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

佛蒙特州 COBRE：项目 4：古氏弓形虫颠覆宿主细胞信号传导

• 批准号: 7610753
• 负责人: MARIANA L MATRAJT
• 金额: $ 19.79万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7610753
• 关键词: Ankyrins; Cell Nucleus; Cells; Computer Retrieval of Information on Scientific Projects Database; Cytoplasm; Failure; Family; Funding; Grant; Human; Immune response; Immune system; In Vitro; Infection; Institution; Invaded; Masks; Molecular; NF-kappa B; NFKB Signaling Pathway; Nuclear Localization Signal; Outcome Study; Parasites; Play; Production; Protein Overexpression; Proteins; Regulation; Research; Research Personnel; Resistance to infection; Resources; Role; Signal Pathway; Signal Transduction; Source; Toxoplasma; Toxoplasma gondii; United States National Institutes of Health; Vermont; Virulent; cellular targeting; cytokine; in vivo; insight; macrophage; mutant; p65; pathogen; prevent; response; transcription factor

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The protozoan parasite Toxoplasma gondii is an important human and veterinary pathogen. The objective of this proposal is to understand how T. gondii interferes with host cell signaling and determine the functional consequences for parasite survival. Invasion of a host by a pathogen usually activates the NF-kB family of transcription factors which play an important role in the regulation of the immune system and are frequently required for resistance to infection. Recent studies have shown that invasion of cells by T. gondii not only fails to activate NF-kB, but this parasite actively inhibits this signaling pathway, enabling the parasite to invade cells without triggering proinflammatory cytokine induction. However, it remains unclear how T. gondii inhibits NF-kB and what is the important cellular target. We propose that when T. gondii infect macrophages the presence of a specific T. gondii factor associates with a p65 NF-kB protein in the cytoplasm masking its nuclear localization signals and preventing its translocation into the nucleus. As a result, expression of NF-kB-dependent cytokines in response to T. gondii in infected macrophages is impaired and, as a consequence, the adaptive immune response is also impaired in vivo. In Specific Aim_ 1 we will identify and characterize parasite factors that are responsible for the inhibition of the NF-kB signaling pathway. We will focus on an ankyrin-containing TgEST 1207539 protein, other parasite proteins that may interact with p65 NF-kB, and on generating parasite mutants that fail to inhibit the activation of NF-kB. In Specific Aim 2 we will examine if failure of T. gondii to inhibit NF-kB restores the ability of macrophages to produce cytokines in vitro. We will study cytokine production of macrophages overexpressing the TgEST 1207539 protein or infected with parasite mutants. In Specific Aim 3 we will evaluate if T. gondii mutants that fail to inhibit NF-kB are less virulent in an in vivo infection. The outcome of these studies will be useful to determine the functional significance of the NF-kB signaling pathway for the immune response to T. gondii. This research will yield new insights into the molecular mechanisms that this parasite uses to manipulate the host cell signaling.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 原生动物寄生虫弓形虫弓形虫是重要的人类和兽医病原体。该提案的目的是了解T. gondii如何干扰宿主细胞信号并确定寄生虫存活的功能后果。病原体对宿主的入侵通常会激活NF-KB家族 在免疫系统调节中起重要作用的转录因子，并且经常需要抵抗感染。最近的研究表明，T。gondii对细胞的侵袭不仅无法激活NF-KB，而且该寄生虫会积极抑制这种信号传导途径，从而使寄生虫能够抑制。 入侵细胞而不会触发促炎细胞因子诱导。然而，尚不清楚T. gondii如何抑制NF-KB以及什么是重要的细胞靶标。我们提出，当T. gondii感染巨噬细胞时，特定的gondii因子与p65 NF-KB蛋白相关 掩盖其核定位信号并防止其易位到核中。结果，在感染的巨噬细胞中对NF-KB依赖性细胞因子的表达受损，因此，体内也会损害自适应免疫反应。在特定的AIM_ 1中，我们将确定 并表征负责抑制NF-KB信号通路的寄生虫因子。我们将专注于含有氨基酸氨基酸氨基蛋白的1207539蛋白，其他可能与p65 NF-KB相互作用的寄生虫蛋白，以及产生未能抑制NF-KB激活的寄生虫突变体。在特定目标2中 我们将检查T. gondii抑制NF-KB是否恢复巨噬细胞在体外产生细胞因子的能力。我们将研究过表达巨噬细胞的细胞因子产生，过表达tgest 1207539蛋白或被寄生虫突变体感染。在特定目标3中，我们将评估是否无法 抑制NF-KB在体内感染中的毒性较小。这些研究的结果将有助于确定NF-KB信号传导途径的功能意义。 这项研究将产生有关该寄生虫操纵宿主细胞信号传导的分子机制的新见解。