NK cells can interact with keratinocytes through a range of cell surface receptors. NK cells express cell surface receptors that regulate their interactions with other cell types including keratinocytes. Among these receptors is the NKG2A/CD94 inhibitory receptor that recognises and binds to HLA-E on target cells. NK cells also express a number of activating receptors including NKG2D which recognises MICA/B stress antigen and the Fas receptor which can activate cytokine secretion by NK cells. The activating KIR receptor 2DS1 (and its inhibitory counterpart, 2DL1) binds the HLA-Cw6 molecule and HLA-Cw6 is the strongest genetic association known in psoriasis. There is evidence in the literature to suggest that these receptors play a role in psoriasis. Activated NK cells are triggered to release their cytotoxic granule contents which contain perforin and granzymes.
