Determinates of anti-HIV nucleic acid aptamer potency and resistance

描述（由申请人提供）：需要新的治疗策略来规避耐药病毒的快速选择和当前抗hiv药物的毒性。靶向逆转录酶（RT）的RNA适体在细胞内表达时抑制病毒复制，它们在未来治疗HIV/AIDS方面具有很大的潜力。对于病毒如何在持续的选择压力下进化，或者如何改进适体以规避潜在的抗性，人们知之甚少。该项目的长期目标是开发RNA适体作为基因治疗药物，为快速进化的病毒提供长期抗病毒保护。我们的重点是确定RT氨基酸序列变化对适体抑制的影响，以及在体外和细胞中鉴定具有更好抑制作用的新适体序列和结构。目的1将确定适体识别的生物物理和结构基础，以及适体在系统发育不同的慢病毒RT中的差异抑制。目的2将鉴定具有广泛识别和提高效力的新适体，并描述与跨枝酶抑制相关的二级结构。目的3研究细胞内表达的适体对假型和复制能力的HIV-1的抑制作用，从控制表达、定位和抑制的设计元素的优化到适体和RT文库的高通量筛选。目的4评估适体抗性的从头进化，重点是建立遗传阈值，抗性位点和抗性的分子基础。该项目将评估HIV-1对核酸适体（一种很有前途的分子类型，最终将用于对抗HIV-1的基因治疗策略）抗性的潜力和性质，并将产生较少受逃逸突变影响的新适体。

DESCRIPTION (provided by applicant): New therapeutic strategies are needed to circumvent the rapid selection of drug resistant virus and the toxicity of current anti-HIV drugs. RNA aptamers targeted to the reverse transcriptase (RT) inhibit viral replication when expressed inside cells, and they offer great potential in future therapies against HIV/AIDS. There is little known about how the virus might evolve in the face of continual selection pressure, or about how the aptamers can be improved to circumvent potential resistance. The long-term goal of this project is to develop RNA aptamers as gene therapy agents that provide long-term antiviral protection against a rapidly-evolving virus. Our emphasis is on defining the influence of RT amino acid sequence variations on inhibition by aptamers, and on identifying new aptamer sequences and structures with improved inhibition, both in vitro and in cells. Aim 1 will determine the biophysical and structural basis for aptamer recognition and for differential inhibition by aptamers across phylogenetically diverse lentiviral RT's. Aim 2 will identify new aptamers with broad recognition and improved potency, and delineate the secondary structures associated with cross-clade enzymatic inhibition. Aim 3 examines inhibition of pseudotyped and replication-competent HIV-1 by intracellularly expressed aptamers, moving from optimization of the design elements that control expression, localization and inhibition to high throughput screens of aptamer and RT libraries. Aim 4 evaluates the de novo evolution of aptamer resistance with emphasis on establishing genetic threshold, resistance loci, and the molecular basis of resistance. PUBLIC HEALTH RELEVANCE This project will evaluate the potential for, and the nature of, HIV-1 resistance to nucleic acid aptamers-a promising class of molecules for eventual use in gene therapy strategies to combat HIV-1-and it will generate new aptamers that are less subject to escape mutations.