The natural killer cell: a further innate mediator of gouty inflammation?

Natural killer (NK) cells are vital effector cells of innate immunity because of their rapid cytotoxic and cytokine-producing responses to cell stress or infection. A distinguishing feature of NK cells is the ability to balance these signals with those of normal homeostasis through the expression of an array of inhibitory and activating receptors. Two functional subsets of NK cells exist: the more mature CD56(dim) population is potently cytotoxic, whereas CD56(bright) NK cells have low cytotoxicity but produce much greater amounts of cytokines, and express homing molecules for secondary lymphoid organs and sites of inflammation. NK cells have been identified as important modulatory cells in shaping adaptive immune responses by interacting with dendritic cells (DCs) and T cells. NK cells also interact with cells of the innate immune system such as monocytes and macrophages. This review outlines the biology of NK cells and the potential role of NK cells in modulating gouty inflammation.