Antibody Guided Cell-SELEX Technology

描述(申请人提供)：天然抗体(IGs)可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着的特异性。免疫球蛋白-靶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洞察，并为创新设计用于治疗和成像的新型分子提供了指导。人们正在研究核酸适体(基于核酸的抗体类似物)，以开发治疗癌症的分子。为了开发适配子作为成功的治疗分子，有必要为已知的特定靶点产生适配子。目前，靶向特异性适配子的选择是利用在细胞上过度表达的蛋白或作为纯化的蛋白，当蛋白在其天然水平上表达时，在其天然环境中可能不识别靶向表位。最近引入的CELL-SELEX方法允许在天然状态下针对膜目标选择适配子。在这项提议中，我们将首次介绍一种基于细胞的创新和新颖的技术-SELEX方法，该方法将允许在抗体-抗原相互作用的指导下，针对天然状态下的受体分子的PE确定的表位选择特异性的适配子。这项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方法，即针对更广泛的具有抗体或配体的细胞受体分子选择适配子。我们将通过进行两种不同的适配子选择来测试这项技术。这两个靶点是：(1)T细胞受体复合体(TCR)的预定表位；(2)B细胞受体复合体(BCR)的预定表位。选定的抗TCR和抗BCR适配子将被改造成基于DNA的“合成抗体”，模仿双特异性和单特异性天然抗体。这个项目完成后，我们将拥有(1)一种新的SELEX技术来选择可以针对已知表位定制的适配子，(2)一种基于DNA适配子的新型合成抗体模拟物，它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.