Epigenetic regulation of natural killer cell memory*

Immunological memory is the underlying mechanism by which the immune system remembers previous encounters with pathogens to produce an enhanced secondary response upon re-encounter. It stands as the hallmark feature of the adaptive immune system and the cornerstone of vaccine development. Classic recall responses are executed by conventional T and B cells, which undergo somatic recombination and modify their receptor repertoire to ensure recognition of a vast number of antigens. However, recent evidence has challenged the dogma that memory responses are restricted to the adaptive immune system, which has prompted a reevaluation of what delineates immune memory. Natural killer (NK) cells of the innate immune system have been at the forefront of these pushed boundaries, and have proved to be more adaptable than previously thought. Like T cells, we now appreciate that their natural abilities actually require a myriad of signals for optimal responses. In this review, we discuss the many signals required for effector and memory NK cell responses and the epigenetic mechanisms that ultimately endow their enhanced features.

Automated summary

Immunological memory refers to the mechanism by which the immune system produces an enhanced secondary response upon re-encounter with pathogens. Recent evidence challenges the notion that memory responses are restricted to the adaptive immune system, with NK cells of the innate immune system also playing a crucial role. NK cells, like T cells, require multiple signals for optimal responses.