Effects of cocaine on miRNAs that regulate HIV-1 replication

描述(申请人提供)：完全静止的CD4+T细胞是不允许HIV-1复制的，只有激活的细胞才支持高水平的病毒复制。在静息细胞中，病毒进入并不限制感染，而是复制周期中进入后的一些步骤是有缺陷的。这些缺陷很可能是细胞辅助因子水平有限的结果。我们建议检验这样一个假设，即静止的CD4+T细胞中的一些限制性辅助因子受到miRNA抑制，当T细胞激活时，这种抑制被解除，导致辅助因子的表达和允许HIV-1复制的细胞环境。MiRNAs是一种短的(~22个核苷酸)的RNA，它与靶mRNAs形成不完全的双链，并抑制翻译。MiRNAs通常针对其目标mRNAs的3‘非编码区。我们最近的工作为这一假设提供了强有力的支持，即静止的CD4+T细胞中的miRNAs抑制了一种名为Cyclin T1的HIV-1辅助因子。我们建议详细研究静止的CD4+T细胞中Cyclin T1的miRNA抑制作用。我们还建议确定在这些细胞中受到miRNA抑制的其他辅助因子mRNAs。此外，艾滋病毒感染者使用可卡因与更快地发展为艾滋病有关。可卡因刺激HIV-1复制，并已被证明改变细胞mRNAs和miRNAs的表达模式。我们将检验这一假设，即可卡因刺激HIV-1复制涉及与HIV-1复制相关的miRNAs表达水平的变化。我们用miR-27b和miR-223这两个可以抑制Cyclin T1的miRNAs的初步数据为这一假说提供了初步支持。拟议研究的完成将为限制HIV-1在静止的CD4+T细胞中复制的机制提供新的见解，以及对可卡因促进病毒复制的机制的洞察。这一见解在设计新的治疗方法来治疗艾滋病毒-1感染方面应该是有价值的，特别是在有可卡因滥用史的个人中。与公共卫生相关：我们将确定调控HIV-1复制的非编码小RNA，我们还将确定可卡因是否影响这些RNA的水平。我们的研究可能会改善患者的治疗，并增加对可卡因使用如何加速艾滋病进展的理解。

DESCRIPTION (provided by applicant): Fully resting CD4+ T cells are non-permissive for HIV-1 replication and only activated cells support high levels of viral replication. In resting cells, viral entry is not limiting for infection, but rather a number of post-entry steps in the replication cycle are defective. These defects are likely to be the result of limiting levels of cellular co-factors. We propose to test the hypothesis that some of these limiting co-factors in resting CD4+ T cells are subject to miRNA repression, and upon T cell activation this repression is relieved, leading to expression of the co-factors and a permissive cellular environment for HIV-1 replication. MiRNAs are short (~22 nucleotide) RNAs that form imperfect duplexes with target mRNAs and repress translation. MiRNAs typically target the 3' UTR of their target mRNAs. Our recent work has provided strong support for the hypothesis that miRNAs in resting CD4+ T cells repress an HIV-1 co-factor known as Cyclin T1. We propose to investigate in detail miRNA repression of Cyclin T1 in resting CD4+ T cells. We also propose to identify other co-factor mRNAs that are subject to miRNA repression in these cells. Additionally, the use of cocaine by HIV-infected individuals is associated with a more rapid progression to AIDS. Cocaine stimulates HIV-1 replication and it has been shown to alter the expression pattern of cellular mRNAs and miRNAs. We will test the hypothesis that cocaine's stimulation of HIV-1 replication involves changes in expression levels of miRNAs of relevance to HIV-1 replication. Our preliminary data with miR-27b and miR-223, miRNAs that can repress Cyclin T1, have provided initial support for this hypothesis. Completion of the proposed research will provide new insight into mechanisms that restrict HIV-1 replication in resting CD4+ T cells, as well as insight into mechanisms whereby cocaine enhances viral replication. This insight should be valuable in designing new therapeutic approaches to treat HIV-1 infection, especially in individuals with a history of cocaine abuse. PUBLIC HEALTH RELEVANCE: We will identify small non-coding RNAs that regulate HIV-1 replication, and we will also determine if cocaine affects the levels of these RNAs. Our research may improve patient treatment and increase understanding about how cocaine use accelerates progress to AIDS.