Developmental ontogeny of autoantigens associated with localized autoimmunity in murine testis and epididymis

Experimental autoimmune orchitis (EAO) with experimental autoimmune epididymitis (EAE) can be induced in mice by immunization with testicular antigens emulsified in adjuvants. On immunization with syngeneic testicular germ cells (TGC) alone, EAO with no EAE is induced in mice. Recently, we found that EAE with no EAO can be induced in vasectomized mice by immunization with TGC. In the present study, we investigated the appearance of autoantigens relevant to EAO and EAE by reacting each immune serum sample with testes and epididymides extracts from normal mice of various ages by immunoblotting. The results showed that the antisera obtained from mice with EAO lesions specifically defined testicular antigens with molecular weights of 15 kDa, 40 kDa, 75 kDa and >200 kDa from 4 weeks of age, but the antisera obtained from mice with EAE strongly defined both testicular and epididymal antigens of 25 kDa from 5 and 8 weeks of ages, respectively. These results suggest that vasectomy changes the target autoantigens in TGC-induced autoimmunity.