Inhibitors of host kinases as molecular targets for immune defense against HIV-1

宿主激酶抑制剂作为 HIV-1 免疫防御的分子靶点

基本信息

批准号：
8702919
负责人：
Mathias Lichterfeld
金额：
$ 43.5万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-08-01 至 2015-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8702919
关键词：
ALVAC Acute Affect B-Lymphocytes Biochemical Biological Assay Biological Models CD4 Positive T Lymphocytes Cells Cellular Assay Clinical Communicable Diseases Consensus Cyclin-Dependent Kinases Data Defense Mechanisms Disease Disease remission Enzymes Epigenetic Process Evaluation Family Genetic Transcription Goals HIV HIV vaccine HIV-1 Highly Active Antiretroviral Therapy Host resistance Human Immune Immunologics Immunologist Infection Infection prevention Integration Host Factors Intercept Investigation Life Cycle Stages Mediating Messenger RNA MicroRNAs Molecular Molecular Profiling Molecular Target Molecular and Cellular Biology Monitor Pathogenesis Pathway interactions Patients Pattern Peripheral Blood Mononuclear Cell Persons Pharmaceutical Preparations Phosphotransferases Physicians Physiological Predisposition Prevention strategy Process Protein Biochemistry Proteins Proviruses RNA-Directed DNA Polymerase Regulation Resistance Reverse Transcription Sampling Scientist Testing Time Transcript Up-Regulation Viral Viral Load result Virus base cell mediated immune response cohort experience in vivo inhibitor/antagonist innovation novel oncoprotein p21 pathogen patient population prevent

项目摘要

DESCRIPTION (provided by applicant): Elite controllers are HIV-1 infected persons with undetectable viral loads in the absence of HAART, and the identification of immune defense mechanisms in these patients may reveal critical new information for increasing immune defense against HIV-1 in a broader HIV-1 patient population. Previous studies in elite controllers have mostly focused on classical T- and B-cell mediated immune responses against HIV-1. However, it has been shown that such adaptive immune activity may not be a sufficient, and sometimes not even a necessary component of effective immune protection against HIV-1 in these patients. In preliminary studies, we found that CD4 T cells from elite controllers are substantially less susceptible to HIV-1 replication. This partial resistance of CD4 T cells from elite controllers was mediated by a strong upregulation of the cyclin- dependent kinase inhibitor p21 (waf-1/cip-1), which was able to independently suppress HIV-1 reverse transcription and mRNA transcription. To our knowledge, these data represent the first description of a molecular HIV-1 restriction factor that actively inhibits HIV-1 replication in vivo in elite controllers and an therefore serve as a direct molecular target for enhancing host resistance to HIV-1. Here, we propose to extend our investigations of p21-mediated HIV-1 restriction by strategically focusing on three specific aims: To analyze molecular pathways responsible for the protective high-level expression of p21 in CD4 T cells from elite controllers, we will investigate how miRNAs regulate p21 gene transcription in CD4 T cells, using longitudinal samples collected from a unique cohort of HIV-1 elite controllers for whom PBMC samples are available from the time of acute infection (specific aim 1). In specific aim 2, we propose to mechanistically investigate how p21 affects HIV-1 reverse transcription, one of the earliest and most important HIV-1 replication steps. We hypothesize that p21 can indirectly inhibit HIV-1 reverse transcriptase by blocking host proteins from the cyclin-dependent kinase family that activate reverse transcriptase. If these studies are successful, we will identify a new aspect of HIV-1 host-pathogen interactions that can intercept an early HIV-1 replication step and may therefore be particularly attractive for clinical approaches to increase host resistance to HIV-1. Finally, we will mechanistically investigate how p21 may contribute to mechanisms of HIV-1 latency by affecting host factors involved in transcriptional elongation of HIV-1 mRNA transcripts; these investigations may provide important new information for inducing a long-term drug-free remission of HIV-1 infection by preventing viral outgrowth from latently infected cells (specific aim 3). Overall, these studies represent a highly interdisciplinary investigation integrating immunologic, virologic and biochemical approaches for the mechanistic investigation of a novel HIV-1 restriction factor that is effective at limiting the susceptibility to HIV-1 infection in vivo in elite controllers; if sucessful, these studies will reveal important new information for HIV-1 pathogenesis, immune defense and clinical strategies for prevention and treatment of HIV-1 infection.

描述（由申请人提供）：精英控制者是在没有HAART的情况下病毒载量无法检测到的HIV-1感染者，识别这些患者的免疫防御机制可能会揭示关键的新信息，以增强对HIV-1的免疫防御。更广泛的 HIV-1 患者群体。之前针对精英控制者的研究主要集中在针对 HIV-1 的经典 T 细胞和 B 细胞介导的免疫反应。然而，已经表明，这种适应性免疫活性可能不足以，有时甚至不是这些患者针对 HIV-1 的有效免疫保护的必要组成部分。在初步研究中，我们发现来自精英控制者的 CD4 T 细胞对 HIV-1 复制的敏感性大大降低。 CD4 T 细胞对精英控制者的这种部分抵抗是由细胞周期蛋白依赖性激酶抑制剂 p21 (waf-1/cip-1) 的强烈上调介导的，p21 能够独立抑制 HIV-1 逆转录和 mRNA 转录。据我们所知，这些数据代表了对分子 HIV-1 限制因子的首次描述，该因子在精英控制者体内主动抑制 HIV-1 体内复制，因此可作为增强宿主对 HIV-1 抵抗力的直接分子靶标。在这里，我们建议通过战略性地关注三个具体目标来扩展我们对 p21 介导的 HIV-1 限制的研究：为了分析负责精英控制者 CD4 T 细胞中 p21 保护性高水平表达的分子途径，我们将研究如何miRNA 调节 CD4 T 细胞中的 p21 基因转录，使用的是从一组独特的 HIV-1 精英控制者中收集的纵向样本，这些控制者从急性感染时就可以获得 PBMC 样本（具体目标 1）。在具体目标 2 中，我们建议从机制上研究 p21 如何影响 HIV-1 逆转录，这是最早也是最重要的 HIV-1 复制步骤之一。我们假设 p21 可以通过阻断激活逆转录酶的细胞周期蛋白依赖性激酶家族的宿主蛋白来间接抑制 HIV-1 逆转录酶。如果这些研究成功，我们将确定 HIV-1 宿主与病原体相互作用的一个新方面，它可以拦截早期 HIV-1 复制步骤，因此可能对提高宿主对 HIV-1 抵抗力的临床方法特别有吸引力。最后，我们将从机制上研究p21如何通过影响参与HIV-1 mRNA转录本转录延伸的宿主因子来促进HIV-1潜伏机制；这些研究可能提供重要的新信息，通过防止潜伏感染细胞的病毒生长，诱导 HIV-1 感染的长期无药物缓解（具体目标 3）。总体而言，这些研究代表了一项高度跨学科的研究，整合了免疫学、病毒学和生化方法，对一种新型 HIV-1 限制因子进行机制研究，该因子可有效限制精英控制者体内对 HIV-1 感染的易感性；如果成功，这些研究将揭示有关 HIV-1 发病机制、免疫防御以及预防和治疗 HIV-1 感染的临床策略的重要新信息。