Identification and characterization of human acrosomal antigen defined by a monoclonal antibody with blocking effect on in vitro fertilization.
A monoclonal anti-human sperm antibody (Mab 1A1) has been produced by fusion of myeloma cells with splenocytes from a BALB/c mouse immunized with in vitro capacitated human spermatozoa. Immunofluorescence studies with Mab 1A1 show that it recognizes an antigen(s) (Ag 1A1) which is located in the acrosome of human spermatozoa. As shown by Western blotting experiments, 1A1 antigen represents a family of proteins with Mr ranging from 20 kDa to 34 kDa. Immunofluorescence observations on epitope exposure and location suggest that during in vitro capacitation of human spermatozoa, Mab 1A1 epitope-bearing molecules are concentrated in regularly arranged granules in the acrosome. After long-term incubation the epitope is exposed on the apical acrosome surface exhibiting a spot-like arrangement. The 1A1 epitope is widely distributed among mammalian species: boar, ram, mouse and rat acrosome is intensively stained by Mab 1A1. The antibody inhibits in vitro fertilization mainly by blocking sperm attachment to and penetration through the zona pellucida when included in the medium for the in vitro fertilization of mouse, porcine and human oocytes.
Dubova-Mihailova
M
M
Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, Sofia.
Mollova
M
M
Ivanova
M
M
Kehayov
I
I
Kyurkchiev
S
S
D000177:Acrosome / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000494:pharmacology; D000941:Antigens / Q000276:immunology / Q000302:isolation & purification*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013084:Sperm-Ovum Interactions; D013552:Swine; D015044:Zona Pellucida
D000911:Antibodies, Monoclonal; D000941:Antigens