Establishment of an experimental model of autoimmune epididymo-orchitis induced by the transfer of a T-cell line in mice.

A murine T-cell line derived from BALB/c mice (designated B.T.1) was established which was capable of adoptively transferring experimental autoimmune orchitis (EAO) in normal recipients. The protocol consisted of preparing lymphocytes obtained from the mice that were immunized with syngenetic testicular germ cells (TGC) and the subsequent repeated selection of the lymphocytes in vitro by stimulation with murine testicular antigens (mTA). Phenotypic analysis revealed that B.T.1 cells were CD4+ T-cells. Intra-peritoneal inoculation of as few as 1 x 10(5) B.T.1 cells, that were stimulated in vitro with mTA before the inoculation, was capable of transferring EAO to naive recipients. In the latter, both delayed type hypersensitivity (DTH) and humoral responses to TGC were augmented. The transferred lesion was characterized by infiltration of inflammatory cells into the epididymis and rete testis and widespread aspermatogenesis in the testis. The transfer of EAO was unsuccessful when the recipients received B.T.1 cells that were maintained in culture medium without stimulation with mTA. In these recipients, anti-TC DTH was not detected, although the specific humoral response was observed. In-vitro characterization of the biological activity of B.T.1 cells revealed that the line had no cytolytic activity against TGC but the culture supernatant had macrophage migration inhibitory activity involved in the DTH response. Therefore, the DTH responsiveness transferred by B.T.1 cells was found to correlate with their orchitis-inducing capacity.