REGULATION OF VIRUS-INDUCED PROGRAMMED CELL DEATH

病毒诱导的程序性细胞死亡的调节

• 批准号: 7061620
• 负责人: PAUL D FRIESEN
• 金额: $ 24.6万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7061620
• 关键词: REGULATION; VIRUS; INDUCED; PROGRAMMED; CELL

DESCRIPTION (provided by applicant): Programmed cell death, or apoptosis, is a built-in, signal-induced process by which a cell self-destructs. It is a highly regulated mechanism that is critical for normal development, tissue homeostasis, and the elimination of pathogen-infected cells. In humans, misregulated programmed cell death is associated with tumorigenesis, neurodegenerative diseases, immunodeficiency, and viral pathogenesis. Although many evolutionarily conserved components of the cell death pathway have been identified, the molecular mechanisms involved in cellular regulation of apoptosis are still largely unknown. Since host cell apoptosis can limit virus multiplication, many viruses have evolved diverse strategies to regulate the cell death pathway. The proteins that mediate such viral intervention have provided key insight into the cell death program. The long term objective of this proposal is to define the molecular mechanisms by which apoptosis is regulated through the study of three baculovirus-encoded apoptotic regulators: P35, P49, and IAP. Our approach focuses on the use of baculovirus-infected insect cells as a powerful yet convenient system for molecular analysis of both the induction and suppression of apoptosis. Building on recent advances in the apoptosis field, we use integrated approaches in biochemistry, genetics, and cell biology to determine the molecular mechanism of P49 and IAP anti-apoptotic activity. We focus on P49's novel ability to inhibit an initiator caspase resistant to the pancaspase inhibitor P35 by defining the molecular determinants of caspase selectivity by both irreversible inhibitors. Utilizing the recently discovered capacity of baculoviruses to efficiently deliver apoptotic regulators to cultured Drosophila melanogaster cells, we identify the in vivo targets of P49 and P35 and define the caspase cascade in this model organism. We determine the molecular mechanism of virus IAP anti-apoptotic activity by characterizing the interactions between hybrid IAPs and cellular apoptotic effectors. In concert, we also investigate the functional significance of oligomerization for both viral and cellular IAPs by using novel dominant negative inhibitors. Collectively, these studies are expected to provide new and fundamental information on virus-host interactions and the regulation of programmed cell death in animals. Such knowledge will contribute to the development of therapeutic strategies for apoptosis-associated diseases.

描述（由申请人提供）：程序性细胞死亡或凋亡是一个内置的信号诱导的过程，通过该过程，细胞会自我毁灭。这是一种高度调节的机制，对于正常发育，组织稳态和消除病原体感染的细胞至关重要。在人类中，编程的细胞死亡不正常与肿瘤发生，神经退行性疾病，免疫缺陷和病毒发病机理有关。尽管已经确定了细胞死亡途径的许多进化保守的成分，但涉及细胞凋亡的细胞调节的分子机制仍然在很大程度上尚不清楚。由于宿主细胞凋亡可以限制病毒繁殖，因此许多病毒已经发展出多种策略来调节细胞死亡途径。介导这种病毒干预的蛋白质为细胞死亡程序提供了关键的见解。该建议的长期目标是定义通过研究三个杆状病毒编码的凋亡调节剂的研究来调节细胞凋亡的分子机制：p35，p49和iap。我们的方法侧重于将杆状病毒感染的昆虫细胞用作强大但方便的系统，用于分子分析凋亡的诱导和抑制。在凋亡领域的最新进展的基础上，我们在生物化学，遗传学和细胞生物学中使用综合方法来确定p49和IAP抗凋亡活性的分子机制。我们专注于P49的新型能力，可以通过通过两种不可逆抑制剂来定义caspase选择性的分子决定因素来抑制对Pancaspase抑制剂p35具有抗性的引发剂caspase p35的能力。利用最近发现的杆状病毒能力有效地将凋亡调节剂传递到培养的果蝇杂物细胞中，我们确定了P49和P35的体内靶标，并在此模型有机体中定义了caspase cascade。我们通过表征杂交IAP和细胞凋亡效应子之间的相互作用来确定病毒IAP抗凋亡活性的分子机制。在协同过程中，我们还通过使用新型的显性阴性抑制剂来研究病毒和细胞IAP的寡聚化的功能意义。总的来说，这些研究预计将提供有关病毒宿主相互作用的新的和基本的信息，并调节动物中程序性细胞死亡。这种知识将有助于发展与细胞凋亡相关疾病的治疗策略。