HHV-8 vIRF interactions in the context of infection

HHV-8 vIRF 在感染情况下的相互作用

• 批准号: 8994365
• 负责人: John Nicholas
• 金额: $ 17.62万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8994365
• 关键词: Address; Affinity; Antiviral Agents; Apoptosis; Apoptotic; Ataxia-Telangiectasia-Mutated protein kinase; BCL2 gene; Binding; Biological; Biology; Cell Cycle Arrest; Cell Survival; Cells; Clinical; Cytostatics; Data; Development; EP300 gene; Endothelial Cells; Evaluation; Family; Genes; Genetic Transcription; Goals; Homologous Gene; Human Herpesvirus 8; Immune; Immune response; Individual; Infection; Interferons; Kaposi Sarcoma; Knowledge; Latent Virus; Life Cycle Stages; Lymphoma; Macaca mulatta; Malignant - descriptor; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Multicentric Angiofollicular Lymphoid Hyperplasia; Natural Immunity; Pathogenesis; Pathway interactions; Peptides; Phase; Precipitation; Production; Proteins; Reagent; Reporting; Research; Rhadinovirus; Role; Specific qualifier value; Stress; Surveys; Therapeutic; Therapeutic Effect; Time; Tretinoin; Viral; Viral Proteins; Virus; Virus Diseases; Virus Latency; Work; base; cellular targeting; in vivo; inhibitor/antagonist; lytic replication; member; novel; overexpression; prevent; primary effusion lymphoma; public health relevance; response; viral interferon regulatory factor; viral interferon regulatory factor-1

 DESCRIPTION (provided by applicant): Human herpesvirus 8 (HHV-8) specifies four viral interferon regulatory factor homologues (vIRFs) that represent a novel set of virus-encoded proteins, so-far identified only in HHV-8 and closely related rhesus rhadinovirus. The HHV-8 vIRFs function to inhibit cellular IRF activities and other components of cellular defense pathways that promote cell cycle arrest and apoptosis in response to virus infection. Two of the vIRFs, vIRF-1 and vIRF-3, have been demonstrated to contribute significantly to either virus productive replication (in endothelial cells) or to latently infected cell viability [in primary efusion lymphoma (PEL) cells]; each vIRF is expressed during both latent (PEL) and lytic replication. Both phases of the virus life cycle are important for HHV-8 malignant pathogenesis: Kaposi's sarcoma, PEL, and multicentric Castleman's disease. Known targeted cellular proteins of vIRF-1 include IRFs, p300/CBP transcriptional co-activators required for IRF-mediated responses, IFN/retinoic acid-induced GRIM19, p53, p53-activating ATM kinase, and certain BH3-only (pro-apoptotic) members of the Bcl-2 family; vIRF-3 targets IRFs, p300/CBP, and p53. However, the full repertoire of inhibitory interactions of these pleiotropic proteins is far from clear and the interactions have not been adequately surveyed in the context of latent and lytic replication. Whilst we have determined that vIRF-1 interactions with BH3-only proteins are critical for successful productive replication in endothelial cells, the roles of other vIRF-1 interactions in lytic replication in these and other cells and the contributions of vIRF-1 and its interactions to PEL latency remain unknown. Similarly, the roles of vIRF-3 and its interactions in productive replication and of specific vIRF-3 interactions in latency remain to be determined. To address these issues, we propose to: (1) undertake affinity precipitations of vIRFs 1 and 3 from latently infected PEL and lytically infected PEL and endothelial cells followed by mass spectrometry analysis of co-precipitated cellular proteins; (2) use suppression, overexpression, and binding-competition analyses to identify the contributions of vIRFs 1 and 3, their cellular targets, and particular vIRF-protein interactions to latently infected cell viability and productive replication and to develop inhibitory agents. The project comprises a broadly-visioned but conceptually and experimentally focused analysis of unique viral innate immune evasion proteins whose functional and mechanistic contributions to virus biology are presently unclear. As these proteins are centrally important to both latency and productive replication, information generated from this study could provide the basis for development of novel antiviral and clinical therapies.