HER2 CAR-expressing iPSC-derived iNKT cells exhibit multifaceted immunomodulatory functions beyond direct tumor killing

Abstract

Background Autologous chimeric antigen receptor (CAR)-T cell therapy exhibits remarkable clinical efficacy for hematologic malignancies; however, its efficacy against solid tumors is limited by the immunosuppressive tumor microenvironment and the lack of effective strategies to induce broader antitumor immunity. Invariant natural killer T (iNKT) cells are known to elicit antitumor effects by activating tumor antigen-specific cytotoxic T lymphocytes, promoting dendritic cells maturation, and modulating macrophage activity, thereby providing a mechanism distinct from conventional T cell-based therapies. To couple this immunomodulatory capacity of iNKT cells with CAR technology, we developed allogeneic induced pluripotent stem cell (iPSC)-derived iNKT cells bearing a human epidermal growth factor receptor 2 (HER2) reactive CAR (HER2 CAR) and evaluated their cytotoxic and immunomodulatory functions. Method HER2 CAR-expressing iPSC-derived iNKT (HER2 CAR-ipsNKT) cells were generated and characterized for cytotoxic and immunomodulatory functions, including T-cell recruitment, and M2 macrophage re-polarization, and were evaluated for antitumor efficacy in xenograft mouse models. Results HER2 CAR-ipsNKT cells specifically recognized HER2-positive tumor cells and exerted potent antitumor activity through NK-like cytotoxicity. In addition to direct tumor killing, HER2 CAR-ipsNKT cells promoted the expansion of tumor-reactive T cells, and this effect was diminished following depletion of CD11c+ cells. HER2 CAR-ipsNKT cells also demonstrated immunomodulatory properties, including T-cell recruitment activity and M2 macrophage killing and re-polarization, supporting remodeling of the tumor immune microenvironment. Conclusion Our findings demonstrate that HER2 CAR-ipsNKT cells not only exert direct antitumor activity but also promote CD11c-dependent expansion of antigen-reactive CD8+ T cells, suggesting their capacity to induce broader antitumor immunity.