Large-scale generation of IL12 secreting macrophages from human pluripotent stem cells for cancer therapy

Genetically engineered macrophages (GEMs) have emerged as an appealing strategy to treat cancers, but are largely impeded by the cell availability and technical challenges in gene transfer. Here, we develop an efficient approach to generate large-scale macrophages from human induced pluripotent stem cells (hiPSCs). Starting with 1 T150 dish of 10⁶ hiPSCs, more than 10⁹ mature macrophages (iMacs) could be generated within 1 month. The generated iMacs exhibit typical macrophage properties such as phagocytosis and polarization. We then generate hiPSCs integrated with an IL12 expression cassette in AAVS1 locus to produce iMacs secreting IL12, a strong pro-immunity cytokine. hiPSCs derived iMacs_IL12 prevent cytotoxic T cell exhaustion and activate T cells to kill different cancer cells. Furthermore, iMACs_IL12 display strong anti-tumor effects in a T cell dependent manner in subcutaneously or systemically xenografted mice of human lung cancer. Therefore, we provide an off-the-shelf strategy to produce large-scale GEMs for cancer therapy.