Functional characterization of the primate sperm acrosomal antigen (PSA-63).
Monoclonal antibody (HS-63) raised in mice against human ejaculated sperm, polyclonal antibodies raised in rabbits against the cognate mouse testicular antigen (MSA-63; or Fab) and polyclonal antibodies raised in the rabbit against recombinant fusion proteins (GST-63) showed acrosomal localization in permeabilized rhesus monkey and human ejaculated sperm. Tail localization of the cognate primate sperm antigen (PSA-63) was also seen with intact MSA-63 antibodies and Fab fragments. The ability of these antibodies to inhibit sperm binding to the zona pellucida was measured with hemizona binding assays (HZAs). HS-63 (1.2 mg/ml) inhibited rhesus monkey sperm binding (mean +/- SEM) to homologous hemizonae (treatment, 15.5 +/- 3.3; control, 58.9 +/- 9.4; P < 0.025), whereas comparable concentrations of protein from nonimmunized mouse preparations were inactive (ascites fluid, 67.6 +/- 43.5; no ascites fluid, 72.0 +/- 44.6). Intact MSA-63 antibodies inhibited (up to 99%) monkey sperm-zona binding in a concentration-dependent manner. Moreover, inhibition in this case by intact MSA-63 antibody was limited to capacitated sperm. Similarly, intact MSA-63 antibodies inhibited (up to 85%) human sperm binding to homologous zonae in an antibody concentration-dependent manner. Fab fragments derived from MSA-63, when present in insemination mixtures (0.5 mg/ml), inhibited (P < 0.01) primate sperm binding to homologous hemizonae (monkey, 9.6 +/- 3; human sperm 9.4 +/- 2) compared with matched hemizona controls (monkey, 117 +/- 29; human, 20.4 +/- 3). Furthermore, rhesus monkey sperm-zona binding was reduced by 84% in the presence of rabbit anti-GST-63 antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)
Archibong
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AE
Division of Reproductive Sciences, Oregon Regional Primate Research Center, Beaverton 97006, USA.
Lee
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CY
Wolf
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DP
D000177:Acrosome / Q000276:immunology*; D000818:Animals; D000918:Antibody Specificity; D000941:Antigens / Q000032:analysis*; D003269:Contraception, Immunologic / Q000379:methods*; D005260:Female; D006801:Humans; D008253:Macaca mulatta / Q000276:immunology*; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D011506:Proteins / Q000032:analysis*; D011817:Rabbits; D013045:Species Specificity; D013073:Sperm Agglutination; D013075:Sperm Capacitation; D013084:Sperm-Ovum Interactions / Q000276:immunology*; D015044:Zona Pellucida / Q000276:immunology
C512729:ACRV1 protein, human; C080034:Acrv1 protein, mouse; D000941:Antigens; D008565:Membrane Proteins; D011506:Proteins