Towards therapy-induced lethal HIV mutagenesis

描述(申请人提供)：HIV-1疗法的局限性，包括病毒耐药性和非靶点效应，为确定新的药物靶点和开发新的抗HIV-1药物提供了动力。先前的体外数据发现，两种临床批准的药物地西他滨和吉西他滨联合使用，在单独使用时抗病毒活性最低的浓度下，HIV-1的传染性降低了73%。传染性的降低与突变频率的显著增加和HIV-1突变光谱的变化相吻合，这是通过将形成非正则碱基对的核苷类似物与某些核苷酸还原酶抑制剂相结合而实现的。突变负荷增加是抑制前病毒感染性后代病毒产生的主要抗病毒机制，并支持一种模型，即突变频率增加通过致死性突变降低传染性。在这个应用中，我们建议检验这样一个假设，即容易出错的病毒复制可能会在体内由于有害突变的积累而导致“错误灾难”或灭绝。旨在驱使病毒发生错误灾难的策略已被应用于HIV-1和一些RNA病毒，但在大多数情况下，它们尚未在体内评估其有效控制HIV复制的能力。在这里，我们建议使用一种新的人源化小鼠模型来研究1)地西他滨和吉西他滨在体内控制病毒复制的能力，以及2)地西他滨/吉西他滨药物组合通过提高病毒变异载量来控制体内HIV复制的能力。

DESCRIPTION (provided by applicant): The limitations of HIV-1 therapeutics, which include viral drug resistance and off-target effects, provide the impetus for the identification of novel drug targets and the development of new anti-HIV-1 drugs. Previous in vitro data found that the combination of two clinically approved drugs, decitabine and gemcitabine, reduced HIV-1 infectivity by 73% at concentrations that had minimal antiviral activity when used individually. Decreased infectivity coincided with a significant increase in mutant frequency and a shift in the HIV-1 mutant spectra by combining a nucleoside analog that forms non-canonical base pairs with certain ribonucleotide reductase inhibitors. Increased mutational load is implicated as the primary antiviral mechanism for inhibiting the generation of infectious progeny virus from provirus, and support a model in which increased mutation frequency decreases infectivity through lethal mutagenesis. In this application, we propose to test the hypothesis that error-prone viral replication may induce "error catastrophe" or extinction in vivo due to an accumulation of deleterious mutations. Strategies designed to drive viruses to error catastrophe have been applied to HIV-1 and a number of RNA viruses however for the most part they have not been evaluated in vivo for their ability to effectively control HIV replication. Here, we propose to use a novel humanized mouse model to investigate 1) the ability of decitabine and gemcitabine to control viral replication in vivo, and 2) the ability of the decitabine/gemcitabine drug combination to control HIV replication in vivo by elevating the viral mutational load.