Experiments on the internal secretion of the sexual glands, especially on experimental hermaphroditism

Reproductive immune microenvironment

About 10 %-12 % of couples in the world suffer from infertility, and immunological factors are being paid more and more attention. Attempts to induce peripheral immune tolerance in pregnant women by injecting husband cells have been widely promoted, but ultimately proved unsuccessful. Over the past two decades, our understanding of how the immune system is involved in gametogenesis and embryonic development, especially in early pregnancy, has undergone a major shift, going from the periphery to the local area of reproductive tissue. However, a holistic overview of immune responses in reproductive organs and tissues is currently lacking. Here, we further highlight the importance of regional immunity research for understanding reproductive health by reviewing the research mileage of the testis, ovary, and uterine immune microenvironment. We propose the concept of "reproductive immune microenvironment (RIM)" by summarizing the common features and basic functions of the tissue microenvironment in which immune cells reside, including the interstitial space of the testis, the ovarian stroma and the endometrium. The establishment of the concept of RIM not only focuses on the comprehensive description of the immune response in reproductive tissues, but also provides a macroscopic perspective for a deeper understanding of the immune etiology of reproductive system-related diseases.

Therapeutic application of Sertoli cells for treatment of various diseases

Sertoli cells (SCs) are immune privileged cells found in the testis that function to immunologically protect maturing germ cells from immune destruction. This immune protection is due to the blood-testis-barrier, which prevents infiltration of cytotoxic immune cells and antibodies, and SC production of immunomodulatory factors, that favor a tolerogenic environment. The ability of SCs to create an immune privileged environment has led to the exploration of their potential use in the treatment of various diseases. SCs have been utilized to create a tolerogenic ectopic microenvironment, to protect co-grafted cells, and to deliver therapeutic proteins through gene therapy. To date, numerous studies have reported the potential use of SCs for the treatment of diabetes, neurodegenerative disorders, and restoration of spermatogenesis. Additionally, SCs have been investigated as a delivery vehicle for therapeutic products to treat other diseases like Laron syndrome, muscular dystrophy, and infections. This review will provide an overview of these therapeutic applications.

Testicular defense systems: immune privilege and innate immunity

The mammalian testis possesses a special immunological environment because of its properties of remarkable immune privilege and effective local innate immunity. Testicular immune privilege protects immunogenic germ cells from systemic immune attack, and local innate immunity is important in preventing testicular microbial infections. The breakdown of local testicular immune homeostasis may lead to orchitis, an etiological factor of male infertility. The mechanisms underlying testicular immune privilege have been investigated for a long time. Increasing evidence shows that both a local immunosuppressive milieu and systemic immune tolerance are involved in maintaining testicular immune privilege status. The mechanisms underlying testicular innate immunity are emerging based on the investigation of the pattern recognition receptor-mediated innate immune response in testicular cells. This review summarizes our current understanding of testicular defense mechanisms and identifies topics that merit further investigation.

The immune privilege of testis and gravid uterus: same difference?

The fetus in the gravid uterus and the developing spermatogenic cells in the adult testis both comprise special challenges for the host immune system. Protection of the neoantigens of the fetus and male germ cells from immune attack, defined as immune privilege, is fundamental for the propagation of species. Immune privilege is not simply the absence of leukocytes, but involves immune and non-immune cells acting synergistically together at multiple levels to create a unique tolerogenic environment. A number of the pathways are shared by the testis and gravid uterus. Amongst them steroid hormones, namely testosterone in the male and progesterone in the female, seem to function as key molecules that govern the local production of immunoregulatory factors which finally control the overall immune environment.

Testisimmune privilege - Assumptions versus facts

The testis has long enjoyed a reputation as an immunologically privileged site based on its ability to protect auto-antigenic germ cells and provide an optimal environment for the extended survival of transplanted allo- or xeno-grafts. Exploration of the role of anatomical, physiological, immunological and cellular components in testis immune privilege revealed that the tolerogenic environment of the testis is a result of the immunomodulatory factors expressed or secreted by testicular cells (mainly Sertoli cells, peritubular myoid cells, Leydig cells, and resident macrophages). The blood-testis barrier/Sertoli cell barrier, is also important to seclude advanced germ cells but its requirement in testis immune privilege needs further investigation. Testicular immune privilege is not permanent, as an effective immune response can be mounted against transplanted tissue, and bacterial/viral infections in the testis can be effectively eliminated. Overall, the cellular components control the fate of the immune response and can shift the response from immunodestructive to immunoprotective, resulting in immune privilege.

Folliculogenesis following syngeneic transplantation of young murine ovaries into the testes

Background and Aim:  To examine the effects of intratesticular transplantation on the growth and maturation of young murine ovaries. Methods:  Two-week-old ovaries from transgenic mice with enhanced green fluorescent protein expression were transplanted under the testicular capsule of 4-week-old non-transgenic mice. Results:  Two months after transplantation all successfully grafted ovaries had survived, based on the presence of bright green fluorescence. The grafts showed various stages of folliculogenesis, including expanded follicles. The neighboring seminiferous tubules had a normal structure and mature sperm in their lumens, indicating active spermatogenesis, and all the recipient males were fertile. There was no evidence of extensive cell migration from the grafted ovaries into the testis. Similar findings were obtained for the grafted ovaries 6 months after surgery, although cell death (as evidenced by yellowish or pale fluorescence) was more frequent. Conclusion:  Young murine ovaries can grow and mature autonomously for at least 6 months unaffected by the male hormonal environment. (Reprod Med Biol 2006; 5: 71-77).

Studies in intersexuality. I.—A peculiar type of developmental intersexuality in the male of the domesticated mammals

During the past ten years three types of intersexuality have been made the subject of detailed examination. Lillie’s work on the bovine free-martin deals with a vertebrate form; that of Bridges on the fruit-fly Drosophila melanogaster , and of Goldschmidt on the Gipsy moth Lymantria , with invertebrate forms. It is the purpose of this paper to deal with a certain type of intersexuality, occurring among the domesticated mammals, which has not yet been brought into line with the general body of researches into that condition. Abnormality of the reproductive system, taking the form of an intimate mixture of male and female structures of the accessory sexual apparatus, and associated with some degree of imperfection of the external organs of generation, is not uncommon in the domesticated animals, and many cases in the human subject have been recorded. The condition has been referred to as “pseudo-hermaphroditism” and as “tubular partial hermaphroditism,” and John Hunter, in his treatment of the bovine free-martin, mentions that he had met with the same sort of abnormality in the horse, sheep, pig and goat. In the course of the last two years the present writer has examined thirty-five cases in the different domesticated mammals, and many of these have been described in detail in the 'Veterinary Journal.’

The testis and tissue transplantation: historical aspects

Transplantation experiments involving the testis have been performed since the days of John Hunter, who transplanted a testis into the belly of a hen. The first person to use the testis as a site of transplantation appears to have been Sand, who found in 1919 that an ovary transplanted into the substance of the testis developed follicles. By 1970, there was considerable evidence that the testis under some circumstances was a relatively favorable site for graft survival. However, much of the evidence was equivocal, and the immunological privilege was by no means complete.

Scrotal allografts of fetal ovaries

Fifty allografts of 17 day rat fetal ovaries were placed in the bottom of the scrotal wall of 25 normal and 25 castrated adult male rats. Of these, 5 did not take and 11 were destroyed by the allograft reaction. The remaining 34, which were reasonably tolerated, showed, whether the hosts were castrated or not, suppression of the cortical part of the ovary and stimulation of the medullary part, as evidenced by development of well-organized seminiferous tubules. This is presumably a reaction to the relatively cool environment of the scrotal wall.