Antibody Guided Cell-SELEX Technology

描述（由申请人提供）：天然存在的抗体（Ig）可以被认为是自然界优化的靶向分子，具有优雅的结构特征和显著的特异性。Ig-靶标相互作用还提供了对成功的分子探针的生物化学和结构特性的深入了解，并为治疗和成像的新型分子的创新设计提供了指导。正在研究核酸适体（基于核酸的抗体类似物）以开发用于癌症的治疗分子。为了将适体开发为成功的治疗分子，有必要产生针对已知特异性靶标的适体。目前，使用在细胞上过表达的蛋白质或作为纯化的蛋白质来选择靶特异性适体，当蛋白质在其天然环境中以其天然水平表达时，其可能不识别靶向表位。最近引入的细胞-SELEX方法允许在其天然状态下选择针对膜靶的适体。我们将介绍一种创新的和新的技术的基础上，细胞-SELEX方法，第一次，在这个建议中，这将允许选择适体特异性的pe确定的抗原决定簇的受体分子在其天然状态下，由抗体-抗原相互作用的指导。这种新技术的引入将具有重要意义，因为这种方法将改进现有的选择适体的方法，使其朝向具有抗体或配体的更广泛的细胞受体分子。我们将通过进行两种不同的适体选择来测试这项技术。这两个靶标是：（1）T细胞受体复合物（TCR）的预定表位，（2）B细胞受体复合物（BCR）的预定表位。选择的抗TCR和抗BCR适体将被工程化为基于DNA的“合成抗体”，其模拟双特异性和单特异性天然抗体。在这个项目完成后，我们将有（1）一个新的SELEX技术，以选择可以针对已知表位定制的适体，（2）一类新的基于DNA适体的合成抗体模拟物，将在疾病领域，如癌症和自身免疫性疾病的治疗应用。

DESCRIPTION (provided by applicant): Naturally occurring antibodies (Igs) can be considered as nature's optimized targeting molecule with elegant structural features and remarkable specificity. Ig-target interactions also provide insights into the biochemical and structural properties of a successful molecular probe and offer a guideline towards innovative design of novel molecules for therapy and imaging. Nucleic acid aptamers (nucleic acid based antibody analogues) are being investigated to develop therapeutic molecules for cancer. In order to develop aptamers as successful therapeutic molecules, it is necessary to generate aptamers for known specific targets. Currently, target specific aptamers are selected using over-expressed protein either on a cell or as a purified protein, which may not recognize the targeting epitope when the protein is expressed at its native levels, in its native environment. Recently introduced cell-SELEX method allows the selection of aptamers towards membrane targets at their native state. We will introduce an innovative and novel technology based on cell-SELEX method, for the first time, in this proposal, which will allow selection of aptamers specific for pe-determined epitopes of a receptor molecule in their native state, guided by antibody-antigen interactions. Introduction of this new technology will be of significant, because this method will improve the existing methodology of selecting aptamers towards a broader range of cell receptor molecules that have an antibody or a ligand. We will test this technology by conducting two different aptamer selections. These two targets are: (1) A pre-determined epitope of T-cell receptor complex (TCR), (2) A pre-determined epitope of B-cell receptor complex (BCR). Selected anti-TCR and anti-BCR aptamers will be engineered into DNA based "synthetic antibodies" that mimic bi- and mono-specific native antibodies. Upon completion of this project we will have (1) A new SELEX technology to select aptamers that can be customized towards a known epitope, (2) A new class of synthetic antibody mimics based on DNA aptamers that will have therapeutic applications in disease areas such as cancer and autoimmune diseases.