MECHANISMS OF MUTATIONS & HYPERMUTATIONS IN RETROVIRUSES

突变机制

• 批准号: 3460679
• 负责人: VINAY K. PATHAK
• 金额: $ 10.15万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-01 至 1997-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3460679
• 关键词: 2'3' dideoxycytidine; 2'3' dideoxyinosine; DNA replication; RNA directed DNA polymerase; Retroviridae; biological models; chickens; drug resistance; gene mutation; mutant; virus genetics; virus replication; zidovudine

DESCRIPTION (Adapted from the applicant's abstract): The goal of this project is to understand the molecular and biological mechanisms that generate variation in retroviral populations.Variation in retroviral populations has become medically important because it generates drug- resistant human immuno-deficiency (HIV) variants, allows the virus to evade the host immune response, and may frustrate efforts to develop anti-retroviral vaccines. Mutations in retroviruses are also essential for activating the oncogenic potential of proto-oncogenes captured by retroviruses. A clinically relevant aim is to use the spleen necrosis virus (SNV)-based in vivo forward mutation assay to determine whether anti-retroviral drugs AZT, ddI and ddC increase the retroviral mutation rate and contribute to the generation of drug-resistant virus. A related aim is to select for drug-resistant SNV and determine whether the mutant reverse transcriptases have altered mutation rates. Virus producing cells or target cells will be exposed to the drugs to determine whether they are mutagenic during viral RNA transcription or reverse transcription. SNV vectors will be designed to distinguish spontaneous as well as drug- induced mutations during RNA- or DNA-dependent DNA synthesis stages of reverse transcription. A second aim is to further understand the process we named hypermutation, in which several mutations occur in each provirus during one round of retroviral replication. The frequency and types of hypermutation will be determined by using retroviral vectors designed to identify hypermutation. Our hypothesis that hypermutation results from polymerization by error-prone reverse transcriptases will be tested by utilizing a retroviral vector designed to identify and isolate genes encoding hypermutant reverse transcriptases. A third aim is to perform the forward mutation assay in an animal model system to determine the mutation rates in a single replication cycle, determine the replication rate for SNV in various stages of infection, and determine the relative replication rate for a wildtype and defective virus in co-infected animals to determine the evolutionary potential of retroviruses with transduced oncogenes.

描述（根据申请人的摘要改编）：目的 项目是要了解分子和生物学机制 在逆转录病毒种群中产生变化。逆转录病毒变化 种群在医学上变得重要，因为它会产生药物 - 抗性人免疫缺陷（HIV）变体使病毒得以实现 逃避宿主的免疫反应，并可能挫败发展的努力 抗逆转录病毒疫苗。逆转录病毒中的突变也是必不可少的 用于激活由原始基因的致癌潜力 逆转录病毒。 临床上相关的目的是使用基于脾脏坏死病毒（SNV） 体内正向突变测定法确定抗逆转录病毒药物是否是否 AZT，DDI和DDC提高了逆转录病毒突变率，并有助于 耐药病毒的产生。 相关的目的是选择 耐药性SNV并确定突变体是否反向 转录酶的突变率改变。 产生细胞的病毒或 靶细胞将暴露于药物中，以确定它们是否是 病毒RNA转录或逆转录过程中的诱变。 SNV 向量将设计为区分自发和药物 在RNA或DNA依赖性DNA合成阶段的诱导突变 逆转录。 第二个目的是进一步了解我们命名过超名的过程， 在一轮一轮中，每个病毒中发生了几个突变 逆转录病毒复制。 超名的频率和类型将 通过使用设计识别的逆转录病毒载体确定 超名。 我们假设超名是由 通过容易出错的逆转录酶聚合将通过 利用设计和隔离基因的逆转录病毒载体 编码超重逆转录酶。 第三个目的是在动物模型中执行正向突变测定法 在单个复制周期中确定突变率的系统， 确定在感染的各个阶段SNV的复制率， 并确定野生型和缺陷的相对复制率 共同感染的动物中的病毒，以确定 带有转导的癌基因的逆转录病毒。