Restoring NK cell cytotoxicity post-cryopreservation via synthetic IL-2-presenting cells

NK cell-based adoptive immunotherapy has gained increasing attention; however, cryopreservation, a standard technique for NK cell storage, significantly impairs NK cell cytotoxicity, particularly in physiological 3D environments. Here, we demonstrate that short-term co-culture with effector T cells markedly enhances NK cell motility and killing functionality.

Notably, a brief 1-day co-culture is sufficient to restore cryopreservation-impaired NK cell functionality in 3D environments. This enhancement requires direct contact between T cells and NK cells, which facilitates localized high concentrations of IL-2 at the cell contact sites. To develop a controlled, donor-independent solution, we demonstrate that synthetic T cells with surface-bound IL-2 or IL-15 exhibit superior efficiency in revitalizing cryopreserved NK cells.