Investigation In Vitro Expression of CatSper Sub Fragment followed by Production of Polyclonal Antibody: Potential Candidate for The Next Generation of Non Hormonal Contraceptive

CatSper is a voltage-sensitive calcium channel that is specifically expressed in the testis and it has a significant role in sperm performance. CatSper (1-4) ion channel subunit genes, causes sperm cell hyperactivation and male fertility. In this study, we have explored targeting of the extracellular loop as an approach for the generation of antibodies with the potential ability to block the ion channel and applicable method to the next generation of non-hormonal contraceptive. In this experimental study, a small extracellular fragment of CatSper1 channel was cloned in pET-32a and pEGFP-N1 plasmids. Then, subsequent methods were performed to evaluate production of antibody: 1) pEGFP-N1/CatSper was used as a DNA vaccine to immunize Balb/c mice, 2) The purified protein of pET-32a/CatSper was used as an antigen in an enzyme-linked immunosorbent assay (ELISA) and western- blot, and 3) The serum of Balb/-c mice was used as an antibody in ELISA and western-blot. The statistical analysis was performed using the Mann Whitney test. The results showed that vaccination of the experimental group with DNA vaccine caused to produce antibody with (p< 0.05) unlike the control group. This antibody extracted from Balb/c serum could recognize the antigen, and it may be used potentially as a male contraception to prevent sperm motility. CatSpers are the promising targets to develop male contraceptive because they are designed highly specific for sperm; although, no antagonists of these channels have been reported in the literature to date. As results showed, this antibody can be used in male for blocking CatSper channel and it has the potential ability to use as a contraceptive.