One-step generation of T-cell receptor knock-in mice in the TCRβ locus.

Transgenic mouse models expressing predefined T-cell receptors (TCRs) have been instrumental in advancing our understanding of T-cell biology. However, these traditional models rely on random genomic insertion of large constructs, require labor-intensive embryo manipulation, and frequently result in aberrant TCR expression and phenotypes. These limitations render traditional models insufficient to meet the mounting demands for rapid and precise model systems to evaluate TCR specificities. In this study, we developed a streamlined method that uses adeno-associated virus (AAV) and CRISPR/Cas9-mediated genome editing to precisely integrate pre-rearranged TCRα/β sequences into the mouse TCRβ (Trb) locus, enabling the rapid generation of TCR knock-in mice with physiological TCR expression and functional T-cell differentiation upon antigenic challenge. This approach bypasses the need for screening multiple founders for faithful TCR expression, enhancing the versatility and utility of monoclonal TCR mice in basic immunology and preclinical research, such as in the fields of cancer immunotherapy and vaccine development.