Origin and Evolution of HIV-1 Drug Resistance in the RT-SHIVmne Macaque Model

描述(由申请人提供)：HIV-1抗药性严重影响了感染者的治疗选择。建议使用至少包含两类药物的联合抗逆转录病毒疗法来治疗HIV-1感染。通常使用2个核苷类逆转录酶(RT)抑制剂(NRTI)和1个非核苷RT抑制剂(NNRTI)的组合。在治疗过程中，HIV-1可以获得突变，从而逃避抗逆转录病毒药物的抑制。耐药病毒可以在宿主内长期稳定，并可以水平或垂直传播给新的个体。然而，耐药的起源和个体内耐药的持久性还没有得到深入的研究。我们假设，耐药病毒将在血液中出现耐药性之前，在粘膜部位、中枢神经系统和淋巴结等组织中多部位出现，并与血液相比持续更长的时间。我们还提出，抗逆转录病毒药物在这些解剖区段的药代动力学和药效学的差异强烈地影响着耐药性的选择和持久性。非人灵长类动物模型在研究艾滋病的发病机制和免疫学方面很有用，使用的是猿猴免疫缺陷病毒(SIV)。因为NNRTI不抑制SIV，所以这些药物不能在SIV模型中进行研究。因此，我们建立了一种猕猴模型来研究HIV-1的体内耐药性。该模型使用感染了由含有HIV-1HxB2 RT编码区(RT-SHIVmne)的SIVmne组成的致病嵌合病毒的猕猴。在具体目标1中，我们建议纵向检查耐药RT-SHIVmne在血液和在NRTI或NNRTI单一治疗过程中出现的不同解剖间隔中的出现。由于艾滋病毒-1即使在抑制性抗逆转录病毒治疗期间仍存在于细胞和组织储存库中，我们在特定目标2中建议确定在停止单一治疗后以及在开始使用所有新药或包括在受感染动物的单一治疗中使用的药物的抗逆转录病毒治疗后，野生型病毒重新出现和耐药病毒持续存在的原因。为了探索耐药病毒出现的部位特异性差异是否由不同部位特异性药物浓度所解释，我们建议在特定目标3中检查治疗期间和治疗后抗逆转录病毒药物在血液和组织中的药代动力学和药效学。拟议的研究很难在人类身上执行，但可以很容易地在我们的抗逆转录病毒治疗和耐药性的RT-SHIVmne模型中执行。这些实验将为了解耐药性的解剖学来源、其在抗逆转录病毒治疗前后的持久性以及抗逆转录病毒药物动力学中部位特异性变异的影响提供新的见解。这项工作应该有助于确定更好的策略来治疗艾滋病毒感染者，特别是那些携带并可能传播抗药性病毒的人。 公共卫生相关性：这项建议中的研究旨在确定耐药艾滋病毒-1在宿主内的哪里发展。我们希望预测耐药病毒将在哪里以及如何出现，这将有助于我们更有效地进行靶向治疗，努力将耐药的发展和持久性降至最低。

DESCRIPTION (provided by applicant): HIV-1 drug resistance seriously impacts treatment options for infected individuals. It is recommended that HIV-1 infection be treated with combination antiretroviral therapy containing at least two classes of drugs. A combination of 2 nucleoside analog reverse transcriptase (RT) inhibitors (NRTIs) and 1 nonnucleoside RT inhibitor (NNRTI) is commonly used. During treatment, HIV-1 can acquire mutations that allow escape from inhibition by antiretroviral drugs. Drug resistant viruses can be stable within the host for long periods of time and can be transmitted horizontally or vertically to new individuals. However, the sites of origin and persistence of drug resistance within individuals over time has not been studied in depth. We hypothesize that drug resistant viruses will emerge multifocally in tissues, such as mucosal sites, the central nervous system, and lymph nodes, before resistance is seen in blood and will persist for longer periods of time as compared to blood. We also propose that differences in the pharmacokinetics and pharmacodynamics of antiretrovirals in these anatomic compartments strongly influence the selection and persistence of drug resistance. Nonhuman primate models have been useful in studying AIDS pathogenesis and immunology, using simian immunodeficiency virus (SIV). Because NNRTIs do not inhibit SIV, these drugs cannot be studied in the SIV model. Therefore, we developed a macaque model to study HIV-1 drug resistance in vivo. This model uses macaques infected with a pathogenic chimeric virus consisting of SIVmne containing the HIV-1HxB2 RT coding region (RT-SHIVmne). In Specific Aim 1, we propose to longitudinally examine the emergence of drug- resistant RT-SHIVmne in the blood and in different anatomical compartments that arise during NRTI or NNRTI monotherapy. Because HIV-1 persists in cellular and tissue reservoirs even during suppressive antiretroviral therapy, we propose in Specific Aim 2 to determine the origin of the re-emergence of wild-type virus and persistence of drug-resistant virus after discontinuation of monotherapy and after initiation of antiretroviral therapy using a regimen of all new drugs or one that includes the drug used in monotherapy in the infected animals. To explore whether site-specific differences in the emergence of drug resistant viruses are explained by different site-specific drug concentrations, we propose in Specific Aim 3 to examine the pharmacokinetics and pharmacodynamics of the antiretrovirals in the blood and tissues during and after therapy. The proposed studies are difficult to execute in humans but can be readily performed in our RT-SHIVmne model of antiretroviral therapy and drug resistance. These experiments will provide new insights into the anatomic origin of drug resistance, its persistence on and off antiretroviral therapy, and the influence of site- specific variation in antiretroviral pharmacokinetics. This work should help determine better strategies for treating HIV-infected individuals, particularly those harboring and potentially transmitting drug resistant virus. PUBLIC HEALTH RELEVANCE: The studies in this proposal are designed to determine where development of drug resistant HIV-1 occurs within the host. We hope to predict where and how resistant virus will emerge, which will help us to target therapy more effectively in an effort to minimize the development and persistence of drug resistance.