Retinoid Repression of HIV Through Chromatin Remodeling

描述（由申请人提供）：HIV-1感染导致免疫 宿主中的一种反应，被认为可以解决高水平的病毒血症 在感染的急性期发现。慢性感染是可能的 因为HIV-1已经进化到可以逃避宿主的免疫反应。一个战略 HIV-1使用的免疫逃避是建立潜伏感染。维生素 A代谢物，包括全反式维甲酸（RA），是天然的阻遏物 HIV 1表达，并可能在建立和维持 病毒潜伏期RA持续抑制HIV-1复制 巨噬细胞由细胞因子刺激，通常在高 浓度在当地网站，其中感染的巨噬细胞居住在体内， 本提案的总体目标是了解RA如何抑制HIV-1 表达，并确定这一过程中的作用，在潜伏期，RA抑制 HIV-1表达的抑制与重塑有关， 组蛋白H4超乙酰化的核小体定位在起始位点 HIV-1转录。这些结果，以及抑制需要的发现， 新的细胞蛋白质合成，支持假设RA诱导因子 与病毒启动子特异性结合， 染色质重塑本提案的目的是检验这一假设。 有两个具体目标。目标I的目标是评估RA的作用， 细胞因子激活的原代巨噬细胞中HIV-1复制的阻遏物， 为了确定抑制是否需要诱导特定的细胞 信号通路目的2的目标是评估RA作为一种 在已建立的细胞系中HIV-1染色质结构的调节剂， 主要细胞RA诱导的核小体结合的变化和 组蛋白的翻译后修饰将使用体内 核小体定位和足迹以及染色质免疫沉淀 测定。这些目标是描绘分子生物学的长期目标的一部分。 类维生素A介导的抑制机制和确定其治疗 潜力

DESCRIPTION (provided by applicant): HIV-1 infection leads to an immune response in the host that is thought to resolve the high levels of viremia found during the acute phase of infection. Chronic infections are possible because HIV-1 has evolved to evade the host immune response. One strategy of immune evasion used by HIV-1 is the establishment of latent infections. Vitamin A metabolites, including all-trans retinoic acid (RA), are natural repressors of HIV1 expression and may play a role in the establishment and maintenance of viral latency. RA consistently represses HIV-1 replication in primary macrophages that are stimulated by cytokines normally found in high concentrations at local sites, where infected macrophages reside in viva The overall goals of this proposal are to understand how RA represses HIV-1 expression and to determine the role of this process in latency, RA repression of HIV-1 expression is associated with an inhibition in the remodeling and histone H4 hyperacetylation of a nucleosome positioned at the start site of HIV-1 transcription. These results, and the finding that repression requires new cellular protein synthesis, support the hypothesis that RA induces a factor that specifically associates with the viral promoter and thereby prevents chromatin remodeling. The goal of this proposal is to test this hypothesis. There are two specific aims. The goal of aim I is to evaluate the role of RA as a repressor of HIV-1 replication in cytokine activated primary macrophages and to determine whether repression requires the induction of specific cellular signaling pathways. The goal of aim 2 is to evaluate the role of RA as an regulator of the HIV-1 chromatin structure in established cell lines and primary cells. RA-induced changes in nucleosome binding and the post-translational modification of histones will be examined using in vivo nucleosome mapping and footprinting as well as chromatin immunoprecipitation assays. These aims are part of the long term goal of delineating the molecular mechanisms of retinoid-mediated repression and determining their therapeutic potential.