OTK18 Regulation in HIV-1 associated dementia

描述(由申请人提供)：转录因子OTK18最近被我们的小组证明可以调节单核吞噬细胞(MP)中的HIV-1感染。有趣的是，OTK18在重症HIV-1脑炎患者脑MP胞浆中特异表达，而在重症HIV-1脑炎患者中不表达 其他神经退行性疾病，因此可作为艾滋病毒相关痴呆(HAD)发展的“替代”标记物。为了进一步发展这些观察，我们将确定为什么OTK18在晚期疾病中可以相对较高的水平表达，但却无法控制脑靶细胞中的病毒生长。我们的初步数据表明，HIV-1长末端重复序列的E-26-1结合序列(EBS)是抑制OTK18的关键元件。EBS也位于OTK18启动子的近端区域，提示基因表达的自我抑制机制。在这一应用中，我们假设EBS结合与OTK18内切酶一起调节HAD中OTK18的活性。此外，我们将解决OTK18在疾病中的高水平之间的差异。以及它的抗逆转录病毒功能。 我们认为这种明显的矛盾是由于感染的巨噬细胞中OTK18的内切蛋白裂解导致其细胞质定位和病毒逃避OTK18的抑制。在这种背景下，病毒逃避OTK18抑制将与HAD相关。为了检验这些假设，我们将提出以下问题：1)HIV-1诱导OTK18表达的机制(S)是什么？2)病毒抑制OTK18的机制是什么？以及3)OTK18内切的机制是什么？我们认为，OTK18的分子特征将有助于更好地理解MP病毒调节的双重复杂作用及其在HIV-1感染的神经发病中的作用。我们将解决以下具体目标：1)研究启动子元件在OTK-18功能中的作用。2)研究HAD中病毒逃避OTK18抑制的机制；3)研究OTK18的加工和功能。这项拟议的研究是创新的，因为通过锌更精细的蛋白调节病毒并通过EBS突变逃避OTK18抑制是一种新的范式。我们的 这些发现也可能对锌指分子领域产生重要影响，因为OTK18位于染色体19q13上，在该染色体上有多个逆转录病毒整合位点和锌指 进化上的共同本地化。

DESCRIPTION (provided by applicant): The transcriptional factor, OTK18, has recently been shown by our group to regulate HIV-1 infection in mononuclear phagocytes (MP). Interestingly, OTK18 is specifically expressed in the cytosol of brain MP in severe HIV-1 encephalitis but not in other neurodegenerative disorders and may thus serve as a "surrogate" marker for the development of HIV-associated dementia (HAD). To further develop these observations we will determine why OTK18 can be expressed at relatively high levels in advanced disease and yet fail to control viral growth in brain target cells. Our preliminary data indicates that the E-twenty six-1 binding sequence (EBS) of the HIV-1 long termminal repeat is a critical element for OTK18 suppression. EBS is also located in the proximal region of the OTK18 promoter, suggesting an autoinhibitory mechanism of gene expression. In this application, we hypothesize that EBS binding along with OTK18 endoproteolysis regulate OTK18 activity in HAD. Furthermore, we will address the discrepency between high OTK18 levels in disease. and its anti-retroviral functions. We believe this apparent contradiction to be due to endoproteolytic cleavage of OTK18 in infected macrophages leading to its cytoplasmic localization and viral escape from OTK18 suppression. In that context, viral escape from OTK18 suppression will correlate with HAD. To examine these hypotheses, the following questions will be asked:1) What is the mechanism(s) for HIV-1 induction of OTK18 expression?, 2) What is the mechanism of viral from OTK18 suppression in HAD?, and 3) What is the mechanism of OTK18 endoproteolysis? We posit that molecular characterization of OTK18 will lead to a better understanding of the dual complex roles of MP viral regulation and its role in the neuropathogensis of HIV-1 infection. We will address the following specific aims; 1) To study the role of promoter elements in OTK-18 function. 2) To study the mechanism of viral escape from OTK18 suppression in HAD, and 3) To characterize OTK18 processing and function. The proposed research is innovative, as viral regulation by a zinc finer protein and escape from OTK18 suppression by EBS mutation is a new paradigm. Our findings may also have an important impact in the field of zinc finger molecules, since OTK18 is located on chromosome 19q13, where clusters of retroviral integration sites and zinc fingers are evolutionally co-localized.