How NKG2D Ligands Trigger Autoimmunity?

The function of NK and CD8 T cells in the elimination of infected, transformed, or stressed cells occurs together with tolerance to self, a property that is essential to prevent autoimmunity. Inappropriate expression of NK receptor ligands, leading to activation of autoreactive effector cells, might therefore trigger or exacerbate autoimmunity. We review here some recent data on the activating receptor NKG2D and its MIC ligand, which are indicative of their detrimental roles in some autoimmune disorders.