No lymphocyte infiltration was observed in any of the control mice testes (Fig. 1a–c). Conversely, extensive lymphocytic infiltration with spermatogenic disturbances was observed in all TGC-immunized EAO mice testes (Fig. 1e–g). Numerous lymphocytes surrounded the peripheral seminiferous tubules, resulting in aspermatogenesis (Fig. 1e–g). No. inflammation was observed in the epididymis of the TGC-immunized EAO mice (data not shown). Immunohistochemical analysis revealed that a portion of the lymphocytes in the interstitium and in the seminiferous tubules were B220-positive cells (Fig. 1g). Moreover, deposits of immunoglobulin (Ig) G were detected a portion of the lymphocytes that accumulated in the interstitium (Fig. 1h). No deposits of IgG and B220 were detected in any of the negative controls (Fig. 1c,d).