Post-obstruction rat sperm autoantigens identified by two-dimensional gel electrophoresis and western blotting

Although antisperm autoantibody responses to obstruction of the male reprod uctive system have been documented, information on the nature of the cognat e sperm autoantigens has been limited. In the present study, the patterns o f sperm autoantigens recognized by sera from rats after obstruction of the vas deferens or epididymis were studied by high resolution two-dimensional (2-D) gel electrophoresis and western blotting. Comparisons of patterns of autoantigens stained on 2-D western blots of sera from prepubertal vasectom y, prepubertal epididymal ligation and adult vasectomy groups revealed both similarities and differences. Sera from sham-operated animals showed no de tectable reaction or much lighter staining of a small number of spots. Visu alization of sperm autoantigens on 2-D western blots supported the hypothes is that there is a relatively small set of sperm proteins that can be regar ded as dominant post-obstruction sperm autoantigens because they are recogn ized by. multiple post-obstruction sera. The 2-D analysis revealed previous ly undetected distinctions in the autoantigens recognized after adult and p repubertal vasectomy, as well as variations with the site of obstruction. T hese differences in the response may be due in part to changes in antigens of spermatozoa in different parts of the tract and at different ages, as we ll as variations in exposure of sperm cell proteins to the immune system re sulting from the sites of spermatic granulomas. Preparative: 2-D gels and w estern blotting with post-obstruction sera are now being used to identify s pecific sperm autoantigens by microsequencing of selected proteins. (C) 199 9 Elsevier Science Ireland Ltd. All rights reserved.