Production of monoclonal antibodies to porcine zona pellucida and their inhibition of sperm penetration through human zona pellucida in vitro.

Two hybridoma cell lines producing murine monoclonal antibodies to antigens common to the zona pellucida (ZP) of pigs and humans were obtained by immunization of mice with solubilized porcine zona antigen. Indirect immunofluorescence tests showed that both these monoclonal antibodies stained the entire layer of porcine ZP but stained different regions of human ZP, one staining the entire layer and the other only the outer surface. At high concentrations, these two monoclonal antibodies directed against antigens common to porcine and human ZP prevented sperm binding and penetration into human ZP in vitro, whereas a monoclonal antibody directed against an antigen restricted to porcine ZP did not have these inhibitory effects. It is concluded that human and porcine ZP share at least two antigens with different locations in the ZP, and that these influence or are essential for interaction of human sperm with the ZP. These results provide a rationale for using porcine ZP clinically as a vaccine for human immunocontraception.