>Contents>Ocular Immune Privilege
Even before the modern concept of immunity had formed, scientists had discovered that certain tumors would grow progressively when transplanted into the anterior chamber of the eye, but not when transplanted elsewhere. With Medawar's discovery of the principles of transplantation immunology in the 1940s, it became possible to explain the biologic reasons for the surprising growth of tumors in the anterior chamber. Medawar demonstrated that foreign tissue grafts expressed transplantation antigens that were recognized by the recipient's immune system. In mounting a response against these antigens, immunity caused graft rejection. Medawar further demonstrated that this rule of transplantation immunology, which applied to most organs of the body, was relaxed in the eye. He found that foreign tissue grafts placed in the anterior chamber of the eye (as well as in the brain) often displayed prolonged survival without evidence of rejection, and coined the term 'immune privilege' to refer to this special property of the anterior chamber (and the brain).
By now, many other investigators have performed similar experiments by placing foreign tissue grafts at numerous special sites in the body. There is a long, but probably still incomplete, list of immune-privileged sites: anterior chamber, vitreous cavity and subretinal space of the eye, brain, pregnant uterus, ovary, testis, adrenal cortex and certain tumors. As researchers have probed the mechanisms responsible for immune privilege, it has become clear that similar, but not identical, processes are involved in conferring immune privilege on these various body sites.
The Eye's Dilemma
Immune Privilege
Anterior Chamber of the Eye as an Immune- Privileged Site
Inflammation of Relation to Innate and Adaptive Immune Responses
Ocular Factors That Promote Immune Tolerance of Eye-Derived Antigens
Factors That Modify Expression of Ocular Adaptive Immunity
Innate Immune Privilege in the Eye
Factors That Modify Expression of Innate Ocular Immunity
Clinical Meaning of Ocular Immune Privilege
Selected Reading
Biography
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