Engineering Nanoscale Aptamer-based Biomaterials that Target Cellular Receptors

描述(由申请人提供)：拟议工作的目标是开发和表征基于适配子的有效生物材料，这些材料基于一种仿生策略-多价识别宿主细胞受体。自然界利用多价相互作用，包括一个生物实体上的多个配体与另一个生物实体上的多个受体同时结合，以显著增强相互作用的亲和力。拟议的研究将使用多价性来开发和表征有效的异二价和多价杀菌剂，这些杀菌剂与CCR5受体结合，并防止由模式病原体HIV感染。尽管鸡尾酒抗逆转录病毒药物的使用对发达国家的艾滋病治疗产生了重大影响，但与这些方案相关的问题包括严重的副作用、高昂的成本和出现耐药菌株。在全球大流行的背景下，仍然迫切需要制定防止病毒传播的战略。鉴于缺乏有效的艾滋病毒疫苗，在性交前应用有效的杀微生物剂在感染确定之前阻止病毒仍然是我们阻止这种情况的最大希望。 短期内可怕的大流行。此外，这种制剂的活性成分必须是有效的、具有成本效益的，并解决出现病毒耐药性的问题。这项拟议工作的第一个目标是识别与CCR5不同结构域结合的短寡核苷酸适配子。第二个目标是优化基于适体的异二价和多价抑制剂的生物相容性和活性。第三个目的是利用一种新的人源化骨髓/肝脏/胸腺(HuBLT)小鼠模型来表征体内的抑制效果，并设计在较长时间内控制释放异二价和多价抑制剂的配方，以提高杀菌剂的可接受性。我们预计，这些新型的异二价和多价抑制剂将有效地阻止CCR5介导的HIV进入靶细胞。主动的异二价和多价CCR5靶向抑制剂应有助于解决对艾滋病毒抑制剂的抗药性这一重要问题，因为：CCR5是一个静态靶标，不容易出现艾滋病毒-1的高变异率；CCR5表达基因缺陷的人对感染艾滋病毒-1高度抵抗，但在其他方面是正常的健康个体；大多数艾滋病毒-1传播病例涉及使用CCR5进入的病毒株，在感染建立期间，这种株占主导地位。短适配子的使用将使这种方法从成本角度来看是可行的。提议的异二价和多价杀微生物剂代表了创新的新配方，它将多种干预措施(针对CCR5的不同胞外区域的配体)结合在一个分子内。我们预计，我们提议的研究计划将导致新的艾滋病毒杀菌剂具有更高的有效性、安全性和可接受性，为防止这种全球重要病原体的传播提供强有力的手段。

DESCRIPTION (provided by applicant): The objective of the proposed work is to develop and characterize potent aptamer-based biomaterials that recognize host cellular receptors based on a biomimetic strategy - polyvalency. Nature makes use of polyvalent interactions, involving the simultaneous binding of multiple ligands on one biological entity to multiple receptors on another, to strengthen the avidity of interactions significantly. The proposed studies will use polyvalency to develop and characterize potent heterodivalent and polyvalent microbicides that bind to CCR5 receptors and prevent infection by a model pathogen, HIV. Although the use of cocktails of antiretroviral drugs has had a major impact on the treatment of AIDS in the developed world, there are problems associated with these regimens including serious side effects, high costs, and the emergence of resistant strains. In the context of the global pandemic, there remains a critical need for strategies to prevent the transmission of the virus. Given the lack of an effective HIV vaccine, an effective microbicidal formulation applied prior to intercourse to block the virus before infection is established remains our best hope to arrest this terrible pandemic in the short term. Moreover, the active components of such formulations must be potent, cost effective, and address the problem of emergence of viral resistance. The first aim of the proposed work is to identify short oligonucleotide aptamers that bind to different domains of CCR5. The second aim is to optimize the biocompatibility and activity of aptamer-based heterodivalent and polyvalent inhibitors. The third aim is to characterize inhibitory efficac in vivo using a new humanized bone marrow/liver/thymus (huBLT) mouse model and to design formulations for the controlled release of the heterodivalent and polyvalent inhibitors over an extended period to improve microbicide acceptability. We anticipate that these novel heterodivalent and polyvalent inhibitors will effectively block CCR5-mediated entry of HIV into target cells. Active heterodivalent and polyvalent CCR5-targeted inhibitors should help address the important problem of resistance to HIV inhibitors because: CCR5 is a static target, not prone to the high mutation rate of HIV-1; persons with a genetic defect in CCR5 expression are highly resistant to infection with HIV-1, but are otherwise normal, healthy individuals; and most cases of HIV-1 transmission involve viral strains that use CCR5 for entry, and such strains predominate during the establishment of infection. The use of short aptamers will make the approach practical from a cost perspective. The proposed heterodivalent and polyvalent microbicides represent innovative new formulations that combine multiple interventions (ligands targeted towards different extracellular domains of CCR5) within a single molecule. We anticipate that our proposed research program will result in novel HIV microbicides with improved efficacy, safety, and acceptability, providing a powerful means to prevent the transmission of this globally-important pathogen.