Cyclophilins and the IFN Response

亲环蛋白和干扰素反应

• 批准号: 8632788
• 负责人: PHILIPPE ANDRE GALLAY
• 金额: $ 39.5万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-05 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8632788
• 关键词: Adverse effects; Affect; Antiviral Agents; Antiviral Response; Binding; Binding Sites; Biological Assay; Cells; Clinical; Complex; Cyclophilins; DNA Binding; Data; Development; Elements; Exhibits; Genetic Transcription; Genotype; Goals; Hepatitis C; Hepatitis C virus; Hepatocyte; IRF3 gene; In Vitro; Individual; Interferons; Isomerase; Kinetics; Link; Lymphocytic choriomeningitis virus; Maps; Mediating; Molecular Conformation; Mus; Mutagenesis; Patients; Phase; Plasma; Play; Population; Prevention; Production; Property; Regimen; Replicon; Resistance; Role; Series; Time; Ubiquitination; Viral; Viral Proteins; Viremia; Virus; Virus Diseases; Work; anti-hepatitis C; hepatoma cell; improved; in vivo; inhibitor/antagonist; innovation; member; mutant; novel; phase 1 study; prevent; public health relevance; research study; response; viral RNA

PROJECT SUMMARY. Cyclophilin (Cyp) inhibitors (CypI) are clinically highly potent in HCV patients in pahse I and II studies. A recent phase I study showed that the daily administration of a CypI reduces viremia and rapidly increases plasma concentrations of IFN¿, ¿1 and ¿3, and 2'5'OAS-1. Changes in plasma concentrations for all markers were coincident with changes in plasma concentration of the CypI. These novel and attractive data revealed the first link between Cyps and the IFN response. We were able to partly reproduce the patient data in vitro. Specifically, CypI enhance secretion of IFN¿, ¿ and 2'5'OAS-1 from replicon cells. These data suggest that activation of the IFN response may represent a mechanism through which CypI exert their clinical antiviral activity. We investigated the possibility that the intracellular target for CypI, CypA, binds to components of the IFN response. Remarkably, we found that CypA binds to the IFN regulatory factor 9 (IRF9) via its isomerase pocket. CypI prevent IRF9-CypA interactions. CypA also binds to IRF3, 5 and 7, suggesting that CypA binds to all IRF members. Our work demonstrates for the first time that CypA binds specifically to a major class of elements of the IFN response - IRFs. It also reveals a novel opportunity to modulate the IFN response. In this application, we propose to extend this work by conducting a series of experiments aimed at dissecting the roles of CypA in the IFN response. This application should elucidate how CypA neutralization triggers IFN production and determine whether the CypI-mediated IFN production represents a new mechanism of antiviral action of CypI. This application should also determine what action or function CypA exerts on IRFs. Interestingly, our most recent work suggests that CypA, by interacting with IRFs, greatly impacts their degree of ubiquitination. We propose a new set of experiments aimed at identifying the link between the CypA-mediated IRF ubiquitination effect and the CypI-mediated activation of the IFN response. Our finding that CypI triggers IFN release from PBMCs isolated from HCV patients opens exciting new lines of enquiries. This ex vivo assay may allow us to determine whether CypI responders produce more IFN than CypI non-responders and whether the CypI response is genotype- or virus titer-specific. If this occurs, we then would use this information to develop an empiric pre-screen for subjects, who are likely to respond to a regimen comprising a CypI. We recently found that CypI administration to mice significantly inhibits the infectivity of a virus, which is unrelated to HCV, but which is also highly sensitive to IFN. Moreover, we found that the IFN plasma levels were superior in infected mice treated with CypI compared to those in untreated infected mice, suggesting that the CypI IFN induction is a more widely used mechanism. These remarkable preliminary finding opened new lines of exciting enquiries. The ultimate goal of this application is to improve our understanding of the role of Cyps in the IFN response to viral infection.

项目摘要。亲环素（Cyp）抑制剂（CypI）在临床上对I期HCV患者具有高度效力 二是研究。最近的一项I期研究表明，每天服用CypI可减少病毒血症， 快速增加IFN <$1和<$3以及2 '5'OAS-1的血浆浓度。血浆变化 所有标记物的浓度与CypI血浆浓度的变化一致。这些新颖 有吸引力的数据揭示了Cyps和IFN应答之间的第一个联系。我们能够部分地 在体外重现患者数据。具体地说，CypI增强IFN-γ和2 '5'OAS-1的分泌， 复制子细胞。这些数据表明，IFN应答的激活可能代表了一种机制， CypI发挥其临床抗病毒活性。我们研究了细胞内靶点的可能性， CypI，CypA，与IFN应答的组分结合。值得注意的是，我们发现CypA与IFN 调节因子9（IRF 9）通过其异构酶口袋。CypI阻止IRF 9-CypA相互作用。CypA还与 IRF 3、5和7，表明CypA与所有IRF成员结合。我们的工作首次证明， CypA特异性结合IFN应答的主要类型的元件- IRFs。它还揭示了一部小说 调节IFN应答的机会。在本申请中，我们建议通过进行 一系列旨在剖析CypA在IFN应答中的作用的实验。该应用程序应 阐明CypA中和如何触发IFN产生，并确定CypI介导的IFN 产生代表CypI抗病毒作用的新机制。该应用程序还应确定 CypA对IRFs的作用或功能。有趣的是，我们最近的工作表明，CypA，通过 与IRF相互作用，极大地影响了它们的泛素化程度。我们提出了一组新的实验 目的是确定CypA介导的IRF泛素化效应和CypI介导的IRF泛素化效应之间的联系。 激活IFN应答。我们发现CypI触发从HCV分离的PBMC释放IFN 病人打开了令人兴奋的新的查询线。这种离体测定可以使我们确定CypI是否 应答者比CypI无应答者产生更多的IFN，并且CypI应答是基因型还是病毒 滴度特异性。如果发生这种情况，我们将使用这些信息为受试者制定经验性预筛选， 可能对含有CypI的治疗方案有反应的患者。我们最近发现给予小鼠CypI 显著抑制病毒的感染性，所述病毒与HCV无关，但也对HCV高度敏感。 的IFN此外，我们发现用CypI处理的感染小鼠的IFN血浆水平比用Cyp I处理的感染小鼠的IFN血浆水平高上级。 在未处理的感染小鼠中，表明CypI IFN诱导是一种更广泛使用的机制。 这些令人瞩目的初步发现开辟了令人兴奋的研究新领域。这个项目的最终目标 应用是为了提高我们对Cyps在IFN应答病毒感染中的作用的理解。