Investigation of recombinant mouse sperm protein izumo as a potential immunocontraceptive antigen.
OBJECTIVE
To determine if the recombinant mouse Izumo (mIzumo) could be used as a potential immunocontraceptive antigen.


METHODS
The recombinant mIzumo fused with 6His tag (6His-mIzumo) was purified by immobilized Ni2+ affinity chromatography. Enzyme-linked immunosorbent assay and Western blot were used to detect anti-6His-mIzumo activities of serum from the mice immunized with 6His-mIzumo. Inhibition of the anti-6His-mIzumo antibody on mouse sperm-egg fusion in vitro was performed using the zona free oocytes and acrosome reacted sperm. Fertility of the 6His-mIzumo immunized male and female mice was compared with control mice.


RESULTS
The recombinant mIzumo was successfully produced. Female and male mice inoculated with 6His-mIzumo developed a specific serum antibody and the highest antibody titer lasted at least 6 weeks. The serum anti-6His-mIzumo antibody almost completely blocked mouse sperm-egg fusion in vitro. However, there was no significant reduction in fertility for both male and female mice immunized with 6His-mIzumo compared with control mice.


CONCLUSIONS
The circulated anti-mIzumo antibody can block mouse sperm-egg fusion in vitro but has no effect on fertility in vivo. It seems that application of Izumo as a candidate antigen in development of contraceptive vaccine needs further investigation.
Wang
De-Gang
DG
Research Center for Reproductive Medicine, Shantou University Medical College, Shantou, Guangdong, China.
Huang
Tian-Hua
TH
Xie
Qing-Dong
QD
An
Gang
G
D020101:Acrosome Reaction / Q000187:drug effects / Q000276:immunology; D000818:Animals; D003269:Contraception, Immunologic / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D005260:Female; D005298:Fertility / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007136:Immunoglobulins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D007274:Injections, Intraperitoneal; D008297:Male; D008565:Membrane Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D011247:Pregnancy; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D013094:Spermatozoa / Q000276:immunology / Q000378:metabolism*
D000939:Epitopes; D007074:Immunoglobulin G; D007136:Immunoglobulins; C498177:Izumo1 protein, mouse; D008565:Membrane Proteins; D011994:Recombinant Proteins