| Abstract: | The injection of lymph node cells or spleen cells, obtained from strain 13 guinea pigs rendered unresponsive to experimental allergic orchitis (EAO) by pretreatment with testicular antigen (TA) in incomplete Freund's adjuvant, into normal syngeneic recipients markedly prevented the development of EAO, especially of the interstitial inflammatory cell response, which was expected to occur 2 weeks following orchitogenic challenge with TA in complete Freund's adjuvant (CFA). The suppressive effect of thymus cells from the same donors was much less prominent. The inhibition of EAO by suppressor cells was specific for the relevant antigen TA. In such EAO-suppressed animals delayed skin reaction to TA was suppressed, whereas antisperm antibody formation was not impaired. The active suppressor cells residing in the lymph nodes had characteristics of T lymphocytes, in that they did not adhere to the plastic dish surface and nylon wool and in that they formed rosettes with rabbit erythrocytes. B lymphocytes from the same animals did not have detectable suppressive properties. Lymph node cells from protected donors that had been treated with a single dose of cyclophosphamide (CY) 3 days before cell transfer were unable to transfer unresponsiveness to EAO. The results suggest that the immune prevention against EAO is explainable at least in part by the generation of CY-sensitive suppressor T lymphocytes with the capacity of inhibiting development of effector T cells after antigenic stimulation and that suppressor cells that mediated unresponsiveness to EAO may also regulate the cellular hypersensitivity to TA. |
