Car-γδ T Cells Targeting Claudin18.2 Show Superior Cytotoxicity Against Solid Tumor Compared to Traditional Car-αβ T Cells

Background: Claudin18.2 (CLDN18.2) is highly expressed during the development of various malignant tumors, especially gastric cancer, and CAR-T cell targeting CLDN18.2 have therapeutic potential. However, their dependence on the major histocompatibility complex (MHC) for antigen recognition limits their application. Human Gamma Delta (γδ) T cells, with strong MHC-independent cytotoxicity to most solid tumors both in vivo and in vitro, are emerging as ideal cells for the generation of robust universal CLDN18.2 CAR-T cell to treat solid tumors. Our aim was to construct a universal CAR-γδ T cell targeting CLDN18.2. Methods: We constructed novel CAR-CLDN18.2-γδ T cell by lentiviral infection and compared their superior efficacy in the treatment of CLDN18.2-positive solid tumors in vivo and in vitro. Results: CD3ζ expression was verified in HEK293T cells after lentiviral transfection of CLDN18.2 CAR, and the lentivirus was packaged and concentrated to a titer of 4.90*108 TU/mL. Primary γδ T cells and αβ T cells were infected with efficiencies of approximately 31.76±4.122% and 44.13±4.436%, respectively. CAR-CLDN18.2-γδ T cells exhibited specific cytotoxicity against CLDN18.2-positive gastric cancer cells and secreted relatively high levels of Granzyme-B, Perforin-1 and IFN-γ. CAR-γδ T cells also showed superior cytotoxicity to target cells compared to classical CAR-αβ T cell in vitro. Finally, the antitumor activity of γδ T-CAR-CLDN18.2 cells were evaluated in tumor-bearing NSG mice, and CAR-CLDN18.2-γδ T cells significantly inhibited tumor growth and prolonged the survival of the mice. Conclusions: Our results demonstrate that universal CAR-CLDN18.2-γδ T cell is promising for the treatment of CLDN18.2-positive solid tumor and provide insights for the development of more universal CAR-γδ T-cell strategies for tumor immunotherapy.