Effect of novel cdk9 inhibitor on HIV transcription

描述：自20世纪90年代中期出现有效的联合抗逆转录病毒疗法以来，其安全性和耐受性的改善以及新药物和新类别的出现简化了艾滋病毒的治疗，使治疗更有可能取得成功。我们对维持长期病毒学抑制所需的治疗依从性程度以及与艾滋病毒感染和治疗相关的一些主要不良事件的病理生理学的理解都有所改善。针对艾滋病毒编码酶的抗逆转录病毒药物减缓了艾滋病的死亡率，但到目前为止还没有开发出有效的疫苗，也没有实际的治疗方法。今天，人们普遍认为，艾滋病毒-1治疗的成功将需要靶向其他艾滋病毒和/或宿主细胞蛋白。HIV-1转录是最有希望的阶段，没有药物存在。转录是调节HIV-1潜伏期的核心，因此，利用能够靶向该启动子的抑制剂具有重要意义。事实上，如果开发出一种有效的艾滋病毒转录抑制物，它可以被认为是治疗艾滋病的功能性药物。我们研究的长期目标是了解在活跃和潜伏感染期间如何抑制HIV-1基因组的表达。我们的短期目标将针对了解CDK9抑制剂如何能够选择性地抑制HIV-1启动子的机制细节。我们的假设是，了解TAT如何与一种仅存在于HIV-1感染细胞中的小形式P-TEFb相互作用，将为开发更好的抗病毒药物提供靶点 这将阻止HIV-1基因的表达。本项目的目的是阐明CDK9抑制剂在潜伏感染的T细胞中有效维持静止转录状态的机制。我们进行这些研究的理由是基于大量的初步数据，这些数据证明了感染细胞中存在独特的P-TEFb复合体，并利用潜伏细胞系统和动物模型对其进行了抑制。这些目标包括：通过体外转录实验确定TAT特异性P-TEFb(CDK9/T1)复合体的抑制作用机制；使用我们的抑制剂和体内研究来确定TAT特异性P-TEFb(CDK9/T1)复合体对染色质HIV DNA的靶点；将利用任何细胞毒性分析来确定任何潜在的副作用；以及CR8#13对HIV-1潜伏模型和人源化小鼠NSG模型的影响。总而言之，这些研究将确定CR8#13如何潜在地有助于人类的长期转录记忆(即启动子的甲基化)和抑制病毒。

DESCRIPTION: Since the advent of potent combination antiretroviral therapy in the mid-1990s, improvements in its safety and tolerability and the emergence of new agents and classes has simplified treatment of HIV and made treatment success more likely. Our understanding of both the degree of treatment adherence needed to maintain long-term virological suppression and the pathophysiology of some of the major adverse events associated with HIV infection and therapy has improved. Anti-retroviral drugs targeting HIV encoded enzymes have slowed the death rate from AIDS but to date no effective vaccines have been developed and there is no practical cure. Today it is widely believed that the success in HIV-1 treatment will require targeting of other HIV and/or host cellular proteins. HIV-1 transcription is the most promising stage for which no drugs exist. Transcription is at the heart of regulating HIV-1 latency and, therefore, utilizing inhibitors that can target this promoter is significant. In fact, if an effectve inhibitor of HIV transcription was developed it could be considered a functional cure for AIDS. The long-term goal of our research is to understand how expression of the HIV-1 genome can be inhibited during active and latent infection. Our short term goals will be directed toward understanding mechanistic details of how a cdk9 inhibitor is able to selectively inhibit HIV -1 promoter. Our hypothesis is that understanding how Tat interfaces with a small form of P-TEFb, that is present only in HIV-1 infected cells, will provide targets for developing better antivirals that will block HIV-1 gene expression. The objective of this project is to elucidate the mechanisms used by a cdk9 inhibitor that can effectively maintain a quiescent transcriptional state in latently infected T cells. Our rationale for these studies is based on mounting preliminar data demonstrating the presence of unique P-TEFb complex in infected cells and its inhibition using latent cell systems and animal models. The aims include: defining mechanism of inhibition using in vitro transcription assay to define targets of Tat-specific P-TEFb (cdk9/T1) complex on the chromatin HIV DNA with our inhibitor and in vivo studies that will assess any cellular toxicity Assays will be utilized to define any potential side effects; and the effect of CR8#13 on HIV-1 latent models as well as humanized mouse NSG model. Collectively, these studies will define how CR8#13 can potentially contribute to long lasting transcriptional memory (i.e., methylation of the promoter) and suppression of virus in humans.