IL-15-dependent immune crosstalk between natural killer cells and dendritic cells in HIV-1 elite controllers

As the principal effector cell population of the innate immune system, natural killer (NK) cells may make crit-ical contributions to natural, immune-mediated control of HIV-1 replication. Using genome-wide assess-ments of activating and inhibitory chromatin features, we demonstrate here that cytotoxic NK (cNK) cells from elite controllers (ECs) display elevated activating histone modifications at the interleukin 2 (IL-2)/IL-15 receptor b chain and the BCL2 gene loci. These histone changes translate into increased responsiveness of cNK cells to paracrine IL-15 secretion, which coincides with higher levels of IL-15 transcription by myeloid dendritic cells in ECs. The distinct immune crosstalk between these innate immune cell populations results in improved IL-15-dependent cNK cell survival and cytotoxicity, paired with a metabolic profile biased toward IL-15-mediated glycolytic activities. Together, these results suggest that cNK cells from ECs display a pro-grammed IL-15 response signature and support the emerging role of innate immune pathways in natural,-free control of HIV-1.