Vasectomy-induced autoimmunity: antisperm and antinuclear autoimmune monoclonal antibodies.

Antibodies to sperm and testicular autoantigens are a hallmark of vasectomy-induced murine autoimmunity. We generated five autoimmune monoclonal antibodies with spleen cells from nonimmunized but vasectomized BDF1 male mice as fusion partners in two experiments. Four of the antibodies, designated Vx 4, Vx 8, Vx 10, and Vx 23, recognize, as determined by fluorescence microscopy, topographically restricted sperm-specific antigenic determinants that appear in the germinal epithelium as spermatogenesis progresses. Antibodies Vx 8 and Vx 10 identified 60,000- and 97,000- dalton, mouse-specific sperm antigens restricted to the anterior acrosome and posterior acrosome, respectively. Antibody Vx 23 identified a 35,000- to 40,000- dalton antigen on the midpiece and postacrosomal regions of epididymal mouse sperm. The antigenic target of antibody Vx 4 on the midpiece region could not be identified with the Western blot technique. Both Vx 4 and Vx 23 cross-reacted with human, rabbit, and monkey sperm; immunofluorescence revealed that they were bound onto the midpiece region. By immunofluorescence, a single clone (Vx 24) distinctly reacted with the nuclei of somatic and testicular germ cells but not the nuclei of sperm. The isolation of this antinuclear autoantibody raises questions about the development of nonsperm-specific autoantibodies after vasectomy in the mouse.