Luo Feiyang, Yao Qiwen, Hao Yanan, Shen Meiying, Chen Tong, Wu Ruixin, Li Tingting, Han Xiaojian, Jin Aishun
Department of Immunology, School of Basic Medical Sciences, Chongqing Medical University, Chongqing 400010, China; Chongqing Key Laboratory of Tumor Immune Regulation and Immune Intervention, Chongqing Medical University, Chongqing 400010, China.
Department of Breast and Thyroid Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.
Cell Immunol. 2025 Aug;414:104999. doi: 10.1016/j.cellimm.2025.104999. Epub 2025 Jun 23.
Engineered T cell receptors (TCRs) targeting neoantigens represent a transformative approach in cancer immunotherapy, yet their clinical potential is limited by low natural TCR avidity and the risk of off-target toxicity from over-engineered TCRs with excessive high-affinity. Here, we developed a TCR engineering platform to enhance the functional avidity of a TCR targeting the KRAS G12D mutation (KRAS) while avoiding reactivity to the wild-type (WT) peptide. We separately constructed CDR3α- and CDR3β-focused TCR libraries derived from an HLA-A*11:01-restricted KRAS-specific TCR and screened them using alternating positive and negative selection: KRAS-pulsed antigen-presenting cells (APCs) drove functional avidity, while KRAS-pulsed APCs eliminated cross-reactive clones. From these libraries, we identified CDR3α variants with modest avidity gains and reduced off-target reactivity, and CDR3β variants with significant avidity enhancement and potent tumor cytotoxicity, albeit with variable cross-reactivity profiles. This strategy enables precision engineering of neoantigen-specific TCRs, balancing therapeutic efficacy and safety for adoptive transfer TCR-T therapy.
靶向新抗原的工程化T细胞受体（TCR）代表了癌症免疫治疗中的一种变革性方法，但其临床潜力受到天然TCR亲和力低以及过度工程化的高亲和力TCR存在脱靶毒性风险的限制。在此，我们开发了一种TCR工程平台，以增强靶向KRAS G12D突变（KRAS）的TCR的功能亲和力，同时避免对野生型（WT）肽产生反应性。我们分别构建了源自HLA-A*11:01限制性KRAS特异性TCR的聚焦CDR3α和CDR3β的TCR文库，并使用交替的阳性和阴性选择对其进行筛选：KRAS脉冲抗原呈递细胞（APC）驱动功能亲和力，而KRAS脉冲APC消除交叉反应性克隆。从这些文库中，我们鉴定出亲和力适度增加且脱靶反应性降低的CDR3α变体，以及亲和力显著增强且具有强大肿瘤细胞毒性的CDR3β变体，尽管其交叉反应性谱各不相同。该策略能够对新抗原特异性TCR进行精准工程设计，为过继性转移TCR-T疗法平衡治疗效果和安全性。
