Mechanisms of PSGL-1 restriction of HIV virion infectivity

PSGL-1限制HIV病毒粒子感染性的机制

基本信息

批准号：
9927218
负责人：
YUNTAO WU
金额：
$ 38.68万
依托单位：
GEORGE MASON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/9927218
关键词：
Amino Acids Antiviral Agents Binding Biological Assay CD4 Positive T Lymphocytes Cell membrane Cell surface Cells Clathrin Dimerization Disease remission Down-Regulation E-Selectin Endothelium Exclusion Extracellular Domain Glycoproteins HIV HIV Infections HIV-1 Immune Infection L-Selectin Leukocytes Link Lymphoid Cell Mediating Membrane Mucins Mutagenesis Myeloid Cells N-terminal Natural Immunity P-Selectin P-selectin ligand protein Pathogenesis Pathway interactions Phenotype Process Proteins Receptor Cell Residual state Role Site Structure Structure-Activity Relationship Surface Testing Tissues Ubiquitination Viral Viral Physiology Viral reservoir Virion Virus Assembly base dimer extracellular glycosylation migration novel therapeutic intervention particle receptor trafficking tyrosine O-sulfate ubiquitin-protein ligase virus host interaction

项目摘要

Project Summary/Abstract Mechanisms of PSGL-1 restriction of HIV virion infectivity Restriction factors are an important component of host innate immunity. Studying the anti-HIV mechanisms of restriction factors is central to understanding virus-host interaction. These mechanisms may also offer new therapeutic strategies to inactivate viral reservoirs to achieve lasting HIV remission. Recently, we have identified a new HIV restriction factor, PSGL-1 (P-selectin glycoprotein ligand-1), that can inactivate the infectivity of HIV virions released from HIV producing cells. PSGL-1 is a dimeric mucin-like 120-KD glycoprotein that is primarily expressed on the surface of lymphoid and myeloid cells. PSGL-1 binds to P-, L-, and E-selectin, and mediates leukocyte tethering and rolling on endothelium for leukocyte migration into inflamed tissues. PSGL-1 is also an INF-γ-regulated factor involved in Th1-mediated anti-viral activity. Our preliminary mechanistic studies further revealed that PSGL-1 is incorporated into viral particles, which blocks HIV Env incorporation and disables the ability of virions to attach to target CD4 T cells for infection. In addition, we found that PSGL-1 is antagonized by Vpu and Nef through surface down-regulation. Based on these preliminary studies, we hypothesize that: (1) PSGL-1-mediated restriction of HIV infectivity involves its specific domains; (2) PSGL-1 restricts HIV infectivity likely through competitive exclusion of Env incorporation during viral assembly and steric hindrance of Env binding to cell receptors (3) Nef-mediated PSGL-1 down-regulation is likely achieved through linking PSGL-1 to components of clathrin-dependent trafficking pathways. In this application, we will pursue the following aims: Specific Aim 1 is to characterize PSGL-1 for inactivating HIV infectivity. We propose to identify PSGL-1 domains key to restricting HIV-1. We will determine the structure-function relationship of PSGL-1, defining the roles of PSGL-1 dimerization, N- terminal glycosylation and tyrosine sulfation, N-terminal decameric repeats, and the polybasic region in restricting HIV. Specific Aim 2 is to perform mechanistic studies of PSGL-1 inactivation of HIV viral infectivity. We hypothesized that PSGL-1 restricts HIV infectivity likely through two possible mechanisms: (1) competitive exclusion of Env incorporation during viral assembly; (2) steric hindrance of residual Env binding to cell receptors. We will test these two hypotheses to determine the mechanisms of action. Specific Aim 3 is to study the mechanism of Nef-mediated surface down-regulation of PSGL-1. We will identify functional domains of Nef and PSGL-1 for their involvement in PSGL-1 down-regulation. Nef-mediated PSGL-1 downregulation may facilitate viral spread in immune cells.

项目概要/摘要 PSGL-1限制HIV病毒粒子感染性的机制限制因素是宿主先天免疫研究的重要组成部分。限制因素对于理解病毒与宿主的相互作用至关重要，这些机制也可能提供新的机制。最近，我们制定了灭活病毒治疗库以实现艾滋病毒持久缓解的策略。鉴定出一种新的 HIV 限制因子 PSGL-1（P-选择素糖蛋白配体-1），它可以使 HIV 失活 PSGL-1 是一种二聚体粘蛋白样 120-KD，具有感染性。 PSGL-1 主要表达于淋巴和骨髓细胞表面的糖蛋白，与 P-、L-、和 E-选择素，并介导白细胞在内皮上的束缚和滚动，使白细胞迁移到 PSGL-1 也是一种 INF-γ 调节因子，参与 Th1 介导的抗病毒活性。初步机制研究进一步表明，PSGL-1 被纳入病毒颗粒中，从而阻断 HIV Env 掺入并禁用病毒颗粒附着到目标 CD4 T 细胞进行感染的能力。另外，我们发现PSGL-1通过表面下调而被Vpu和Nef拮抗。在这些初步研究中，我们认为：(1) PSGL-1 介导的 HIV 感染性限制涉及其 (2) PSGL-1 可能通过竞争性排除 Env 来限制 HIV 感染性病毒组装过程中的掺入以及 Env 与细胞受体结合的空间位阻 (3) Nef 介导 PSGL-1 下调可能是通过将 PSGL-1 与网格蛋白依赖性成分连接来实现的在此应用程序中，我们将追求以下目标：具体目标 1 是描述特征。 PSGL-1 用于灭活 HIV 感染性。我们建议确定限制 HIV-1 的关键 PSGL-1 结构域。将确定 PSGL-1 的结构-功能关系，定义 PSGL-1 二聚化的作用，N- 末端糖基化和酪氨酸硫酸化、N 末端十聚重复序列以及多碱基区域具体目标 2 是进行 PSGL-1 灭活 HIV 病毒的机制研究。我们认为 PSGL-1 可能通过两种可能的机制来限制 HIV 的传染性：(1) 病毒组装过程中 Env 掺入的竞争性排除；（2）残留 Env 结合的空间位阻；我们将测试这两个假设以确定作用机制。研究 Nef 介导的 PSGL-1 表面下调机制，我们将确定其功能。 Nef 和 PSGL-1 的结构域参与了 Nef 介导的 PSGL-1 下调。下调可能会促进病毒在免疫细胞中的传播。