Identification of Arvicola terrestris scherman Sperm Antigens for Immune Contraceptive Purposes.

The cyclical proliferation of the wild fossorial rodent Arvicola terrestris scherman (ATS) is critical in mid-mountain ecosystems of several European countries. Our goal is to develop an immunocontraceptive vaccine to control their fertility, as a sustainable alternative to chemical poisons currently used. Indeed, these chemicals cause the death of ATS predators and animals sharing their ecosystem, and current laws progressively limit their use, making the development of a targeted vaccination strategy an interesting and efficient alternative. In order to identify species-specific sperm antigens, male and female ATS received subcutaneous injections of whole ATS spermatozoa to elicit an immune response. The analysis of the immune sera led to the identification of 120 immunogenic proteins of sperm cells. Of these, 15 were strictly sperm-specific and located in different regions of the male gamete. Some of these antigens are proteins involved in molecular events essential to the reproductive process, such as sperm-egg interaction, acrosomal reaction, or sperm motility. This approach not only identified a panel of immunogenic proteins from ATS sperm cells, but also demonstrated that some of these proteins trigger an immune response in both male and female ATS. These spermatic antigens are good candidates for the development of a contraceptive vaccine.

Comprehensive overview of murine epididymal mononuclear phagocytes and lymphocytes: Unexpected populations arise.

Despite increasing evidence that epididymal immune disorders can lead to infertility, the cells and mechanisms underlying epididymal immunity remain poorly understood. In this study, we propose a rather exhaustive overview of innate and adaptive immune cells present in the murine caput and cauda epididymis. Using flow cytometry and a wide set of markers, we screened the broadest panel of immune cells ever, in this organ. For the first time, we unequivocally quantified the innate populations of monocytes, macrophages, and dendritic cells subtypes. We also revealed the presence of B cells, gamma delta T cells, and double negative T cells in the murine epididymis. They were localized by immunofluorescence stainings, and appeared to be all present in the interstitium and epithelium along the organ, but with respective preferential regional distribution. Altogether, these findings provide new insights on the actors and potential mechanisms involved in the immune responses against genital tract ascending pathogens and in the setting and maintenance of tolerance toward the sperm cells.