growth of intracellular T. cruzi amastigotes in HeLa cells. We also made the observation that intracellular T. cruzi amastigotes sequester host cell glycogen, where glycogen particles are highly enriched in the vicinity of the cytosolic amastigotes. These novel findings are strongly suggestive of the ability of T. cruzi to modulate host metabolic functions in infected host cells. In support of this hypothesis, PDK4, the main regulator of the shift between glucose and fatty acid utilization in cells (favoring fatty acid utilization) was shown to be important for supporting intracellular T. cruzi growth. This is intriguing given that T. cruzi exhibit tropism in vivo for muscle cells that are biased toward fatt acid utilization. While many of the tools exist to study metabolism in mammalian cells, these tools have yet to be applied to the study of host cell metabolism in the context of T. cruzi infection. Thus, the aim of this exploratory R21 proposal is to establish an experimental framework with methodologies and tools developed primarily for studies of metabolic disease (diabetes, cancer etc) that will allow us to determine the extent to which host cell metabolism is altered in T. cruzi-infected host cells and how this impacts intracellular parasite growth. Understanding the intimate relationship between host metabolism and T. cruzi amastigote growth will provide a critical piece of biology that is currently lacking in our knowledge of T. cruzi-host interactions and will help to elucidate novel targets for the control of T. cruzi growth PUBLIC HEALTH RELEVANCE: Our studies focus on Trypanosoma cruzi, the protozoan parasite that causes human Chagas' disease, the leading cause of chronic infectious myocarditis worldwide. Given the essential role of the mammalian host cell in supporting growth and survival of intracellular T. cruzi, it is predicted that the host and parasite metabolic processes are intimately linked. Our recent data provide functional evidence for the role of host fatty acid metabolism in supporting intracellular growth of T. cruzi. The aim of the proposed study is to establish the experimental framework within which we can test specific hypotheses regarding the role of host cellular metabolism in supporting T. cruzi growth.