Role of testicular autoantigens and influence of lymphokines in testicular autoimmune disease.

The present data on testicular autoimmune disease suggest that CD4+ helper type T cells are responsible for adoptive transfer of murine experimental autoimmune orchitis (EAO). In passive EAO, the earliest lymphoid cell infiltration is confined to terminal segments of seminiferous tubules. Both orchitis and vasitis develop. In active EAO, any location in the testis is affected, frequently involving subcapsular seminiferous tubules. The location of maximum histopathology in passive EAO coincides with the site in the normal testis that expresses maximal Ia. Demonstration of IgG in the testis after immunization with testicular antigens or after transfer of sera from orchiectomized mice immunized with testis shows that autoantigens are present on the germ cells outside the Sertoli cell barrier, suggesting the existence of dynamic protective mechanisms against immune responses to the non-sequestered autoimmunogenic germ cells in normal individuals.