Targeting Apoptosis and Immune Control of Epstein-Barr Virus Infected Tonsillar B Cells

针对 Epstein-Barr 病毒感染的扁桃体 B 细胞的凋亡和免疫控制

• 批准号: 9237256
• 负责人: Micah A. Luftig
• 金额: $ 43.79万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-04 至 2021-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9237256
• 关键词: Accounting; Adult; Antigen-Presenting Cells; Apoptosis; B Cell Proliferation; B-Cell Lymphomas; B-Lymphocytes; Blood Cells; CD8-Positive T-Lymphocytes; Cancer Etiology; Cell Survival; Cells; Complex; Data; Disease; Epithelial Cells; Epstein-Barr Virus Infections; Epstein-Barr Virus Nuclear Antigens; Epstein-Barr Virus latency; GTP-Binding Protein alpha Subunits, Gs; Gene Expression; Genetic Transcription; Goals; HIV; HIV Infections; HIV-1; Hairy Leukoplakia; Haplotypes; Human; Human Herpesvirus 4; Immune; Immune Evasion; Immunosuppression; In Vitro; Individual; Infection; Lead; Life Cycle Stages; Lymphoid Tissue; Lymphoma; Lytic; MHC Class I Genes; Maintenance; Mediating; Membrane Proteins; Messenger RNA; Mitochondria; Modeling; Mouth Diseases; Oral; Oral Ulcer; Oral cavity; Pathogenesis; Periodontitis; Phase; Primary Infection; Process; Proteins; Research; Resistance; Saliva; Signal Pathway; Signal Transduction; T-Lymphocyte; Testing; Tonsil; Transplantation; Up-Regulation; Viral; Viral Genes; Virus; Virus Diseases; Virus Latency; adaptive immune response; base; c-myc Genes; cohort; gammaherpesvirus; immunogenic; in vivo; infected B cell; killings; latent gene expression; lymphoblastoid cell line; pathogen; peripheral blood; prevent; programs; protein expression; public health relevance; therapeutic target; transforming virus

 DESCRIPTION (provided by applicant): Epstein-Barr virus (EBV) is a gamma-herpesvirus that infects nearly 95% of adults worldwide. A potent adaptive immune response against the virus prevents disease in the majority of those infected. However, immune suppression, such as during HIV-1 infection, can promote latent EBV-driven B-cell lymphomas. It is our ultimate goal to define the mechanisms by which EBV establishes latency and how these processes go awry leading to disease. In this proposal, we aim to characterize a newly described early latent phase of EBV infection in primary tonsillar B cells and the mechanisms of EBV-mediated survival and immune evasion important for establishing and maintaining the latency reservoir. It is our central hypothesis that EBV promotes B-cell proliferation and survival through its EBV nuclear antigen (EBNA) proteins during the first two weeks of infection; while later during infection the EBNAs and latent membrane protein 1 (LMP1) are required for survival in the immortalized state. We propose that the importance of this biphasic EBV latent gene expression program is to prevent early recognition of EBV-infected B cells by cytotoxic T cells promoting efficient seeding of the long-term latently infected cell reservoir. We have formulated our central hypothesis based on preliminary data characterizing the temporal viral and host gene expression programs and survival mechanisms following EBV infection of peripheral blood B cells where we found that early after tonsillar B-cell infection, the viral EBNA proteins are expressed at high levels in the absence of appreciable levels of the viral LMPs. Importantly, this latency type (IIb) has been observed in EBV-associated post-transplant and HIV lymphomas. Therefore, the rationale for this proposed research is that understanding the mechanism supporting latency IIb infection by EBV may identify critical therapeutic targets for EBV-associated lymphomas and may inform our understanding of the temporal dynamics of EBV infection and the adaptive immune response to this ubiquitous orally-transmitted pathogen. We plan to test our hypothesis and complete the objectives outlined in this proposal through the following three specific aims: 1) Determine the mechanism regulating the switch in viral gene expression from early, EBNAs only (latency IIb), through late, EBNAs + LMPs (latency III), phases of primary tonsillar B-cell infection, 2) Determine the mechanism of early, NFκB-independent and late, NFκB- dependent EBV-infected tonsillar B-cell survival, and 3) Define the consequences of low LMP1/NFκB activity on EBV-infected B-cell peripheral blood and tonsillar B-cell immune recognition, activation, and killing b T cells.

 描述（由申请人提供）：EB病毒（EBV）是一种γ-疱疹病毒，感染全球近95%的成年人。针对病毒的有效适应性免疫反应可以预防大多数感染者的疾病。然而，免疫抑制，如在HIV-1感染期间，可以促进潜伏的EBV驱动的B细胞淋巴瘤。我们的最终目标是确定EBV建立潜伏期的机制以及这些过程如何出错导致疾病。在这个建议中，我们的目标是表征一个新描述的早期潜伏期的EBV感染的初级扁桃体B细胞和EBV介导的生存和免疫逃避的机制，重要的建立和维持潜伏水库。我们的中心假设是，在感染的前两周，EBV通过其EBV核抗原（EBNA）蛋白促进B细胞增殖和存活;而在感染的后期，EBNA和潜伏膜蛋白1（LMP 1）是永生化状态下存活所必需的。我们认为，这种双相EBV潜伏基因表达程序的重要性在于防止细胞毒性T细胞对EBV感染的B细胞的早期识别，从而促进长期潜伏感染细胞库的有效接种。我们已经基于表征外周血B细胞EBV感染后的时间病毒和宿主基因表达程序和存活机制的初步数据制定了我们的中心假设，其中我们发现在扁桃体B细胞感染后早期，病毒EBNA蛋白在扁桃体B细胞中以高水平表达。 不存在明显水平的病毒LMP。重要的是，这种潜伏期类型（IIb）已在EBV相关的移植后和HIV淋巴瘤中观察到。因此，这项拟议研究的基本原理是，了解支持潜伏期IIb感染的EBV的机制可能会确定关键的治疗靶点EBV相关的淋巴瘤，并可能告知我们的理解的时间动态EBV感染和适应性免疫反应，这种无处不在的口腔传播的病原体。我们计划通过以下三个具体目标来检验我们的假设并完成本提案中概述的目标：1）确定仅从早期EBNA调节病毒基因表达转换的机制（潜伏期IIb），至晚期，EBNA + LMP（潜伏期III），原发性扁桃体B细胞感染的阶段，2）确定早期，NFκ B非依赖性和晚期的机制，NFκB依赖性EBV感染的扁桃体B细胞存活; 3）确定低LMP 1/NFκB活性对EBV感染的外周血B细胞和扁桃体B细胞免疫识别、活化和杀伤B T细胞的影响。