Mechanism for spread of a quasi-enveloped hepatotropic virus

准包膜嗜肝病毒的传播机制

• 批准号: 9788268
• 负责人: Zongdi Feng
• 金额: $ 48.47万
• 依托单位: RESEARCH INST NATIONWIDE CHILDREN'S HOSP
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-19 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9788268
• 关键词: Address; Affect; Antibodies; Antibody Response; Antiviral Therapy; Apical; Bile fluid; Blocking Antibodies; Blood; Blood Circulation; Carrier Proteins; Cell Culture System; Cell Culture Techniques; Cells; Complex; Data; Development; Diagnostic; Ebola virus; Enteral; Enterovirus; Enzymes; FDA approved; Feces; Goals; HIV; Hepatitis A; Hepatitis B; Hepatitis E virus; Hepatocyte; Human; Human poliovirus; Immunity; Immunocompromised Host; Individual; Infection; Knowledge; Lead; Life Cycle Stages; Liver; Liver Fibrosis; MTCH1 gene; Mediating; Membrane; Modeling; Morbidity - disease rate; Multivesicular Body; Mus; Outcome; Palmitic Acylation Site; Pathogenesis; Patients; Play; Process; Proteins; Regulation; Research; Rhinovirus; Role; Serum; Sorting - Cell Movement; Support System; Surface; Testing; Therapeutic Intervention; Vaccines; Viral; Viral Antigens; Viral Envelope Proteins; Viral Pathogenesis; Virion; Virus; Virus Diseases; Work; alanylproline; apical membrane; basolateral membrane; biliary tract; chronic infection; complement system; env Gene Products; improved; in vivo; insight; mortality; neutralizing antibody; new therapeutic target; novel; overexpression; palmitoylation; particle; prolyl-serine; protein transport; seryl-proline; virus envelope

Summary Hepatitis E virus (HEV), an enterically transmitted virus, exists either as naked virions that are shed in the feces or quasi-enveloped virions that circulate in the blood. The quasi-envelopment of HEV facilitates noncytolytic release of virus from infected cells. However, the lack of viral envelope proteins raises question about mechanism for HEV spread and the role of antibodies in natural infection. HEV infects ~20 million people annually and causes significant morbidity and mortality. Persistent HEV infection in immunocompromised individuals can lead to rapid progression of liver fibrosis. Currently there are no FDA-approved diagnostics and HEV-specific therapies. Our long-term goal is to unravel the functional role(s) of this unusual envelopment in the virus life cycle and pathogenesis for the purpose of identifying novel targets for therapeutic intervention. The overall objective of this project is to understand the role of the quasi-envelopment in HEV spread and how it affects antibody-mediated neutralization. The viral ORF3 protein is known to play a key role in HEV envelopment. Our preliminary data suggest that ORF3 is subjected to regulation by palmitoylation to mediate virion release. In addition, we found evidence that neutralizing antibodies block HEV spread in cells that have already established infection. Our central hypothesis is that ORF3-mediated quasi-envelopment is required for HEV release into the bloodstream and into the bile (then shed into feces), and quasi-enveloped HEV particles mediate spread with the liver via a novel entry mechanism that is susceptible to post-entry neutralization by antibodies. We will test this hypothesis in polarized hepatocyte cell culture and in human liver chimeric mice. Aim 1 will define the role of palmitoylation of ORF3 in its cellular localization and function in virus release. Aim 2 will define the cellular requirements and role of ORF3 in HEV spread. Aim 2 will also define the role and mechanism of antibodies in blocking HEV spread. The expected outcomes of the proposed research are novel insights into the spread mechanism for a quasi- enveloped virus, and may have implications for other non-enveloped viruses such as hepatitis A, poliovirus, and enteroviruses that also become quasi-enveloped at certain stages of their life cycle. This work will fill gaps in our understanding of the quasi-envelopment processes and how it influences virus spread, pathogenesis and immunity.

概括 戊型肝炎病毒 (HEV) 是一种肠道传播病毒，以裸露的病毒颗粒形式存在，并随粪便排出 或在血液中循环的准包膜病毒粒子。 HEV 的准包封有利于非溶细胞性 从受感染的细胞中释放病毒。然而，病毒包膜蛋白的缺乏引发了关于机制的疑问 了解 HEV 传播以及抗体在自然感染中的作用。 HEV 每年感染约 2000 万人并导致 显着的发病率和死亡率。免疫功能低下个体持续感染 HEV 可导致快速 肝纤维化的进展。目前尚无 FDA 批准的诊断方法和 HEV 特异性疗法。我们的 长期目标是揭示这种不寻常的包膜在病毒生命周期中的功能作用，以及 发病机制，以确定治疗干预的新靶点。本次活动的总体目标 该项目的目的是了解准包膜在 HEV 传播中的作用以及它如何影响抗体介导的 中和。已知病毒 ORF3 蛋白在 HEV 包膜中发挥关键作用。我们的初步数据 表明 ORF3 受到棕榈酰化的调节以介导病毒颗粒的释放。此外，我们还发现 有证据表明，中和抗体可阻止 HEV 在已感染的细胞中传播。我们的 中心假设是，HEV 释放到血流中需要 ORF3 介导的准包膜 并进入胆汁（然后排入粪便），准包膜的 HEV 颗粒通过肝脏介导传播 新颖的进入机制，容易被抗体进入后中和。我们将检验这个假设 在极化肝细胞培养物和人肝嵌合小鼠中。目标 1 将定义棕榈酰化的作用 ORF3在其细胞定位和病毒释放功能中的作用。目标 2 将定义蜂窝需求和 ORF3 在 HEV 传播中的作用。目标 2 还将定义抗体在阻止 HEV 传播中的作用和机制。 拟议研究的预期结果是对准传播机制的新颖见解 包膜病毒，并可能对其他非包膜病毒有影响，如甲型肝炎、脊髓灰质炎病毒和 肠道病毒在其生命周期的某些阶段也会变得准包膜。这项工作将填补我们的空白 了解准包络过程​​及其如何影响病毒传播、发病机制和 免疫。