Studies on sperm antigenicity. 2. In vivo and in vitro cellular reactivity in guinea pigs sensitized to homologous and heterologous spermatozoal autoantigens.

In vitro delayed type hypersensitivity was demonstrated with peritoneal exudate cells from guinea pigs of the Rockefeller and Hartley strains, immunized with different preparations of the guinea pig male reproductive tract (RMT) emulsified in complete Freund's adjuvant-H37Ra. The RMT preparations were purified guinea pig spermatozoal autoantigens S, P, and T; whole guinea pig spermatozoa, and extract from epididymal tissue. The cellular sensitivity in vivo was demonstrated by injecting the proper antigen into the skin of the tested animals and in vitro by the macrophage inhibition technique. Peritoneal exudate cells from guinea pigs sensitized with whole guinea pig spermatozoa cells were inhibited in vitro by the specific antigen, epididymal extract, and autoantigen-T. Autoantigen-S was found to be a weak immunogen. However, the migration of peritoneal exudate cells from guinea pigs sensitized with large amounts of antigen-S was inhibited by whole spermatozoa in vitro. This cross-reactivity revealed the possibility that the immunogenicity of purified autoantigen-S might be connected to its molecular size. According to the immunizing dose of the antigens, testicular lesions of either the aspermatogenic or orchitis type were found in the testes of sensitized guinea pigs. Lesions in the testes of the guinea pigs were not detectable by cross-immunization with heterologous human or rat spermatozoa, although some degree of in vitro cross-reactivity was detected by skin test studies.