Epithelial-immune cell interaction in dry eye.

Dry eye is a potent stimulus of both innate and adaptive immune systems. At the nexus of the dry eye inflammatory/immune response is the dynamic interplay between the ocular surface epithelia and the bone marrow-derived immune cells. On the one hand, ocular surface epithelial cells play a key initiating role in this inflammatory reaction. On the other hand, they are targets of cytokines produced by activated T cells that are recruited to the ocular surface in response to dry eye. This interaction between epithelial and immune cells in dry eye will be thoroughly reviewed.