Genetically engineered K562 cells augment NK cell cytotoxicity against acute myeloid leukemia and reduce dependency...

Acute myeloid leukemia (AML) is an aggressive malignancy with limited treatment options. Enhancing natural killer (NK) cell functionality through artificial antigen-presenting cells (aAPCs) represents a promising immunotherapeutic strategy. This study evaluates the potential of genetically modified K562 cells, expressing CD137L and CD86, to enhance NK cell-mediated cytotoxicity against AML cell lines (HL-60, KG-1, and THP-1). Lentiviral transduction was used to generate aAPCs, confirmed by PCR, RT-PCR, and flow cytometry. Cord NK cells and the NK-92 cell line were co-cultured with aAPCs, and their cytotoxicity against cell lines was assessed using 7-AAD staining. The ability of transduced K562 cells to substitute for interleukin-15 (IL-15) was also evaluated. These cells significantly enhanced NK cell-mediated cytotoxicity, with greater effects observed at higher effector-to-target (E:T) ratios. The aAPCs partially replaced IL-15 in activating cord blood NK cells but were ineffective for NK-92 cells. The aAPCs effectively enhance NK cell cytotoxicity and may reduce cytokine dependence in therapeutic applications. These findings highlight the potential of aAPCs to improve NK cell-based immunotherapies.