Artificial antigen-presenting cells are superior to dendritic cells at inducing antigen-specific cytotoxic T lymphocytes

•Antigen-specific cytotoxic T lymphocytes are the main executors of transformed cells during cancer immunotherapy.•Dendritic cells based antigen-specific cytotoxic T lymphocytes inductions are complex, requiring numerous cytokines and extended times for cell expansion.•Artificial antigen-presenting cells have been proposed as a promising alternative to autologous dendritic cells to stimulate antigen-specific cytotoxic T lymphocytes.•This study demonstrates that K562 cells based artificial antigen-presenting cells promote the induction of antigen-specific cytotoxic T lymphocytes with a less differentiated “young” phenotype and superior cytotoxic effector characteristics in vitro. Adoptive immunotherapy is a promising cancer treatment that entails infusion of immune cells manipulated to have antitumor specificity, in vitro. Antigen-specific cytotoxic T lymphocytes are the main executors of transformed cells during cancer immunotherapy. To induce antigen-specific cytotoxic T lymphocytes, we developed artificial antigen-presenting cells (aAPCs) by engineering K562 cells with electroporation to direct the stable expression of HLA-A∗0201, CD80, and 4-1BBL. Our findings demonstrate that after three stimulation cycles, the aAPCs promoted the induction of antigen-specific cytotoxic T lymphocytes with a less differentiated “young” phenotype, which enhanced immune responses with superior cytotoxicity. This novel, easy, and cost-effective approach to inducing antigen-specific cytotoxic T lymphocytes provides the possibility of improved cancer therapies.