Vaccination with an Epitope Peptide of IZUMO1 to Induce Contraception in Female Mice

Problem The development of a new and suitable contraceptive methods, as well as in-depth and systematic research into underlying contraceptive mechanisms, is crucial. IZUMO1 plays an important role in the fusion of the sperm and ovum during fertilization. Izumo−/− mice are infertile. Therefore, IZUMO1 may be a potential target for the development of a contraceptive vaccine. Method of study Linear B-cell epitopes (BCE) were identified in IZUMO using biosynthetic peptides and used to immunize female mice. Results Five IZUMO BCE were identified: DLVLDCL177-183, YSFYRV196-201 (named BCE-2), YLT217-219, SMVGPED221-227, and DAGNY228-232. Active immunization with the BCE-2 vaccine sharply decreased the fertility rate in female mice in a safe and reversible manner. In vitro fertilization showed that the BCE-2 vaccine interferes with and blocks the fusion of the sperm and the ovum. Conclusions B-cell epitopes-2 may be a new candidate for the development of contraceptive vaccine due to its effectiveness, safety, and reversibility.