• Monoclonal antibodies;
  • HLA;
  • DR;
  • human;
  • monkey;
  • buffalo;
  • rat;
  • mouse

ABSTRACT: There are conflicting reports about the presence of HLA and DR antigens on human sperm. The difference may be due to the complexity of anti-sera used by earlier researchers. These limitations have been overcome by using monoclonal antibodies in the present studies. The microcytotoxicity test was used to determine the presence of HLA and DR antigens on sperm of different species. It was observed that about 60% of human spermatozoa express HLA antigens and a slightly lower percentage (48%) express DR antigens. These antigens are highly cross-reactive with that of monkey and, to a lesser extent, with that of buffalo. Histocompatibility antigens expressed on epididymal spermatozoa of rat and mouse are also weakly reactive with monoclonal antibodies directed to human HLA and DR.