靶向 KRAS(G12D) 癌症新抗原的 T 细胞受体的功能性亲和力增强

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 G12D ) while avoiding reactivity to the wild-type (WT) peptide.

We separately constructed CDR3 - and CDR3 -focused TCR libraries derived from an HLA-A*11:01-restricted KRAS G12D -specific TCR and screened them using alternating positive and negative selection: KRAS G12D -pulsed antigen-presenting cells (APCs) drove functional avidity, while KRAS WT -pulsed APCs eliminated cross-reactive clones.

From these libraries, we identified CDR3 variants with modest avidity gains and reduced off-target reactivity, and CDR3 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.