Local Na+ balance emerges as an important factor of tissue microenvironment. On the one hand, immune cells impact on local Na+ levels. On the other hand, Na+ availability is able to influence immune responses. In contrast to macrophages, our knowledge of dendritic cells (DCs) in this state of affair is rather limited. Current evidence suggests that the impact of increased Na+ on DCs is context dependent. Moreover, it is conceivable that DC immunobiology might also be influenced by Na+-rich-diet-induced changes of the gut microbiome.

Dendritic cells (DCs) represent important sentinel cells that continuously scan their microenvironment and play a key role in inducing immune responses and maintaining immunogenic tolerance [reviewed in (1–3)]. It is accepted that DCs are able to respond to a plethora of proteinaceous, lipid or carbohydrate molecules as well as nucleic acids via specialized receptors and signaling pathways [reviewed in (4–6)]. Recently, however, it emerged that the local Na+ electrolyte abundance impacts on innate and adaptive immune cell function and vice versa [reviewed in (7, 8)].