Post-vasectomy sperm autoimmunogens in the Lewis rat.

Vasectomy was performed on inbred Lewis rats to induce anti-sperm autoantibodies and to identify their cognate autoantigens. Different detergent extracts of cauda epididymal spermatozoa were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), blotted to nitrocellulose, and probed with sera from pre-vasectomy, post-vasectomy, and hyperimmunized animals to detect isologous sperm antigens. Nonreduced SDS-soluble autoantigens at greater than 200, 86, 43, and 26 kDa were bound by post-vasectomy antisera. Reduction of SDS-soluble antigens resulted in increased staining of the 86, 72-63, and 43 kDa autoantigens. Laemmli extraction of SDS insoluble pellets with beta-mercaptoethanol generated the largest repertoire of autoantigens including several autoantigens found in SDS-soluble extracts. Therefore, to analyze the entire repertoire of post-vasectomy autoantigens, whole sperm were extracted with Laemmli buffer under reducing conditions. Autoantiserum from most vasectomized animals bound Laemmli-extracted reduced autoantigens of approximately 86 (89-78), 63, 43, and 20 (21-16) kDa. Testicular extracts, reduced and separated by SDS-PAGE, contained autoantigens of 76, 60, and 42 kDa that were also recognized by hyperimmune and post-vasectomy antisera. The repertoire of sperm antigens recognized by pooled serum from hyperimmunized animals was similar to the cumulative repertoire recognized by post-vasectomy sera. These studies define several major sperm autoimmunogens recognized by post-vasectomy antisera and indicate that many of these peptide autoimmunogens are disulfide-bonded complexes.