Reovirus Modulation of the Cardiac Innate Response: Type I Interferon and HSP25

呼肠孤病毒对心脏先天反应的调节：I 型干扰素和 HSP25

• 批准号: 8389664
• 负责人: BARBARA SHERRY
• 金额: $ 34.39万
• 依托单位: NORTH CAROLINA STATE UNIVERSITY RALEIGH
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-12-01 至 2015-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8389664
• 关键词: Address; Amino Acids; Antiviral Agents; Antiviral Response; Binding; Cardiac; Cardiac Myocytes; Cataloging; Catalogs; Cells; Complex; Disease; Disease Outcome; Evolution; Family; Fibroblasts; Genes; Genetic Transcription; Goals; Heart; Heat shock proteins; In Vitro; Infection; Integration Host Factors; Interferon Type I; Interferons; M2 protein; Mus; Myocarditis; Nuclear; Obstruction; Organ; Participant; Phenotype; Phosphorylation; Play; Protein Binding Domain; Proteins; Proteomics; Reovirus; Reporting; Repression; Role; STAT1 gene; STAT2 gene; Signal Pathway; Signal Repression; Signal Transduction; Stimulus; Stress; Structure; Sudden Death; Sum; Testing; Therapeutic Intervention; Viral; Virus; Virus Diseases; cell injury; cell type; cytokine; human disease; in vivo; insight; member; mouse model; new therapeutic target; novel; novel therapeutics; protective effect; public health relevance; receptor; response; therapeutic target; tool; transcription factor; virus tropism; young adult

DESCRIPTION (provided by applicant): Our overall goal is to identify novel components of the host innate antiviral response and novel mechanisms for viral subversion of this response to impact disease. Cardiac myocytes are essential and non-replenishable, thus the heart is exceptionally dependent on this first-line defense. Indeed, we have shown that the cardiac interferon (IFN) response is unique, and that in reovirus-induced murine myocarditis the IFN response differs between virus strains and is critical for protection. We continue to use this powerful tool-kit of viruses to probe the innate response in a highly vulnerable organ, the heart, and have made two new discoveries. First, we found that reovirus inhibits IFN signaling by an entirely novel mechanism. Specifically, reovirus induces unusual nuclear accumulation of transcription factor IRF9, likely reflecting concomitant interference with IRF9 function in induction of IFN-stimulated genes. This virus strain specific-effect is determined by a single amino acid in reovirus protein ?2. We hypothesize that reovirus protein ?2 modulates IRF9 structure / function to inhibit IFN signaling, and that ?2 repression of IFN signaling in cardiac cells is critical for myocarditis. In Specific Aim 1, we will determine the mechanism for this modulation and its impact on myocarditis and other disease. Results will provide significant new insights into functional domains and protein binding partners of participants in IFN signaling. Second, using a proteomic discovery approach, we identified a new IFN- independent protective response which can be subverted by virus. We found that Heat Shock Protein-25 (Hsp25) is phosphorylated (non-myocarditic reoviruses) or decreased (myocarditic reovirus) in infected cardiac myocytes, and that this is cell type-specific and IFN-independent. Hsp25 is modulated by many viruses and it is protective against stress, particularly in the heart. However, an Hsp25 decrease has never been reported for any stimulus in any cell type. Inhibition of Hsp25 by a highly myocarditic reovirus, but no other stimulus, suggests that Hsp25 is protective and can be subverted by viruses. We hypothesize that phosphorylated Hsp25 plays a cell type-specific protective role during infection, and that viruses can subvert this innate response. In Specific Aim 2, we will determine the protective effects of Hsp25, the mechanisms by which viruses modulate it, and the impact on virus tropism and disease. Results will define a completely new protective response against viral infection. In sum, by studying both a component of the IFN response (IRF9) and an IFN-independent protective factor (Hsp25), we gain a more complete picture of virus modulation of cell factors in disease. By studying cells critically dependent on innate antiviral responses, we uncover effectors that may be present in many cell types but not readily detected. Finally, the remarkably strong correlation between viral effects in cardiac myocyte cultures and murine myocarditis provides an outstanding platform to test hypotheses generated in vitro for their validity in vivo. The broader impact is to increase the catalog of protective host factors that can be sabotaged by viruses and manipulated for therapeutic intervention.

描述（由申请人提供）：我们的总体目标是鉴定宿主先天性抗病毒反应的新组分和病毒颠覆这种反应以影响疾病的新机制。心肌细胞是必不可少的，不可替代的，因此心脏特别依赖于这一第一线防御。事实上，我们已经表明，心脏干扰素（IFN）的反应是独特的，并在呼肠孤病毒诱导的小鼠心肌炎的IFN反应不同的病毒株，是至关重要的保护。我们继续使用这种强大的病毒工具包来探测高度脆弱的器官心脏的先天反应，并取得了两项新发现。首先，我们发现呼肠孤病毒通过一种全新的机制抑制IFN信号传导。具体而言，呼肠孤病毒诱导转录因子IRF 9的异常核积累，可能反映了在IFN刺激基因的诱导中与IRF 9功能的伴随干扰。该病毒株的特异性作用是由呼肠孤病毒蛋白中的一个氨基酸决定的。2.我们假设呼肠孤病毒蛋白？2调节IRF 9的结构/功能，以抑制IFN信号转导，和？2抑制心肌细胞中的IFN信号传导是心肌炎的关键。在具体目标1中，我们将确定这种调节的机制及其对心肌炎和其他疾病的影响。结果将提供重要的新的见解功能域和蛋白质结合伙伴的参与者在IFN信号。第二，使用蛋白质组学发现方法，我们鉴定了一种新的IFN非依赖性保护性应答，其可以被病毒破坏。我们发现，热休克蛋白-25（Hsp 25）在感染的心肌细胞中被磷酸化（非心肌性呼肠孤病毒）或减少（心肌性呼肠孤病毒），并且这是细胞类型特异性的和IFN无关的。热休克蛋白25是由许多病毒调节，它是保护免受压力，特别是在心脏。然而，在任何细胞类型中的任何刺激都从未报道过Hsp 25减少。Hsp 25被高度心肌性呼肠孤病毒抑制，但没有其他刺激，表明Hsp 25是保护性的，可以被病毒破坏。我们假设磷酸化的Hsp 25在感染过程中起着细胞类型特异性的保护作用，而病毒可以破坏这种先天性反应。在具体目标2中，我们将确定热休克蛋白25的保护作用，病毒调节它的机制，以及对病毒嗜性和疾病的影响。结果将定义一种全新的针对病毒感染的保护性反应。总之，通过研究IFN应答（IRF 9）和IFN非依赖性保护因子（Hsp 25）的组成部分，我们获得了疾病中细胞因子的病毒调节的更完整的画面。通过研究严重依赖于先天抗病毒反应的细胞，我们发现了可能存在于许多细胞类型中但不容易检测到的效应子。最后，心肌细胞培养物中的病毒效应与小鼠心肌炎之间的显著强相关性提供了一个出色的平台来测试体外产生的假设在体内的有效性。更广泛的影响是增加了可以被病毒破坏并用于治疗干预的保护性宿主因子的目录。