Aging is associated with dysfunction of the immune system at various levels. In the Proceedings of the National Academy of Sciences, Strominger and colleagues demonstrate that aging also impairs the ability of DCs to prime NK cells. DCs obtained from aged mice and stimulated with the RNA duplex poly(I:C) are ineffective at activating NK cells or priming their ability to respond to tumors. This dysfunction seems to be DC intrinsic because NK cells from aged mice are essentially normal in their responsiveness when primed by DCs from young mice. The impaired function of DCs from aged mice is a consequence of their lower expression of factors required for the priming of NK cells, such as the cytokines IL-15 and IL-18 or the plasma membrane molecule CD48. These data offer mechanistic insights into the age-related enhanced susceptibility to viruses and cancer.

PNAS (15 September 2014) 10.1073/pnas.1414780111