Reversible Immunocontraception in Male Monkeys Immunized with Eppin

Abstract

Various forms of birth control have been developed for women; however, there are currently few options for men. The development of male contraceptives that are effective, safe, and reversible is desired for family planning throughout the world. We now report contraception of male nonhuman primates (Macaca radiata) immunized with Eppin, a testis/epididymis-specific protein. Seven out of nine males (78%) developed high titers to Eppin, and all of these high-titer monkeys were infertile. Five out of seven (71%) high-anti-Eppin titer males recovered fertility when immunization was stopped. This study demonstrates that effective and reversible male immunocontraception is an attainable goal. This method of immunocontraception may be extended to humans.

Identification, characterization, and evolution of a primate β-defensin gene cluster

“…Recently, our group reported fertility-related and antimicrobial roles of the androgenregulated sperm-binding protein, epididymal protease inhibitor (Eppin). 38,39 Similar roles for the defensins are currently under investigation.…”

Predicted seminal astacin-like protease is required for processing of reproductive proteins in Drosophila melanogaster

“…In addition to these reproductive modulators, the seminal fluid of many organisms contains proteases and protease inhibitors that regulate proteolytic events essential for reproduction: for example, in mammals, a protease inhibitor (protein C inhibitor, PCI) together with a protease (prostate-specific antigen, PSA) coordinates the degradation of semenogelins. This is thought to promote male fertility because it may enhance sperm motility by liquefying the seminal fluid (1)(2)(3)(4). Proteolysis regulators are also crucial for protein processing leading to semen coagulation and vaginal plug formation upon copulation (5) and are suggested to function in protecting sperm from premature acrosome reaction or from bacteria (6,7).…”

Milestones in contraceptive vaccines development and hurdles in their application

“…85 Immunization of male bonnet monkeys (Macaca radiata) with eppin led to the generation of high antibody titers with concomitant infertility in approximately 78% of the immunized animals. 86 Block in fertility was reversible as 5 out of 7 high-titerd monkeys regained fertility, subsequent to decline in the antibody titers. 86 …”

“…86 Block in fertility was reversible as 5 out of 7 high-titerd monkeys regained fertility, subsequent to decline in the antibody titers. 86 …”