Cytokines drive the formation of memory-like NK cell subsets via epigenetic rewiring and transcriptional mechanisms [ATAC-seq]

NK cells are innate lymphoid cells that protect the host against malignant and infected cells. Activation with the cytokines IL-12, IL-15, and IL-18 induces NK cells to differentiate into memory-like NK cells that have enhanced function compared to conventional NK (cNK) cells. However, mechanisms governing their biology and whether all cNK cells become memory-like are unclear. We identified that IL-12/15/18 activation results in two main fates: reprogramming into enriched memory-like (eML) or priming into effector (eff)cNK cells. eML NK cells have distinct epigenetics, phenotype, and enhanced function (IFNγ, cytotoxicity) compared to cNK and effcNK cells. In contrast, effcNK cells transcriptionally and epigenetically resemble cNK cells. Furthermore, we identify that within cNK cells CD56bright and CD56dim NK cells are the origin of distinct subsets of eML NK cells. Moreover, these two subsets of eML NK cells persist within patients receiving ML NK cell therapy for several months. Thus, IL-12/15/18 activation of NK cells results in multiple cell fates, with epigenetic and transcriptional mechanisms orchestrating eML NK cell differentiation and function. These mechanistic insights provide new strategies to enhance NK cellular therapy.