Regulation of antiviral APOBEC3G and APOBEC3F by interferons

干扰素对抗病毒 APOBEC3G 和 APOBEC3F 的调节

• 批准号: 7229623
• 负责人: Xiao-Fang Yu
• 金额: $ 24.6万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-20 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7229623
• 关键词: Antiviral Agents; CD4 Positive T Lymphocytes; Cell Line; Cells; Cultured Cells; Cytidine Deaminase; Disease; Genes; Genetic Transcription; Goals; HIV-1; Hepatitis B Virus; Hepatocyte; Human; IRF1 gene; Individual; Inflammation; Interferon-alpha; Interferons; Janus kinase; Knowledge; Literature; Mediating; Mediator of activation protein; Molecular; Natural Immunity; Nature; Pathway interactions; Patients; Peripheral Blood Mononuclear Cell; Personal Satisfaction; Play; Protein Family; Protein Overexpression; Proteins; Regulation; Relative (related person); Reporting; Research; Retroviridae; Role; STAT1 protein; STAT2 gene; Serum; Signal Pathway; Transcriptional Activation; Transcriptional Regulation; Up-Regulation; Variant; Viral; Viral Load result; Viral Physiology; Virus; Work; acrosome stabilizing factor; base; cell type; cytokine; in vivo; insight; macrophage; novel; research study; response; vif Gene Products

DESCRIPTION (provided by applicant): APOBEC3G (A3G) and related APOBEC3F (A3F) have broad anti-viral activity against retroviruses and hepatitis B virus (HBV). However, their regulation in viral natural target cells such CD4+ T lymphocytes, macrophages, and primary liver cells have not been well-studied. Our long-term goal is to elucidate the role of A3G and ASF in IFN-mediated innate immunity. The specific hypothesis is that certain human cells may utilize a novel IFN-mediated signaling pathway to upregulate the A3G and ASF proteins in the defense against viruses. We base the hypothesis on the following observations. 1) We showed that A3G was upregulated by interferons (IFN) in a cell-type dependent manner. IFN-a induced A3G in macrophages, primary hepatocytes and liver cell lines. IFN-y also induced A3G in liver cells. Neither cytokine could upregulate A3G in primary CD4+ T cells, while other known IFN-stimulated genes (ISG) such as PKR and IRF-1 were induced in all three cell-types. 2) In macrophages and liver cell lines, IFN-a induction of A3G was dependent upon JAK kinases. While the canonical IFN-a JAK/STAT signaling pathway requires both STAT1 and STAT2, we observed that induction of A3G and certain other ISG by IFN-a in HepSB liver cells was STAT2-dependent but STAT1-independent. The proposed experiments will focus on determining the nature of IFN-mediated A3G antiviral activity in macrophages and characterizing the specific molecular signaling pathway of IFN induction of A3G in macrophages and liver cells. The specific aims are: Aim 1) to study the role of IFN-a induced A3G and A3F expression in anti-HIV-1 activity of these proteins in macrophages. We will investigate the antiviral effect of A3G on HIV-1 in macrophages upon induction by IFN-a. The experiments will determine if IFN induction of A3G will result in functional antiviral activity in macrophages. Aim 2) to further characterize the STAT1-independent pathway of IFN-a induction of A3G and other ISG in liver cells and macrophages. IFN-a STAT1-independent pathways of gene transcription have not been described. These experiments will define components involved in the transcriptional activation of A3G and ASF. While we have determined that JAK kinases are required to induce A3G, we will further characterize the involvement of other STAT family proteins as well as potential novel mediators. The proposed research should provide insight into the antiviral role that A3G and ASF play both in natural immunity and in response to IFN treatment. Furthermore, the work would potentially enhance knowledge of general IFN-mediated signaling pathways.

性状（申请人提供）：APOBEC 3 G（A3 G）和相关APOBEC 3 F（A3 F）对逆转录病毒和B型肝炎病毒（HBV）具有广泛的抗病毒活性。然而，它们在病毒天然靶细胞如CD 4 + T淋巴细胞、巨噬细胞和原代肝细胞中的调节尚未得到充分研究。我们的长期目标是阐明A3 G和ASF在IFN介导的先天免疫中的作用。具体的假设是，某些人类细胞可能利用一种新的IFN介导的信号通路来上调A3 G和ASF蛋白质以防御病毒。我们的假设基于以下观察。1)我们发现，A3 G是上调干扰素（IFN）在细胞类型依赖性的方式。IFN-α在巨噬细胞、原代肝细胞和肝细胞系中诱导A3 G。IFN-γ还诱导肝细胞中的A3 G。两种细胞因子都不能上调原代CD 4 + T细胞中的A3 G，而其他已知的IFN刺激基因（ISG）如PKR和IRF-1在所有三种细胞类型中均被诱导。2)在巨噬细胞和肝细胞系中，IFN-α诱导A3 G依赖于JAK激酶。虽然经典的IFN-α JAK/STAT信号传导途径需要STAT 1和STAT 2两者，但我们观察到在HepSB肝细胞中IFN-α对A3 G和某些其他ISG的诱导是STAT 2依赖性的，但不依赖于STAT 1。拟议的实验将集中在确定IFN介导的A3 G在巨噬细胞中的抗病毒活性的性质，并表征IFN诱导A3 G在巨噬细胞和肝细胞中的特定分子信号传导途径。目的1）研究IFN-α诱导的A3 G和A3 F表达在巨噬细胞抗HIV-1活性中的作用。我们将研究A3 G在IFN-α诱导下对巨噬细胞中HIV-1的抗病毒作用。实验将确定IFN诱导A3 G是否会导致巨噬细胞中的功能性抗病毒活性。目的2）进一步研究IFN-α诱导肝细胞和巨噬细胞中A3 G和其他ISG的STAT 1非依赖性途径。IFN-α STAT 1非依赖性的基因转录途径尚未被描述。这些实验将定义参与A3 G和ASF转录激活的组分。虽然我们已经确定JAK激酶是诱导A3 G所必需的，但我们将进一步表征其他STAT家族蛋白以及潜在的新型介质的参与。拟议的研究应该提供洞察A3 G和ASF在自然免疫和响应IFN治疗中发挥的抗病毒作用。此外，这项工作可能会增加一般干扰素介导的信号通路的知识。