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

描述（由申请人提供）：HIV-1耐药性严重影响感染者的治疗选择。建议HIV-1感染应采用至少包含两类药物的抗逆转录病毒联合治疗。通常使用2种核苷类逆转录酶（RT）抑制剂（NRTIs）和1种非核苷类逆转录酶抑制剂（NNRTI）的组合。在治疗期间，HIV-1可以获得突变，从而逃脱抗逆转录病毒药物的抑制。耐药病毒可以在宿主体内长时间保持稳定，并可以水平或垂直传播给新的个体。然而，个体耐药性的起源地点和持续时间尚未得到深入研究。我们假设耐药病毒在血液中出现耐药性之前会在组织中多灶出现，如粘膜部位、中枢神经系统和淋巴结，并且与血液相比，耐药病毒会持续更长的时间。我们还提出，这些解剖区室中抗逆转录病毒药物的药代动力学和药效学差异强烈影响耐药性的选择和持续。利用猿猴免疫缺陷病毒（SIV），非人灵长类动物模型在研究艾滋病发病机制和免疫学方面是有用的。由于NNRTIs不抑制SIV，这些药物不能在SIV模型中进行研究。因此，我们建立了猕猴模型来研究HIV-1在体内的耐药性。该模型使用感染了含有含有HIV-1HxB2 RT编码区（RT- shivmne）的SIVmne致病性嵌合病毒的猕猴。在Specific Aim 1中，我们建议纵向检查NRTI或NNRTI单药治疗期间血液和不同解剖室中出现的耐药RT-SHIVmne。由于HIV-1在细胞和组织储存库中持续存在，即使在抑制性抗逆转录病毒治疗期间，我们在特异性目标2中提出确定野生型病毒重新出现和耐药病毒持续存在的起源，在停止单一治疗后，在开始使用所有新药或包括在感染动物中使用的单一治疗药物的抗逆转录病毒治疗方案后。为了探索耐药病毒出现的位点特异性差异是否可以用不同的位点特异性药物浓度来解释，我们建议在特异性目标3中检查抗逆转录病毒药物在治疗期间和治疗后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体中进行，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模型中进行。这些实验将为耐药性的解剖学起源、抗逆转录病毒治疗前后耐药性的持续存在以及抗逆转录病毒药代动力学中位点特异性变异的影响提供新的见解。这项工作应有助于确定治疗艾滋病毒感染者的更好战略，特别是那些携带和可能传播耐药病毒的人。

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.