Review of ocular immune privilege in the year 2010: modifying the immune privilege of the eye.

The original evidence for the existence of immunologically privileged sites in the body was based on the prolonged survival of genetically disparate transplanted tissue in the anterior chamber of the eye. The failure of the immune system to elicit an immune response in this and other such sites constitutes the hallmark of the immune privilege status. The remarkably successful field of corneal transplantation in clinical practice is undoubtedly associated with corneal immune privilege. Several investigations have addressed the regulatory mechanisms governing this phenomenon, which involves a complex interplay between multiple molecular and cellular pathways. Furthermore, the use of various transgenic mouse models has facilitated the identification of critical pathways, which upon disruption can modify the immune privileged status of the eye. Understanding these pathways not only reveals the mechanisms underlying various ocular inflammatory disease conditions, but also has clinical implications for the transplantation field and for the treatment of autoimmunity.