TRANSMISSION AND VIRAL DYMANICS OF DRUG RESISTANT HIV-1

这项提案的总体目标是定义和了解控制多重耐药HIV-1的传播、适合性和体内复制动态的病毒学决定因素。对来自所有三种可用药物类别的单个药物的抗药性途径已经得到了很好的描述。耐药的分子基础发生在逆转录水平上，当突变发生时，在改变的蛋白质中表现为氨基酸替代，如蛋白酶和逆转录酶。最终，这导致HIV-1变种在抗病毒药物的强大选择压力下显示出生存优势。随着这些HIV-1变异株的进化并在接受治疗的社区中变得更加普遍，确定这些病毒是否正在传播以及如果传播的频率是多少，变得至关重要。为了解决这一问题，将通过对新感染者的病毒进行表型和基因分型分析来确定抗药性HIV-1传播的流行率。这对公共卫生具有相当重要的意义，因为抗药性病毒的传播将导致治疗方法的改变，并将证明对现有药物的病毒敏感性进行预测试是合理的。了解与传播有关的病毒适合性和复制能力的决定因素也是至关重要的。据推测，通过产生抗药性，该病毒在适应性和复制能力方面获得了“障碍”。然而，目前还不清楚这是否会影响传播性。为了确定导致耐药性的突变对传播性的影响，将构建抗药性重组病毒，并使用各种细胞靶点在体外表征它们的复制动力学，这些细胞靶点模拟发生传播的粘膜表面环境。最后，为了进一步了解多药耐药病毒的病毒动力学，将在体内进行介入研究，以推断耐药病毒在体内复制的参数。

The overall goal of this proposal is to define and understand the virologic determinants which govern the transmission, fitness, and in vivo replication dynamics of multi-drug resistant HIV-1. The pathway to resistance to individual agents from all three available drug classes has been well characterized. The molecular basis of drug resistance occurs at the level of reverse transcription, when mutations occur and are expressed as amino acid substitutions in altered proteins, such as protease and reverse transcriptase. Ultimately this results in an HIV-1 variant exhibiting a survival advantage in the presence of the strong selective pressure of antiviral agents. As these HIV-1 variants evolve and become more prevalent in the treated community, it becomes critical to determine whether these viruses are being transmitted, and if so in what frequency? To address this issue, the prevalence of resistant HIV-1 transmission will be determined using phenotypic and genotypic analysis of viruses from newly infected individuals. This is of considerable public health importance as the transmission of drug resistant viruses will result in changes in therapeutic practices and will justify pretreatment testing for virus susceptibility to available drugs. It is also critical to understand the determinants of virus fitness and replicative capacity as it relates to transmission. It is hypothesized that by becoming resistant the virus acquires a "handicap" in fitness and replicative capacity. However, it remains unknown whether this affects transmissibility. To determine the effects of resistance-conferring mutations on transmissibility, resistant recombinant viruses will be constructed and their replication kinetics characterized in vitro using a variety of cellular targets which simulate the environment of the mucosal surface at which transmission occurs. Finally, to further understand the viral dynamics of multi-drug resistant viruses, in vivo interventional studies will be performed in individuals to deduce parameters of drug resistant virus replication in vivo.