Bi-specific Aptamers Mediating Tumor Cell Lysis
Bi-specific Aptamers Mediating Tumor Cell Lysis
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DOI：
10.1074/jbc.m111.238261
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发表时间：
2011-06-17
影响因子：
4.8
通讯作者：
Hock, Bjoern
中科院分区：
文献类型：
--
作者：
Boltz, Achim;Piater, Birgit;Hock, Bjoern
抗体依赖性细胞毒性在基于抗体的肿瘤治疗中发挥着关键作用，其基础是通过 Fc γ 受体 III (CD16) 的结合将自然杀伤细胞招募到抗体结合的肿瘤细胞中。在这里，我们描述了同时结合 CD16 α 和 c-Met（一种在许多肿瘤中过度表达的受体）的嵌合 DNA 适体的生成。通过应用指数富集配体系统进化 (SELEX) 方法，分离出 CD16 α 特异性 DNA 适体，其以高特异性和亲和力 (91 pM-195 nM) 与其各自的重组和细胞表达的靶蛋白结合。使用不同的接头将两个优化的 CD16 α 特异性适体与两个 c-Met 特异性适体中的每一个偶联。双特异性适体保留了适当的结合特性并显示出与两种抗原的同时结合。此外，它们介导依赖于适体和效应细胞浓度的细胞毒性。用竞争性抗体 3G8 置换 CD16 α 的双特异性适体降低了细胞毒性，并证实了所提出的作用模式。这些结果代表了两种不同寡核苷酸通过连接成介导细胞毒性的双特异性适体而首次获得肿瘤有效功能。
Antibody-dependent cellular cytotoxicity plays a pivotal role in antibody-based tumor therapies and is based on the recruitment of natural killer cells to antibody-bound tumor cells via binding of the Fc gamma receptor III (CD16). Here we describe the generation of chimeric DNA aptamers that simultaneously bind to CD16 alpha and c-Met, a receptor that is overexpressed in many tumors. By application of the systematic evolution of ligands by exponential enrichment (SELEX) method, CD16 alpha specific DNA aptamers were isolated that bound with high specificity and affinity (91 pM-195 nM) to their respective recombinant and cellularly expressed target proteins. Two optimized CD16 alpha specific aptamers were coupled to each of two c-Met specific aptamers using different linkers. Bi-specific aptamers retained suitable binding properties and displayed simultaneous binding to both antigens. Moreover, they mediated cellular cytotoxicity dependent on aptamer and effector cell concentration. Displacement of a bi-specific aptamer from CD16 alpha by competing antibody 3G8 reduced cytotoxicity and confirmed the proposed mode of action. These results represent the first gain of a tumor-effective function of two distinct oligonucleotides by linkage into a bi-specific aptamer mediating cellular cytotoxicity.