The in vivo function of A3A and A3G during retrovirus infection

A3A和A3G在逆转录病毒感染过程中的体内功能

• 批准号: 8456554
• 负责人: Spyridon Stavrou
• 金额: $ 5.39万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8456554
• 关键词: Antiviral Agents; Anus; Apolipoproteins B; Cell Nucleus; Cells; Complex; Cytidine; Cytidine Deaminase; DNA; DNA Damage; Deamination; Drug resistance; Endogenous Retroviruses; Family; Family member; Gene Proteins; Generations; Genes; Genome; Goals; HIV-1; Human; In Vitro; Infection; Knock-out; Knockout Mice; Laboratories; Lead; Light; Longevity; Milk; Modeling; Mouse Mammary Tumor Virus; Movement; Murine leukemia virus; Mus; Mutation; Oncogenic; Papillomavirus; Parvovirus; Pennsylvania; Play; Protein Family; Proteins; Proviruses; Retroelements; Retrotransposition; Retroviridae; Retroviridae Infections; Rodent; Role; Single-Stranded DNA; Testing; Therapeutic; Training; Transgenic Mice; Universities; Uridine; Viral; Viral Pathogenesis; Virion; Virus; Virus Diseases; Zoonoses; Zoonotic Infection; drug resistant virus; in vivo; insight; mammalian genome; mouse model; novel therapeutics; prevent; public health relevance; response; tissue culture; transmission process; treatment strategy; tumorigenesis; viral DNA

DESCRIPTION (provided by applicant): Retroviruses can infect a variety of species, including humans. Retroviral DNA integrates into the genome, resulting in persistent infections. Mammalian genomes are also under constant threat by endogenous retroviruses and retroelements. They thus have developed multiple mechanisms to restrict retroviral infections prior to proviral integration. Among the host restriction factors are APOBEC3 proteins with cytidine deaminase activity (CDA) that act during retroviral replication and that inhibit retrotransposition. There are 7 human A3 (hA3) family members (A3A-A3H), while rodents have a single A3 gene. All A3 proteins have CDA domains and can convert cytidines to uridines in reverse-transcribed single-stranded DNA, resulting in mutation of the viral DNA. While the human A3 proteins have been extensively studied in tissue culture, little is known about their action in vivo. Here, I propose to use transgenic mice that I recently created and express 2 human A3 proteins, A3A and A3G, with the goal of determining their ability to restrict retroviruses in vivo. A3A has a potent role in restricting viruses and retroelement retrotransposition in vitro, while A3G inhibits retroviruses such as HIV-1. Moreover, it has been suggested that A3 proteins play a critical role in preventing zoonoses and indeed, several human A3 proteins have been shown to restrict mouse retroviruses in vitro. Because of their potent antiviral activity, increasing A3 activity is currently being investigated as a target of ani-viral therapy but whether this has the potential to lead to cellular DNA damage or to drug-resistant retroviruses is not known. We will thus use these transgenic mice to test their effects on mouse mammary tumor virus (MMTV) and murine leukemia virus (MLV) infection, retroviruses for which the mouse is the natural host and which are only partially restricted by mouse A3 (mA3). Our laboratory (Dr. Susan Ross' laboratory at the University of Pennsylvania) pioneered the use of genetically modified mice, including mA3 knockout mice, to study host-retrovirus interactions in vivo. Thus, this project will provide me with training in retroviruses ad the generation of transgenic mouse models, while drawing on my previous training in viral pathogenesis in mice. This study will provide insight into the function of the A3 proteins in vivo, and also has the potential to create new models for testing therapeutic strategies for treating retroviral infections in humans.

描述（由申请人提供）：逆转录病毒可以感染多种物种，包括人类。逆转录病毒 DNA 整合到基因组中，导致持续感染。哺乳动物基因组也不断受到内源逆转录病毒和逆转录因子的威胁。因此，他们开发了多种机制来在原病毒整合之前限制逆转录病毒感染。宿主限制因子包括具有胞苷脱氨酶活性 (CDA) 的 APOBEC3 蛋白，该蛋白在逆转录病毒复制过程中发挥作用并抑制逆转录转座。人类 A3 (hA3) 家族成员 (A3A-A3H) 有 7 个，而啮齿动物只有一个 A3 基因。所有A3蛋白都具有CDA结构域，可以将逆转录单链DNA中的胞苷转化为尿苷，导致病毒DNA突变。虽然人类 A3 蛋白已在组织培养中得到广泛研究，但对其体内作用却知之甚少。在这里，我建议使用我最近创建的表达 2 种人类 A3 蛋白 A3A 和 A3G 的转基因小鼠，目的是确定它们在体内限制逆转录病毒的能力。 A3A 在体外限制病毒和逆转录元件逆转录转座方面具有有效作用，而 A3G 则抑制 HIV-1 等逆转录病毒。此外，有人认为 A3 蛋白在预防人畜共患疾病方面发挥着关键作用，事实上，几种人类 A3 蛋白已被证明可以在体外限制小鼠逆转录病毒。由于其强大的抗病毒活性，目前正在研究增加 A3 活性作为抗病毒治疗的目标，但这是否有可能导致细胞 DNA 损伤或产生耐药逆转录病毒尚不清楚。因此，我们将使用这些转基因小鼠来测试它们对小鼠乳腺肿瘤病毒（MMTV）和小鼠白血病病毒（MLV）感染的影响，小鼠是逆转录病毒的天然宿主，并且仅部分受到小鼠A3（mA3）的限制。我们的实验室（宾夕法尼亚大学 Susan Ross 博士的实验室）率先使用转基因小鼠（包括 mA3 敲除小鼠）来研究体内宿主与逆转录病毒的相互作用。因此，该项目将为我提供逆转录病毒和转基因小鼠模型生成方面的培训，同时借鉴我之前在小鼠病毒发病机制方面的培训。这项研究将深入了解 A3 蛋白的体内功能， 并且还有可能创建新模型来测试治疗人类逆转录病毒感染的治疗策略。