Drug resistance mutations in the connection subdomain of the HIV-1 reverse transcriptase

人类免疫缺陷病毒1型（HIV-1）感染可以用抗逆转录病毒药物控制。在大多数接受抗逆转录病毒治疗的患者中，病毒发生突变，不再被药物抑制。耐药HIV-1的出现是导致患者失去药物疗效的主要因素之一。赋予耐药性的突变已经被定义，并且对不同的药物类别具有特异性。用于预测耐药性的基因型测定通常用于指导治疗HIV-1感染个体的治疗决策。对于靶向HIV-1逆转录酶（RT）的药物，常用的基因型试剂盒通常分析逆转录酶560个氨基酸中的前240个氨基酸的突变。这忽略了酶的其他区域突变的影响，这些区域在耐药性中可能很重要。最近，抑制HIV-1 RT的核糖核酸酶H功能的突变已被证明赋予对齐多夫定的高水平耐药性，提供了超过密码子240的突变可以赋予耐药性的先例。我们对核糖核酸酶H的不同区域（称为连接亚结构域）的分析表明，在药物治疗与药物初治患者中存在高度普遍的突变。在这项研究中，我们将使用体外试验来确定这些突变对耐药性和病毒适应性的影响。我们还将确定这些突变赋予耐药性的机制。最后，我们将使用我们独特的数据库，包括超过20，000个基因型样本，我们将确定这些突变在患者中的作用。这项研究预计将确定在RT连接子域中存在的具有临床意义的突变。此外，这项研究将导致更准确的基因型检测的发展，这将改善艾滋病毒感染者的临床管理。

Human immunodeficiency virus type 1 (HIV-1) infections can be controlled with antiretroviral drugs. In the majority of patients on antiretroviral therapy the virus mutates and is no longer inhibited by the drug. The emergence of drug-resistant HIV-1 is one of the major factors that lead to loss of drug efficacy in patients. Mutations that confer drug resistance have been defined and are specific for different drug classes. Genotype assays that are used to predict drug resistance are routinely used to guide therapeutic decisions in the treatment of HIV-1 infected individuals. For drugs that target the HIV-1 reverse transcriptase (RT), commonly used genotype kits normally analyse mutations in the first 240 out of 560 amino acids of the reverse transcriptase. This ignores the impact of mutations in other regions of the enzyme, which are potentially important in drug resistance. Recently, mutations that inhibit ribonuclease H function of the HIV-1 RT have been shown to confer high-level resistance to zidovudine, providing the precendent that mutations beyond codon 240 can confer drug resistance. Our analysis of a different region to ribonuclease H called the connection subdomain has demonstrated the presence of mutations that are highly prevalent in drug-treated versus drug naive patients. In this study we will use in vitro assays to define the effect of these mutations on drug resistance and viral fitness . We will also determine the mechanism by which these mutations confer drug resistance. Finally, using our unique database consisting of over 20,000 genotyped samples , we will establish the role of these mutations in the patient. This study is anticipated to identify clinically significant mutations that are present in the RT connection subdomain. Additionally, this study will lead to the development of more accurate genotype assays which will improve the clinical management of HIV infected individuals.