The role of chemokines and their receptors in ocular disease.

The migration and infiltration of cells into the eye whether blood-borne leucocytes, endothelial or epithelial cells occurs in many ocular diseases. Dysregulation of this process is apparent in chronic inflammation, corneal graft rejection, allergic eye disease and other sight-threatening conditions. Under normal and inflammatory conditions, chemokines and their receptors are important contributors to cell migration. To date, 47 chemokines and 19 chemokine receptors have been identified and characterised. In recent years, investigations into the role of chemokines and their receptors in ocular disease have generated an increasing number of publications. In the eye, the best understood action of these molecules has arisen from the study of their ability to control the infiltration of leucocytes in uveitis. However, the involvement of chemokines in angiogenesis in several ocular conditions and in the survival of corneal transplants demonstrates the multifaceted nature of their effects. Interestingly, the constitutive expression of chemokines and their receptors in ocular tissues suggests that certain chemokines have a homeostatic function. In this review, we discuss the nature and function of chemokines in health and disease, and describe the role of chemokines in the pathogenesis of different ocular conditions.