Role of HTLV-1 HBZ in viral infection

HTLV-1 HBZ 在病毒感染中的作用

• 批准号: 10351312
• 负责人: Isabelle Michele Lemasson
• 金额: $ 22.41万
• 依托单位: EAST CAROLINA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-22 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10351312
• 关键词: Address; Affect; Attenuated; Biology; CD4 Positive T Lymphocytes; Cell membrane; Cells; Clinical Treatment; Complex; Coupled; Data; Detection; Development; Disease; E1A-associated p300 protein; EP300 gene; Endocytosis; Endosomes; Event; Foundations; Genes; Genetic Transcription; Giant Cells; Glycoproteins; Human T-lymphotropic virus 1; Immune; Infection; Invaded; Location; Lysosomes; Malignant Neoplasms; Mediating; Membrane; Microtubule-Organizing Center; Modification; Neuraxis; Neurodegenerative Disorders; Pathologic; Pathway interactions; Patients; Pharmaceutical Preparations; Play; Population; Process; Proteins; Recycling; Refractory; Reporting; Retroviridae; Risk; Role; Route; Site; Sorting - Cell Movement; Structure; T-Lymphocyte; Testing; Therapeutic; Translations; Viral; Viral Envelope Proteins; Viral Proteins; Viral Structural Proteins; Virus; Virus Assembly; Virus Diseases; base; disorder risk; improved; in vivo; leukemia; nervous system disorder; novel therapeutics; particle; prevent; receptor; receptor binding; recruit; stem; success; trafficking; transmission process; vaccine development; viral transmission

Human T-cell Leukemia Virus type 1 (HTLV-1) is a complex retrovirus that primarily infects CD4+ T- cells in vivo. HTLV-1 infection is associated with diverse pathological effects, including a fatal form of leukemia and a progressive neurodegenerative disease. As these diseases have proven refractory to numerous therapeutic approaches, current clinical treatments show limited efficacy. Separately, certain aspects of HTLV- 1 biology have hindered the development of a vaccine. One relatively untested approach that may overcome these obstacles is to inhibit the infectious spread of HTLV-1 within the host's T-cell population as a means of reducing the risk of disease development and viral transmission. Central to the development of novel therapies based on this concept is a thorough understanding of the HTLV-1 infection process. HTLV-1 infection between T-cells requires the infected and target cells to come into direct contact. This event triggers polarization of the microtubule organizing center in the infected cell towards the target cell, allowing the HTLV-1 envelope glycoprotein (Env) and other viral structural proteins to translocate to the cell-cell juncture. While Env is central to infection, mechanisms modulating its intracellular trafficking before and during cell-contact-mediated infection are relatively unclear. We recently discovered that the HTLV-1-encoded transcriptional regulator, HBZ, augments infection. We believe this function stems from effects of HBZ on the expression of certain cellular genes that participate in the infection process. Accordingly, we recently found that HBZ activates MYOF transcription. This cellular gene encodes myoferlin, which functions in membrane sorting and plays an important role in endosomal trafficking. Our preliminary data indicate that HBZ activates myoferlin expression by recruiting the cellular coactivator, p300/CBP, to the MYOF gene. Consistent with HBZ-mediated activation, myoferlin is aberrantly expressed in HTLV-1-infected T-cells. Importantly, reduced expression or functional inhibition of myoferlin in these cells inhibits viral infection and diminishes the level of Env. Based on these preliminary data and data from other studies, we hypothesize that myoferlin promotes the trafficking of Env through an endosomal pathway that favors the availability of Env for viral assembly. Without myoferlin, we hypothesize that Env is routed to lysosomes for degradation. We propose to address these hypotheses in Specific Aim 1 in which we will characterize how myoferlin affects Env trafficking in HTLV-1-infected T-cells. Results from this aim will clarify a regulatory mechanism of Env intracellular trafficking that is central to viral infection. Focusing on HBZ- mediated activation of MYOF transcription, we hypothesize that specific compounds that block the interaction between HBZ and p300/CBP will reduce myoferlin expression and, in turn, viral infection. We propose to test this hypothesis in Specific Aim 2 in which we will identify compounds that block the interaction. For HTLV-1 carriers and patients alike, results from this aim will identify compounds with potential therapeutic capabilities.

人类 T 细胞白血病病毒 1 型 (HTLV-1) 是一种复杂的逆转录病毒，主要感染体内 CD4+ T 细胞。 HTLV-1 感染与多种病理效应相关，包括致命的白血病和进行性神经退行性疾病。由于这些疾病已被证明对多种治疗方法均无效，因此目前的临床治疗效果有限。另外，HTLV-1生物学的某些方面阻碍了疫苗的开发。一种相对未经测试的可能克服这些障碍的方法是抑制宿主 T 细胞群中 HTLV-1 的感染性传播，作为降低疾病发展和病毒传播风险的一种手段。基于这一概念的新疗法开发的核心是对 HTLV-1 感染过程的彻底了解。 T细胞之间的HTLV-1感染需要被感染细胞和靶细胞直接接触。该事件触发受感染细胞中的微管组织中心向靶细胞极化，从而使 HTLV-1 包膜糖蛋白 (Env) 和其他病毒结构蛋白易位到细胞-细胞接合处。虽然 Env 是感染的核心，但在细胞接触介导的感染之前和期间调节其细胞内运输的机制相对不清楚。 我们最近发现 HTLV-1 编码的转录调节因子 HBZ 会增强感染。我们相信这种功能源于 HBZ 对参与感染过程的某些细胞基因表达的影响。因此，我们最近发现 HBZ 激活 MYOF 转录。该细胞基因编码肌铁蛋白，其在膜分选中发挥作用，并在内体运输中发挥重要作用。我们的初步数据表明，HBZ 通过将细胞共激活因子 p300/CBP 招募到 MYOF 基因来激活肌成蛋白表达。与 HBZ 介导的激活一致，肌铁蛋白在 HTLV-1 感染的 T 细胞中异常表达。重要的是，这些细胞中肌铁蛋白表达的减少或功能抑制可抑制病毒感染并降低 Env 水平。根据这些初步数据和其他研究的数据，我们假设肌铁蛋白通过有利于 Env 进行病毒组装的内体途径促进 Env 的运输。如果没有肌成蛋白，我们假设 Env 被路由至溶酶体进行降解。我们建议在具体目标 1 中解决这些假设，其中我们将描述肌铁蛋白如何影响 HTLV-1 感染的 T 细胞中的 Env 运输。这一目标的结果将阐明对病毒感染至关重要的 Env 细胞内运输的调节机制。着眼于 HBZ 介导的 MYOF 转录激活，我们假设阻断 HBZ 和 p300/CBP 之间相互作用的特定化合物将减少肌成纤维蛋白表达，进而减少病毒感染。我们建议在具体目标 2 中检验这一假设，其中我们将识别阻断相互作用的化合物。对于 HTLV-1 携带者和患者来说，这一目标的结果将鉴定具有潜在治疗能力的化合物。