An antisperm monoclonal antibody inhibits sperm fusion with zona-free hamster eggs but not homologous eggs.
The zona-free hamster egg penetration assay (HEPA) was evaluated as a test for identifying fertilization-blocking antibodies. A monoclonal antibody, AH-20, that binds to the surface of guinea pig sperm was used to test antibody inhibition of sperm-egg fusion. AH-20 strongly inhibited guinea pig sperm fusion with zona-free hamster eggs but had no effect on guinea pig sperm fusion with zona-free guinea pig eggs. No inhibition by AH-20 was found in the homologous fusion assay over a wide range of sperm concentration, fertilization rate, and fertilization index. The results suggest that although guinea pig sperm can fuse with both hamster and guinea pig eggs, some aspect of the fusion mechanism is different in the two cases. The findings also indicate that HEPA, which is frequently used to assess the fertility potential of human sperm, can identify as blockers of sperm-egg fusion antibodies that have no effect on homologous sperm-egg fusion.
D000177:Acrosome / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001666:Binding Sites, Antibody; D006224:Cricetinae; D005260:Female; D005306:Fertilization; D005455:Fluorescent Antibody Technique; D006168:Guinea Pigs; D008297:Male; D015044:Zona Pellucida
D000911:Antibodies, Monoclonal