Role of Virus Recombination in Multiple Drug Resisitance

描述（由申请人提供）：人类免疫缺陷病毒（HIV）感染是全球五大死亡原因之一，对公共卫生构成重大威胁。通过使用抗逆转录病毒药物组合（高效抗逆转录病毒疗法），HAART在显著降低艾滋病毒相关死亡率和发病率方面有效。然而，近一半的艾滋病毒感染者仍然未能通过HAART治疗。尽管来自这些患者的病毒基因组的遗传分析显示pol基因中存在多重耐药突变，但耐药性出现的分子机制尚不清楚。因此，为了更有效地控制HIV感染，阐明多重阻力机制具有重要意义。在此，我们建议研究病毒重组在HAART过程中产生多重耐药的作用。我们建立了一个前瞻性临床队列，并开发了分析感染个体内重组病毒基因组的方法。该建议的具体目的是：(i)我们将在HAART治疗前对每位患者的多个克隆进行测序，从而对基线病毒群进行遗传表征，并确定其治疗失败的预测值。（ii）为了确定重组在产生多重耐药中的作用，我们将比较耐药病毒群与基线病毒群，并从HAART治疗失败的患者中确定重组基因组和重组指数增加。（iii）在连续HAART治疗方案中，我们将获得每次治疗失败前后的病毒种群，并分析病毒种群的动态变化，以确定反复耐药的机制和耐药病毒的适应度。了解HAART期间的病毒种群变化、耐药机制和病毒适应性将有助于开发更有效的抗逆转录病毒药物、更好的治疗方案和准确预测治疗效果。从这项研究中获得的知识可以广泛应用于理解病毒逃避免疫监视和其他选择性力的机制。

DESCRIPTION (provided by applicant): Human immunodeficiency virus (HIV) infection ranks among the top five causes of death globally and presents a major threat to public health. By using antiretroviral drug combination (Highly Active Antiretroviral Therapy), HAART has been effective in dramatically reducing HIV-related mortality and morbidity. However, nearly half of HIV-infected patients still fail HAART. Although genetic analyses of viral genomes from these patients show multiple-drug resistance mutations in the pol gene, the molecular mechanisms for the emergence of drug-resistance are not yet known. Therefore, it is important to delineate the mechanisms for multiple-drag resistance in order to more efficiently control HIV infection. Here, we propose to study the role of viral recombination in generation of multiple-drug resistance during HAART. We have established a prospective clinical cohort and developed methods to analyze recombinant viral genomes within an infected individual. Specific aims of this proposal are: (i) We will genetically characterize the baseline viral population and determine their predictive values for treatment failure by sequencing multiple clones from each patient before HAART treatment. (ii) To determine the role of recombination in generation of multiple-drug resistance, we will compare the drug-resistant viral population with the baseline viral population and identify recombinant genomes and recombinant index increase of the viral population from patients who fail HAART. (iii) We will obtain viral populations before and after each treatment failure in the consecutive HAART regimes and analyze the dynamic changes of viral populations to determine mechanisms of repeated drug-resistance and fitness of drug-resistance viruses. Understanding the viral population changes, drug-resistance mechanisms and viral fitness during HAART will allow for the development of more effective antiretroviral agents, better treatment regimens and accurate prediction of treatment efficacy. Knowledge obtained from this study can be broadly applied toward understanding mechanisms of viral escape from immune surveillance and other selective forces.