Intra-epithelial lymphocytes in the normal epididymis. A mechanism for tolerance to sperm auto-antigens?

Using a monoclonal immunoperoxidase technique on frozen tissue sections of normal testis and epididymis, a distinctive distribution of lymphocytes has been identified. Almost all of the intra-epithelial lymphocytes were T cells and the majority of these belonged to the T8+ ("suppressor/cytotoxic") subset. The distribution contrasted with the predominance of the T4+ ("helper/inducer") subset in the interstitial tissues and in normal peripheral blood. The predominance of the "suppressor/cytotoxic" subset within the epithelium of the epididymis may exist in order to prevent the development of the immune response to auto-antigens on spermatozoa.