Strategies of lentivirus persistence

慢病毒持久化策略

• 批准号: 7576766
• 负责人: Susan Carpenter
• 金额: --
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7576766
• 关键词: Acute; Affect; Biological Assay; Cessation of life; Characteristics; Chronic; Clinical; Cytotoxic T-Lymphocytes; Disease; Disease Progression; Down-Regulation; Effectiveness; Epitopes; Equilibrium; Equine Infectious Anemia Virus; Equus caballus; Evolution; Exons; Face; Gagging; Genetic; Genetic Variation; Genotype; Glycoproteins; Goals; Growth; HIV vaccine; HIV-1; HIV-1 vaccine; Immune; Immune Targeting; Immune response; Immune system; In Vitro; Infection; Integral Membrane Protein; Kinetics; Lead; Lentivirus Infections; Maps; Measures; Modeling; Molecular; Mutation; Nuclear Export; Phase; Phenotype; Population; Predisposition; Production; Recombinants; Recrudescences; Relative (related person); Resistance; Role; Sampling; Solutions; Staging; Statistical Models; Structural Genes; Structure; Subfamily lentivirinae; Surface; Testing; Variant; Viral; Viral Genes; Viral Proteins; Viral load measurement; Virus; Virus Diseases; Virus Replication; base; cost; design; experience; fitness; genetic selection; in vivo; interest; killings; longitudinal analysis; neutralizing antibody; novel vaccines; protein expression; research study; rev Gene Products; success

DESCRIPTION (provided by applicant): The ability of lentiviruses to continually evolve and escape immune control is the central impediment in developing an effective vaccine for HIV. The proposed studies will use the well-characterized equine infectious anemia virus (EIAV) model to identify virus factors important in the evolution and selection of immune escape variants during progression of lentiviral disease. The lifelong persistence of virus in vivo is a function of its ability to evade immune recognition and elimination as well as its ability to replicate, i.e. its replicative capacity. The overall goal of these studies is to determine if changes in the host immune environment during progression of disease reproducibly select for virus variants with altered replicative capacity. Specifically, we propose test the hypothesis that genetic changes in Rev and SU during progression of disease contribute to evasion of broadly neutralizing antibody and CTL at a cost in virus replicative capacity. The first aim will determine if env/rev genotypes that predominate at sequential stages of EIAV disease differ in replication phenotype. Infectious clones containing dominant env/rev genotypes representative of each stage of disease will be tested for replicative capacity in growth kinetic and growth competition assays, and the relative fitness of pairs of variants will be estimated. The second aim will determine the impact of variation in Rev and SU on replicative capacity and immune evasion. The replication phenotype of Rev will be quantified as nuclear export activity, and used to infer an immune evasion phenotype based on sensitivity to CTL killing. The SU replication and immune evasion phenotypes will be measured as infectivity and sensitivity to neutralizing antibody, respectively. These values, together with the replication fitness score obtained in Specific Aim 1, will be used in statistical models to determine which env/rev phenotypes affect changes in virus load during progression of disease. The third specific aim will use EIAV-based pseudovirus to identify specific molecular determinants of immune evasion and replication phenotypes. This will establish if there is a genetic link between escape from broadly neutralizing antibody and replicative capacity. In the fourth aim, in vivo competition assays will directly test the predictions of the statistical model developed in the second aim. Viruses containing env/rev genotypes that differ in immune evasion and/or replication phenotype will be inoculated into horses that have distinct immune environments with respect to EIAV, including: immunodeficient, naove, and convalescent. Following infection, dominant genotypes will be identified by quantitative RT-PCR and sequence analysis. These results will identify the relationship between immune evasion and replication phenotype and determine the respective roles of SU and Rev phenotype in EIAV selection under different immune environments in vivo. This detailed, integrative analyses will identify critical virus determinants of immune evasion and identify new vaccine targets that limit virus escape from broadly reactive immune responses. PUBLIC HEALTH RELEVANCE: Persistent virus infections are the etiological agents of AIDS and some cancers. The proposed studies will identify the genetic mechanisms that enable lentiviruses to modify their replication and thereby escape elimination by the host immune system. This strategy allows the virus to persist in vivo and, over time, acquire new mutations that leads to progression of clinical disease. The results of this study will identify new vaccine strategies for HIV-1 and persistent viruses that inhibit immune escape and prevent progression to AIDS and cancer.

描述（由申请人提供）：慢病毒不断发展和逃脱免疫控制的能力是开发艾滋病毒有效疫苗的核心障碍。拟议的研究将使用特征良好的马传染性贫血病毒（EIAV）模型来鉴定慢病毒疾病进展过程中免疫逃生变体的重要性和选择。病毒在体内的终生持久性是其逃避免疫识别和消除及其复制能力的能力，即其复制能力。这些研究的总体目标是确定疾病进展过程中宿主免疫环境的变化是否可重复选择具有改变能力的病毒变体。具体而言，我们提出了以下假设：疾病进展过程中Rev和SU的遗传变化有助于逃避广泛中和抗体和CTL，以病毒复制能力成本。第一个目的将确定在EIAV疾病的顺序阶段占主导的ENV/REV基因型在复制表型上是否有所不同。将测试代表每个疾病阶段的主要环境/REV基因型的传染性克隆，以测试生长动力学和生长竞争测定法的复制能力，并估计将估计各对变体的相对适应性。第二个目标将决定Rev和SU的变化对复制能力和免疫逃避的影响。 REV的复制表型将被定量为核输出活性，并用于根据对CTL杀戮的敏感性推断出免疫逃避表型。 SU复制和免疫逃避表型将分别以对中和抗体的感染性和敏感性来衡量。这些值以及在特定目标1中获得的复制适应性评分将在统计模型中使用，以确定哪些ENV/REV表型会影响疾病进展过程中病毒负荷的变化。第三个特定目的将使用基于EIAV的假病毒来识别免疫逃避和复制表型的特定分子决定因素。这将确定是否逃脱了广泛中和抗体和复制能力之间存在遗传联系。在第四个目标中，体内竞争分析将直接测试第二个目标中开发的统计模型的预测。在免疫逃避和/或复制表型上含有ENV/REV基因型的病毒将被接种到具有EIAV相对于EIAV的不同免疫环境的马匹，包括：免疫缺陷，NAOVE和康复。感染后，将通过定量RT-PCR和序列分析来鉴定主要的基因型。这些结果将确定免疫逃避和复制表型之间的关系，并确定体内不同免疫环境下SU和REV表型在EIAV选择中的各自作用。这种详细的综合分析将识别免疫逃避的关键病毒决定因素，并确定限制病毒逃避广泛反应性免疫反应的新疫苗靶标。 公共卫生相关性：持续性病毒感染是艾滋病和一些癌症的病因学药。拟议的研究将确定能够慢病毒修改其复制并从而逃脱宿主免疫系统的遗传机制。该策略使病毒能够在体内持续存在，并且随着时间的流逝，该病毒获得了导致临床疾病进展的新突变。这项研究的结果将确定针对HIV-1的新疫苗策略和持续性病毒，以抑制免疫逃脱并防止艾滋病和癌症的发展。