Antibody Guided Cell-SELEX Technology

描述（由申请人提供）：天然存在的抗体（Igs）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。igg -靶标相互作用还提供了对成功分子探针的生化和结构特性的见解，并为治疗和成像的新分子的创新设计提供了指导。核酸适体（基于核酸的抗体类似物）正在被研究用于开发治疗癌症的分子。为了使适配体成为成功的治疗分子，有必要针对已知的特定靶点生成适配体。目前，靶向特异性适配体是使用细胞上的过表达蛋白或纯化蛋白来选择的，当蛋白在其天然环境中以其天然水平表达时，这些蛋白可能无法识别靶向表位。最近引入的细胞selex方法允许选择适体对其天然状态的膜目标。我们将首次介绍一种基于细胞selex方法的创新技术，该技术将允许在抗体-抗原相互作用的指导下，在天然状态下选择特定于pe确定的受体分子表位的适体。这项新技术的引入将具有重要意义，因为该方法将改进现有的选择适体的方法，使其适用于更广泛的具有抗体或配体的细胞受体分子。我们将通过进行两个不同的适配体选择来测试该技术。这两个靶点分别是：(1)t细胞受体复合物（TCR）的预先确定表位，(2)b细胞受体复合物（BCR）的预先确定表位。选定的抗tcr和抗bcr适配体将被设计成基于DNA的“合成抗体”，模仿双特异性和单特异性的天然抗体。该项目完成后，我们将拥有(1)一种新的SELEX技术，用于选择可针对已知表位定制的适配体，(2)一类基于DNA适配体的新型合成抗体模拟物，将在癌症和自身免疫性疾病等疾病领域具有治疗应用。

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.