Evaluation of recombinant fusion protein comprising dog zona pellucida glycoprotein-3 and Izumo and individual fragments as immunogens for contraception

Vaccine for human contraception targeting sperm Izumo protein and YLP12 dodecamer peptide

“…Subsequently, four studies have been published exploring Izumo1 as a contraceptive immunogen. Three of these studies confirmed our findings and reported a significant reduction in fertility of female mice after immunization with Izumo1 protein or cDNA . The fourth article concluded that immunization with Izumo1 does not cause a contraceptive effect in male and female mice.…”

“…(2) The authors used His 6 ‐tag recombinant Izumo1 protein for immunization. Recent studies have shown that the His 6 ‐tag can affect the efficacy of a vaccine . Antibodies against His 6 ‐tag recombinant Plasmodium falciparum MSP1 have lower percent parasite growth inhibition as compared with antibodies against tag‐free recombinant protein.…”

“…Antibodies against His 6 ‐tag recombinant Plasmodium falciparum MSP1 have lower percent parasite growth inhibition as compared with antibodies against tag‐free recombinant protein. His 6 ‐tag affects structural stability and immunodominance of a protein …”

“…Three of these studies confirmed our findings and reported a significant reduction in fertility of female mice after immunization with Izumo1 protein or cDNA. [33][34][35] The fourth article 36 concluded that immunization with Izumo1 does not cause a contraceptive effect in male and female mice. This study is flawed due to two reasons: (1) The authors used two groups of control mice for comparison with vaccinated male and female animals.…”

Ovarian function and pregnancy outcome in pony mares following immunocontraception with native and recombinant porcine zona pellucida vaccines

“…Similarly, porcine ZP4 (aa residues 22-462) was expressed in E. coli as a chimeric fusion protein incorporating a promiscuous T-cell epitope of bovine RNase (bRNase; aa residues 94-104; bRNase-KK-ZP4) [15]. Recombinant proteins were purified from inclusion bodies followed by refolding, as described previously [17]. Recombinant TT-KK-ZP3 and bRNase-KK-ZP4 were dialysed separately in 20 mmol/l Tris pH 6.0 and the respective protein concentration estimated using a BCA Protein Estimation Kit c and adjusted to 500 lg/ml.…”