... aAPCs-based expansion TILs K562 cells expressing CD64, CD137L and CD28 ligands CD80 and CD86, pulsed with anti-CD3 antibody efficiently activate and expand CD8+ CD28- T cells and antigen- specific T cells ... CD28 on T cells, enabling efficient polyclonal expansion of circulating T cells (50 to 1000-fold) over 10-14 days of ex vivo culture with preferential expansion of naïve and memory CD4+ T cells [10], ... sterility Artificial antigen presenting cells (aAPCs) expressing ligands for the T cell receptor and costimulatory molecules can activate and expand T cells for transfer, while improving their potency...