A preparation of autologous T-lymphocytes that have been genetically engineered to express a T-cell Antigen Coupler (TAC), comprised of a domain that targets the tumor-associated antigen (TAA) claudin 18.2 (CLDN18.2; A2 isoform of claudin-18) and another domain that binds to the endogenous T-cell receptor (TCR), with potential immunostimulating and antineoplastic activities. Upon administration, autologous anti-CLDN18.2 TAC T-cells TAC01-CLDN18.2 target and bind to CLDN18.2-expressing tumor cells and activate TCR-mediated signaling pathways, leading to T-cell-mediated killing of CLDN18.2-expressing tumor cells. CLDN18.2, a tight junction protein and stomach-specific isoform of claudin-18, is expressed on a variety of tumor cells. Its expression in healthy tissues is strictly confined to short-lived differentiated epithelial cells of the gastric mucosa.