Regulation of SAMHD1 antiviral activity

SAMHD1 抗病毒活性的调节

基本信息

批准号：
10082845
负责人：
Felipe Diaz-Griffero
金额：
$ 57.64万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-20 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10082845
关键词：
Acetylation Amino Acids Anti-Retroviral Agents Antiviral Agents Binding Biochemical CD4 Positive T Lymphocytes Cessation of life Consequentialism Data Dendritic Cells Detection Development Enzymes Exhibits Genes HIV Infections HIV-1 HIV-2 Human Human Herpesvirus 2 Immune In Vitro Infection Infection prevention Innate Immune Response Innate Immune System Institution Interferon Type I Interferons Knockout Mice Knowledge Laboratories Life Cycle Stages Limb structure Mediating Medical Mutation Natural Immunity Nucleic Acid Binding Nucleic Acids Nucleotides Paralysed Patients Phenotype Phosphorylation Preventive vaccine Privatization Property Proteins Publishing RNA Regulation Reporting Research Personnel Resistance Rest Reverse Transcription Role Structure Subfamily lentivirinae T-Lymphocyte Testing Therapeutic Treatment Protocols Viral Virus Virus Diseases base in vivo innate immune function interest macrophage mutant new therapeutic target novel prevent pseudotoxoplasmosis syndrome resistant strain response sensor tool transmission process tripolyphosphate viral DNA viral RNA

项目摘要

Project Summary/Abstract Expression of the recently discovered human restriction factor SAMHD1 is responsible for the infection block imposed to lentiviruses such as HIV-1, HIV-2 and SIVmac by primary macrophages, dendritic cells and resting CD4+ T-cells. SAMHD1 blocks lentiviral infection by preventing the occurrence of reverse transcription. SAMHD1 has deoxynucleotide triphosphohydrolase (dNTPase) activity, which degrades deoxynucleotide triphosphates (dNTPs) into nucleotides and triphosphates, and this activity is required for HIV-1 restriction. However, additional studies have revealed that the dNTPase activity of SAMHD1 is not sufficient for HIV-1 restriction. Thus, an additional property of SAMHD1 is required for HIV-1 restriction. SAMHD1 interacts with nucleic acids in vitro, but the contribution of this interaction to HIV-1 restriction in vivo remains to be determined. Our preliminary data using SAMHD1 mutants indicate that nucleic acid binding is important for HIV-1 restriction. We determined the structure of SAMHD1 bound to an oligodeoxynucleotide and leveraged this structure as a tool for structure-function studies. Several amino acids form the interface between SAMHD1 and the oligodeoxynucleotide, and mutation of these residues resulted in SAMHD1 proteins that are unable to restrict HIV-1. These results suggest that the ability of SAMHD1 to interact with nucleic acids is important for HIV-1 restriction. Separate from its antiviral activity, mutations in the human SAMHD1 gene cause Aicardi- Goutières syndrome (AGS). AGS patients exhibit increased levels of type I interferon (IFN) that are believed to result from the recognition of endogenous nucleic acids by innate immune sensors. Thus, it has been suggested that the in vivo role of SAMHD1 is to prevent activation of the innate immune response by endogenous nucleic acids, and the nucleic acid binding activity of SAMHD1 has been suggested to be important for this function. Our preliminary data indicate that SAMHD1 knockout (KO) mice are resistant to herpes simplex virus 2 (HSV-2)-induced limb paralysis and death. These results suggest that SAMHD1 prevents the recognition of HSV-2 by innate immune sensors, potentially by interacting with the HSV-2 viral DNA and shielding it from detection. This strong phenotype in vivo will be used to unveil the role of SAMHD1 in innate immunity. Based on these published and preliminary results, the central hypothesis of this proposal is that the interaction of SAMHD1 with nucleic acids is important for its antiviral and innate immune functions. Our rationale is that identification of the mechanisms by which SAMHD1 modulates viral infection and innate immune responses will enable the development of novel antiviral and AGS therapies. To test our central hypothesis, we will pursue the following specific aims: 1) Determine the mechanism by which SAMHD1 inhibits HIV-1 infection, 2) Evaluate the role of SAMHD1 acetylation in SAMHD1-mediated viral restriction, and 3) Characterize the role of SAMHD1 in innate immunity.

项目摘要/摘要最近发现的人类限制因子SAMHD1的表达是导致感染的原因由原代巨噬细胞，树突状细胞和静止的CD4+ T细胞。 SAMHD1通过防止发生逆转录的发生来阻止慢病毒感染。 SAMHD1具有脱氧核苷酸三磷酶（DNTPase）活性，该活性降解了脱氧核苷酸三磷酸（DNTP）进入核苷酸和三磷酸盐，HIV-1限制是必需的。但是，其他研究表明，SAMHD1的DNTPase活性不足以用于HIV-1 限制。这是HIV-1限制所需的SAMHD1的额外属性。 SAMHD1与体外核酸，但是这种相互作用对体内HIV-1限制的贡献仍然是决定。我们使用SAMHD1突变体的初步数据表明，核酸结合对于 HIV-1限制。我们确定了与寡脱氧核苷酸结合的SAMHD1的结构并利用该结构是结构功能研究的工具。几种氨基酸形成SAMHD1之间的界面以及这些残差的寡脱氧核苷酸以及这些残留物的突变导致SAMHD1蛋白无法限制HIV-1。这些结果表明，SAMHD1与核酸相互作用的能力对于 HIV-1限制。与其抗病毒活性分开，人类SAMHD1基因的突变引起aicardi- Goutières综合征（AGS）。 AGS患者表现出据信的I型干扰素（IFN）的水平增加由先天免疫传感器识别内源性核酸的原因。那是建议SAMHD1的体内作用是防止通过内源性核酸以及SAMHD1的核酸结合活性已被认为是对于此功能很重要。我们的初步数据表明SAMHD1敲除（KO）小鼠对单纯疱疹病毒2（HSV-2）诱导的肢体瘫痪和死亡。这些结果表明SAMHD1 通过与HSV-2病毒相互作用，可以防止先天免疫传感器对HSV-2的识别 DNA并将其屏蔽到检测中。这种强大的体内表型将用于揭示samhd1在先天免疫。基于这些已发表的初步结果，该提案的中心假设是SAMHD1与核酸的相互作用对于其抗病毒和先天免疫很重要功能。我们的理由是识别SAMHD1调节病毒感染的机制先天免疫反应将使新型抗病毒和AGS疗法的发展。测试我们的中心假设，我们将追求以下特定目的：1）确定SAMHD1的机制抑制HIV-1感染，2）评估SAMHD1乙酰化在SAMHD1介导的病毒限制中的作用，并评估 3）表征SAMHD1在先天免疫中的作用。