Affinity maturation of T-cell receptor-like antibodies for Wilms tumor 1 peptide greatly enhances therapeutic potential.
Affinity maturation of T-cell receptor-like antibodies for Wilms tumor 1 peptide greatly enhances therapeutic potential.
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DOI：
10.1038/leu.2015.125
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发表时间：
2015-11
期刊：
影响因子：
11.4
通讯作者：
Cheung NK
中科院分区：
文献类型：
--
作者：
Zhao Q;Ahmed M;Tassev DV;Hasan A;Kuo TY;Guo HF;O'Reilly RJ;Cheung NK
WT 1126（RMFPNAPYL）是一种人类白细胞抗原-A2（HLA-A2）限制性肽，来源于Wilms肿瘤蛋白1（WT 1），广泛表达于广泛的白血病、淋巴瘤和实体瘤。从人源单链抗体库中筛选到一株特异性针对WT 1/HLA-A2复合物T细胞表位的TCR样单链抗体。该scFv通过诱变结合酵母展示进行亲和力成熟，并使用同源模型进行结构分析。该单价scFv显示出100倍的亲和力改善（解离常数（KD）=3 nm）和针对其靶向表位或HLA-A2+/WT 1+肿瘤细胞的精确特异性。双价scFv-huIgG 1-Fc融合蛋白表现出与T细胞表位和肿瘤靶标结合的甚至更高的亲合力（KD=2 μ m），并且能够介导表达嵌合抗原受体的人T或NK-92-MI转染细胞的抗体依赖性细胞介导的细胞毒性或肿瘤溶解。该抗体在体内对HLA-A2限制的WT 1阳性白血病异种移植物表现出特异性和有效的细胞毒性。总之，T细胞表位可以为基于抗体的治疗提供新的靶标。通过结合噬菌体和酵母展示以及scFv-Fc融合平台，可以快速探索用于开发高亲和力TCR样抗体的策略以用于潜在的临床开发。本文的在线版本（doi：10.1038/leu.2015.125）包含补充材料，可供授权用户使用。
WT1126 (RMFPNAPYL) is a human leukocyte antigen-A2 (HLA-A2)-restricted peptide derived from Wilms tumor protein 1 (WT1), which is widely expressed in a broad spectrum of leukemias, lymphomas and solid tumors. A novel T-cell-receptor (TCR)-like single-chain variable fragment (scFv) antibody specific for the T-cell epitope consisting of the WT1/HLA-A2 complex was isolated from a human scFv phage library. This scFv was affinity-matured by mutagenesis combined with yeast display and structurally analyzed using a homology model. This monovalent scFv showed a 100-fold affinity improvement (dissociation constant (KD)=3 nm) and exquisite specificity towards its targeted epitope or HLA-A2+/WT1+ tumor cells. Bivalent scFv-huIgG1-Fc fusion protein demonstrated an even higher avidity (KD=2 pm) binding to the T-cell epitope and to tumor targets and was capable of mediating antibody-dependent cell-mediated cytotoxicity or tumor lysis by chimeric antigen receptor-expressing human T- or NK-92-MI-transfected cells. This antibody demonstrated specific and potent cytotoxicity in vivo towards WT1-positive leukemia xenograft that was HLA-A2 restricted. In summary, T-cell epitopes can provide novel targets for antibody-based therapeutics. By combining phage and yeast displays and scFv-Fc fusion platforms, a strategy for developing high-affinity TCR-like antibodies could be rapidly explored for potential clinical development. The online version of this article (doi:10.1038/leu.2015.125) contains supplementary material, which is available to authorized users.