Restriction of HIV infection by SAMHD1 protein

SAMHD1蛋白限制HIV感染

• 批准号: 8409956
• 负责人: Jacek Skowronski
• 金额: $ 51.32万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8409956
• 关键词: Acquired Immunodeficiency Syndrome; Address; Amino Acid Sequence; Antiviral Therapy; Autoimmune Diseases; Binding; Biochemical; Biological Assay; Blood Cells; CD34 gene; Cell physiology; Cells; Complementary DNA; Conceptions; Data; Dendritic Cells; Development; Diffusion; Elements; Enzymes; Goals; HIV; HIV Infections; HIV-1; HIV-2; Immune response; In Vitro; Infection; Knowledge; Lead; Lentivirus Infections; Leukocytes; Life; Link; Mediating; Metabolism; Modeling; Molecular; Mutation; Myelogenous; Myeloid Cells; Nuclear; Nuclear Protein; Nucleic Acids; Outcome; Pathogenesis; Pathway interactions; Play; Population; Post-Translational Protein Processing; Primate Lentiviruses; Proteins; Proteomics; Regulation; Relative (related person); Reporting; Research; Role; SAM Domain; SIV; Site; Stem cells; Syndrome; Tertiary Protein Structure; Testing; Therapeutic Intervention; Tissues; Viral; Virion; Virus; Virus Diseases; base; cell type; improved; macrophage; multicatalytic endopeptidase complex; pathogen; positional cloning; prevent; progenitor; protein degradation; research study; tripolyphosphate; ubiquitin-protein ligase; viral detection

DESCRIPTION (provided by applicant): Macrophages and dendritic cells have key roles in viral infections, providing virus reservoirs that frequently resist anti-viral therapies and linkin innate virus detection to anti-viral adaptive immune responses. Human immunodeficiency virus 1 (HIV-1) fails to transduce dendritic cells and has a reduced ability to transduce macrophages, due to a potent early post-entry restriction preventing accumulation of viral cDNA. The restriction is to a large extent mediated by cellular SAMHD1 protein, mutations in which lead to Aicardi Goutieres Syndrome (AGS), an autoimmune disease associated with activation of the innate immune response thought to be provoked by endogenous nucleic acids. Importantly, SAMHD1 is targeted for degradation by the Vpx protein of HIV-2/SIVsm viruses, consistent with its key role in inhibiting primate lentivirus infection. These findings indicate that SAMHD1 mediates potent and relevant restriction in key cell types that orchestrate the immune response to HIV infection, and hence could determine long-term outcomes of antiviral therapies. We propose to elucidate the cellular and molecular mechanisms that control and mediate the restriction of HIV infection by SAMHD1. Experiments in aim 1 will define the functional organization of the SAMHD1 protein in the context of viral and cell-based assays, and assess the relationship between virologic and cellular functions of SAMHD1. Experiments in aim 2 will assess how SAMHD1 interferes with HIV-1 cDNA synthesis. Our data suggest that SAMHD1 deoxynucleoside triphosphate triphosphohydrolase (dNTPase) catalytic activity is regulated in cels, as is the case with other cellular enzymes, and per se is not sufficient to restrict HIV infection. Hence, SAMHD1 catalytic activity under restrictive vs non-restrictive conditions will be characterized and the possible importance of SAMHD1 proximity to the RTC for the restriction to occur will be assessed. In aim 3, a combination of biochemical/proteomic/reverse genetic approaches will be used to identify cellular proteins and post-translational modifications that control SAMHD1 function. Experiments in aim 4 wil characterize developmental profiles of SAMHD1-mediated inhibition of HIV-1 infection in myeloid cells during their in vitro differentiation from CD34+ progenitor cells, and the possible involvement of SAMHD1 in early post-entry blocks of HIV-1 infection in non-myeloid cells. The relative importance of SAMHD1 co-factors, identified in aim 3, in primary myeloid cels wil also be assessed. The knowledge gained from our studies could lead to the conception of new strategies to improve the immune response to HIV and/or prevent formation of long-lived HIV reservoirs in tissue macrophages, by manipulating the SAMHD1 pathway. PUBLIC HEALTH RELEVANCE: Cellular SAMHD1 protein inhibits HIV-1 infection of certain blood cells termed macrophages and dendritic cells, which cells play key roles in AIDS pathogenesis by providing virus reservoirs and orchestrating immune response to HIV-1 infection. The main goal of the proposed research is to understand precisely how SAMHD1 inhibits HIV-1 infection of these cells. This is expected to identify potential attractive new targts for therapeutic intervention, and suggest strategies to better protect these cells from HIV infection.

描述（由申请人提供）：巨噬细胞和树突状细胞在病毒感染中具有关键作用，提供了经常抵抗抗病毒疗法的病毒储层，并将其与抗病毒适应性免疫反应联系起来。人类免疫缺陷病毒1（HIV-1）无法转导树突状细胞，并且由于强大的早期入学后限制导致了病毒cDNA的积累，因此具有降低的巨噬细胞能力。该限制在很大程度上是由细胞SAMHD1蛋白介导的，其中突变导致AICARDI GOTIERES综合征（AGS），这是一种自身免疫性疾病，与激活具有内源性核酸引起的先天免疫反应有关。重要的是，SAMHD1的目标是通过HIV-2/SIVSM病毒的VPX蛋白降解，这与其在抑制灵长类动物慢病毒感染中的关键作用一致。这些发现表明，SAMHD1介导了策划对HIV感染的免疫反应的关键细胞类型中的有效限制，因此可以确定抗病毒疗法的长期结局。我们建议阐明控制和介导SAMHD1限制HIV感染的细胞和分子机制。 AIM 1中的实验将在病毒和基于细胞的分析的背景下定义SAMHD1蛋白的功能组织，并评估SAMHD1病毒学和细胞功能之间的关系。 AIM 2中的实验将评估SAMHD1如何干扰HIV-1 cDNA合成。我们的数据表明，SAMHD1脱氧核苷三磷酸三磷酸氢化酶（DNTPase）催化活性在CELS中受到调节，与其他细胞酶一样，在CELS中也是如此，并且本身不足以限制HIV感染。因此，在限制性和非限制性条件下的SAMHD1催化活性将是 将评估SAMHD1接近RTC的特征和可能发生的限制的重要性。在AIM 3中，将使用生化/蛋白质组学/反向遗传方法的组合来鉴定控制SAMHD1功能的细胞蛋白和翻译后修饰。 AIM 4中的实验表征了SAMHD1介导的在与CD34+祖细胞的体外分化过程中SAMHD1介导的HIV-1感染的抑制作用，以及SAMHD1可能参与非男性类细胞HIV-1感染的早期结构阻滞。在AIM 3中确定的SAMHD1副因素的相对重要性也将被评估。从我们的研究中获得的知识可能会导致新策略的概念，以改善对HIV的免疫反应和/或通过操纵SAMHD1途径来改善组织巨噬细胞中长寿命的HIV储量。 公共卫生相关性：细胞SAMHD1蛋白抑制某些称为巨噬细胞和树突状细胞的血细胞的HIV-1感染，这些细胞通过提供病毒储层并培根对HIV-1感染的免疫反应，在AIDS发病机理中起关键作用。拟议研究的主要目标是精确地了解SAMHD1如何抑制这些细胞的HIV-1感染。预计这将确定潜在的有吸引力的治疗干预新塔格，并提出更好地保护这些细胞免受HIV感染的策略。