Characteristics of immunotolerance induced by intratesticular injection of S-antigen

Experimental autoimmune uveoretinitis (EAU) induced by immunization of male Lewis rats with bovine S-antigen (S-Ag) is prevented by injection of S-Ag into the testis prior to immunization. This protection of animals is due to the induction of systemic immunotolerance or immunosuppression, which the authors designate orchidic tolerance. In this paper they first present a brief review of several features of orchidic tolerance reported previously and features uncovered more recently, and then propose a possible sequence of events that is initiated by antigen challenge in the testis and results in the proliferation of specific subclasses of lymphocytes with immunosuppressive activity and prevention of the onset of EAU.