Prospect for immunocontraception using the NH2-terminal recombinant peptide of human zona pellucida protein (hZPA).
OBJECTIVE
The zona pellucida is a feasible candidate for contraceptive vaccine. Our previous study showed that a human zona pellucida (ZPA) recombinant protein produced antiserum that inhibited human in vitro fertilization in rabbits. The objective of this study is to examine whether the human recombinant protein produce fertilization-blocking antiserum in a non-human primate.


METHODS
The amino terminal regions consisting of pig (198 amino acids) and human (206 amino acids) zona pellucida proteins were prepared by Escherichia coli to produce antisera in bonnet monkeys (Macaca radiata). Antibody production was assessed by immunofluorescent staining and enzyme-linked immunosorbent assay (ELISA). Fertilization-blocking test was carried out using human oocytes that had failed in intracytoplasmic sperm injection (ICSI) treatment under patient's informed consent.


RESULTS
Both antisera against pig and human recombinant proteins recognized native human zona pellucida by immunofluorescent staining. However, anti-recombinant human ZPA reacted to native pig zona protein more strongly than pig zona pellucida by ELISA. When human oocytes were treated with antisera before insemination, anti-human ZPA antiserum inhibited human sperm binding to human zona pellucida, but anti-pig ZPA antiserum did not.


CONCLUSIONS
Bonnet monkey produced fertilization-blocking antibody by immunization with human recombinant ZPA. The homologous or highly similar sequence is effective for developing a contraceptive vaccine when using recombinant peptides.
Koyama
Koji
K
Department of Obstetrics and Gynecology, Hyogo College of Medicine, Nishinomiya, Japan. kkoyama@hyo-med.ac.jp
Hasegawa
Akiko
A
Gupta
Satish K
SK
D000818:Animals; D000917:Antibody Formation; D003269:Contraception, Immunologic / Q000379:methods*; D004527:Egg Proteins / Q000737:chemistry / Q000276:immunology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008255:Macaca radiata; D008297:Male; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000276:immunology*; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology; D011817:Rabbits; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology; D013084:Sperm-Ovum Interactions / Q000276:immunology; D013552:Swine; D015044:Zona Pellucida / Q000276:immunology*; D000072216:Zona Pellucida Glycoproteins
D004527:Egg Proteins; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D000072216:Zona Pellucida Glycoproteins