Identification of epididymis-specific antigens using neonatal tolerization. 
Conventional immunization using whole sperm containing multiple antigens as the immunogen followed by hybridoma technology usually gives antibodies to antigens invariably of testicular origin, probably because of the strong immunogenic nature of these antigens.  Therefore, an alternate approach of neonatal tolerization or subtractive immunization has been utilized to raise antibodies specific to epididymis by suppressing immune response to testicular antigens.  Neonatal mice were tolerized with testicular sperm proteins on days 0 and 5.  These animals were then immunized with epididymal sperm proteins on day 21, followed by two boosters at biweekly intervals.  Sera from these mice were used to localize epididymis-specific antigens.  Sera from mice that were tolerized to testicular sperm proteins and later immunized with epididymal sperm proteins reacted only with epididymal proteins.  The results of this study demonstrate that neonatal tolerization with testicular sperm proteins, followed by immunization with epididymal sperm proteins, enhances the production of antibodies to proteins exclusively of epididymal origin.