Inhibition of murine sperm-oolemma binding by antibodies to an oocyte membrane (OM) antigen: Implication in contraceptive vaccine development

Citation
Rk. Naz et al., Inhibition of murine sperm-oolemma binding by antibodies to an oocyte membrane (OM) antigen: Implication in contraceptive vaccine development, AM J REPROD, 45(1), 2001, pp. 52-61
Citations number
38
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Immunology
Journal title
AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY
ISSN journal
1046-7408 → ACNP
Volume
45
Issue
1
Year of publication
2001
Pages
52 - 61
Database
ISI
SICI code
1046-7408(200101)45:1<52:IOMSBB>2.0.ZU;2-L
Abstract
PROBLEM: The present study was conducted to investigate the oocyte membrane protein(s) that is involved in sperm binding in the mouse, and whether or not it can be used for the development of a contraceptive vaccine. METHOD OF STUDY: The zona-free oocytes were treated with Triton X-100 and t he extract was analyzed for homogeneity in the sodium dodecylsulfate (SDS)- polyacrylamide gel electrophoresis (PAGE) after staining with silver nitrat e. The appropriate band of 50 +/- 4 kD, designated as OM antigen, was excis ed from the gel and used for the immunization. The female rabbits were immu nized with the excised band per se and the female mice were immunized with the OM antigen after conjugation to keyhole limpet hemocyanin (KLH). The af finity-purified antibodies were analyzed in the enzyme-linked immunosorbent assay (ELISA), immunoprecipitation procedure, western blot procedure, indi rect immunofluorescence technique (IFT), and sperm-oolemma binding assay. A ctively-immunized mice were analyzed for in vivo fertility. RESULTS: The Triton X-100 extract of zona-free oocytes predominantly showed a single protein band of 50 +/- 4 kD in the SDS-PAGE. Active immunization of female rabbits and of female mice with OM antigen raised high antibody t iters (ELISA titer >1:4096) that specifically recognized the OM antigen in the immunoprecipitation and Western blot procedures, and reacted with the o ocyte in the IFT. These antibodies demonstrated a significant (P < 0.05) up to a complete block of sperm-oolemma binding in the in vitro binding assay . Binding of both the acrosome-intact and acrosome-reacted sperm was inhibi ted. Mice actively immunized with OM antigen also showed a significant redu ction in vivo fertility as seen by the 9-day implants in uteri. Preliminary data indicate that the antibodies to OM antigen were tissue-specific and d id not react with the specific band in any tissue extract in the western bl ot procedure. CONCLUSIONS: These results indicate that the OM antigen is involved in sper m-oolemma binding and constitute an attractive molecule that needs further investigation for examining its utility in the contraceptive vaccine develo pment.