Uropathogenic Escherichia coli Infection Compromises the Blood-Testis Barrier by Disturbing mTORC1-mTORC2 Balance

The structural and functional destruction of the blood-testis barrier (BTB) following uropathogenic E. coli (UPEC) infection may be a critical component of the pathologic progress of orchitis. Recent findings indicate that the mammalian target of the rapamycin (mTOR)-signaling pathway is implicated in the regulation of BTB assembly and restructuring. To explore the mechanisms underlying BTB damage induced by UPEC infection, we analyzed BTB integrity and the involvement of the mTOR-signaling pathway using in vivo and in vitro UPEC-infection models. We initially confirmed that soluble virulent factors secreted from UPEC trigger a stress response in Sertoli cells and disturb adjacent cell junctions via down-regulation of junctional proteins, including occludin, zonula occludens-1 (ZO-1), F-actin, connexin-43 (CX-43), β-catenin, and N-cadherin. The BTB was ultimately disrupted in UPEC-infected rat testes, and blood samples from UPEC-induced orchitis in these animals were positive for anti-sperm antibodies. Furthermore, we herein also demonstrated that mTOR complex 1 (mTORC1) over-activation and mTORC2 suppression contributed to the disturbance in the balance between BTB "opening" and "closing." More importantly, rapamycin (a specific mTORC1 inhibitor) significantly restored the expression of cell-junction proteins and exerted a protective effect on the BTB during UPEC infection. We further confirmed that short-term treatment with rapamycin did not aggravate spermatogenic degeneration in infected rats. Collectively, this study showed an association between abnormal activation of the mTOR-signaling pathway and BTB impairment during UPEC-induced orchitis, which may provide new insights into a potential treatment strategy for testicular infection.

Immuno-castration of female and male pigs with anti-gonadotrophin releasing hormone vaccine: Morphometric, histopathological and functional studies of the reproductive system

Immuno-castration is increasingly recommended in pigs due to welfare reasons; however, there are few studies in females compared to males. This aim of this study was to investigate the effects of immuno-castration in female and male pigs. The weight, the morphometric and microscopic characteristics of the reproductive organs, and the hormone concentrations were studied in 12 immunocastrated females (IF) and 12 immunocastrated males (IM) and compared with control animals (C). At slaughter, IF tended to have greater body weights than CF (P =  0.051), whereas in IM and CM pigs there were not body weight differences (P =  0.140). The weight of the reproductive tract and size of all individual organs were less in IF compared with CF. Results from histological assessments indicated IF had more atretic follicles and a thinner endometrial mucosa than control females. Hormone concentrations were not different between CF and IF (P >  0.050). As a result of immuno-castration, there was impaired spermatogenesis in most males. Results from microscopic evaluations indicated there was a marked decrease of spermatogonial cells and size of Leydig cells in the testicles. Accessory gland structures were affected in CM and IM with there being differences in gross and microscopic characteristics. Testosterone concentrations, unlike estradiol, were different in IM compared to CM (P <  0.001). These results provide evidence that immuno-castration with the anti-gonadotrophin releasing hormone vaccine is effective in female and male pigs and induces morphological and endocrine changes incompatible with fertility.

Bacterial infection of the male reproductive system causing infertility

Bacterial infections play a disruptive and hidden role in male reproductive failure. Different kinds of bacteria are often able to interfere with reproductive function in both sexes and lead to infertility. In this study, to further evaluate the role of bacterial infections in male reproduction we provided an extensive overview of so far researches investigating the effects of bacterial infections on male fertility. We searched Medline, PubMed, Scopus and Google scholar databases to identify the potentially relevant studies on bacterial infections and their implications in male infertility. All the bacteria included in this article have negative effects on the male reproductive function; however, there is ample evidence to blame bacteria such as Escherichia coli, Chlamydia trachomatis, Ureaplasma, Mycoplasma and Staphylococcus aureus for reduced fertility and deterioration of sperm parameters. More studies are needed to clarify the molecular mechanisms by which different bacteria exert their detrimental effects on male reproductive system. Getting more insight into probable mechanisms, would significantly facilitate the production of new, advanced, and effective remedies in the future. In view of all evidence, we strongly suggest increasing awareness among people and considering screening programs for patients seeking fertility both to avoid transmission and to improve fertility outcomes among them.

External and Genetic Conditions Determining Male Infertility

We explain environmental and genetic factors determining male genetic conditions and infertility and evaluate the significance of environmental stressors in shaping defensive responses, which is used in the diagnosis and treatment of male infertility. This is done through the impact of external and internal stressors and their instability on sperm parameters and their contribution to immunogenetic disorders and hazardous DNA mutations. As chemical compounds and physical factors play an important role in the induction of immunogenetic disorders and affect the activity of enzymatic and non-enzymatic responses, causing oxidative stress, and leading to apoptosis, they downgrade semen quality. These factors are closely connected with male reproductive potential since genetic polymorphisms and mutations in chromosomes 7, X, and Y critically impact on spermatogenesis. Microdeletions in the Azoospermic Factor AZF region directly cause defective sperm production. Among mutations in chromosome 7, impairments in the cystic fibrosis transmembrane conductance regulator CFTR gene are destructive for fertility in cystic fibrosis, when spermatic ducts undergo complete obstruction. This problem was not previously analyzed in such a form. Alongside karyotype abnormalities AZF microdeletions are the reason of spermatogenic failure. Amongst AZF genes, the deleted in azoospermia DAZ gene family is reported as most frequently deleted AZF. Screening of AZF microdeletions is useful in explaining idiopathic cases of male infertility as well as in genetic consulting prior to assisted reproduction. Based on the current state of research we answer the following questions: (1) How do environmental stressors lessen the quality of sperm and reduce male fertility; (2) which chemical elements induce oxidative stress and immunogenetic changes in the male reproductive system; (3) how do polymorphisms correlate with changes in reproductive potential and pro-antioxidative mechanisms as markers of pathophysiological disturbances of the male reproductive condition; (4) how do environmental stressors of immunogenetic disorders accompany male infertility and responses; and (5) what is the distribution and prevalence of environmental and genetic risk factors.

Repeated hormonal induction of spermiation affects the stress but not the immune response in pikeperch (Sander lucioperca)

Hormonal induction of spermiation, previously reported to be immunogenic in fishes, is a common hatchery practice in pikeperch, Sander lucioperca. The aim of the present study was to investigate the effects of repeated induction of spermiation in pikeperch, following application of either human chorionic gonadotropin (hCG) or salmon gonadoliberine analogue (sGnRHa) on sperm quality indices as well as on immune and stress response. Mature males of pikeperch (n = 7 per group) were stimulated twice with five days between injections of either hCG (hCG; 500 IU kg^-1), sGnRHa (sGnRHa; 50 μg kg^-1) or NaCl (control group; 1 ml kg^-1) to assess spermatozoa motility with a computer-assisted sperm analysis (CASA) system. During second sampling, blood plasma was sampled for humoral innate immune (peroxidase and lysozyme activities, ACH50), stress (cortisol, glucose) and endocrine (testosterone) markers. In addition, the head kidney was dissected to assay the expression of several immune genes (such as il1, c3, hamp, tnf-α and lys genes). The results indicate that hormonal treatment significantly increased sperm production. Sperm sampled after the hormonal treatment maintained its quality throughout the study, regardless of the sampling time. However, it appears that the application of hCG induced elevated cortisol and glucose plasma levels compared to the control group. Almost all immune markers, except the relative expression of hepcidin (hamp gene), were unaffected by the two hormones applied. The results showed that the induction treatment of spermiation processes in pikeperch resulted in an important physiological stress response for which the intensity varied according to the hormonal agent used. However, this stress response (more profound following application of hCG) was weakly associated with innate immune functions. On the other hand, a significant negative correlation between the expression of several important immune markers (peroxidase activity, relative expression of c3 and il1 genes) and sperm quality indices indicates significant involvement of immune status on sperm quality. The results obtained shed light on immune-system-induced modifications to sperm quality. The data presented here highlight the need for careful revision of broodstock management and selection practices where welfare status as well as individual predispositions of fish to cope with the stress should be taken under the consideration.

Unified single-cell analysis of testis gene regulation and pathology in five mouse strains

To fully exploit the potential of single-cell functional genomics in the study of development and disease, robust methods are needed to simplify the analysis of data across samples, time-points and individuals. Here we introduce a model-based factor analysis method, SDA, to analyze a novel 57,600 cell dataset from the testes of wild-type mice and mice with gonadal defects due to disruption of the genes Mlh3, Hormad1, Cul4a or Cnp. By jointly analyzing mutant and wild-type cells we decomposed our data into 46 components that identify novel meiotic gene-regulatory programs, mutant-specific pathological processes, and technical effects, and provide a framework for imputation. We identify, de novo, DNA sequence motifs associated with individual components that define temporally varying modes of gene expression control. Analysis of SDA components also led us to identify a rare population of macrophages within the seminiferous tubules of Mlh3-/- and Hormad1-/- mice, an area typically associated with immune privilege.

Egress of sperm autoantigen from seminiferous tubules maintains systemic tolerance

Autoimmune responses to meiotic germ cell antigens (MGCA) that are expressed on sperm and testis occur in human infertility and after vasectomy. Many MGCA are also expressed as cancer/testis antigens (CTA) in human cancers, but the tolerance status of MGCA has not been investigated. MGCA are considered to be uniformly immunogenic and nontolerogenic, and the prevailing view posits that MGCA are sequestered behind the Sertoli cell barrier in seminiferous tubules. Here, we have shown that only some murine MGCA are sequestered. Nonsequestered MCGA (NS-MGCA) egressed from normal tubules, as evidenced by their ability to interact with systemically injected antibodies and form localized immune complexes outside the Sertoli cell barrier. NS-MGCA derived from cell fragments that were discarded by spermatids during spermiation. They egressed as cargo in residual bodies and maintained Treg-dependent physiological tolerance. In contrast, sequestered MGCA (S-MGCA) were undetectable in residual bodies and were nontolerogenic. Unlike postvasectomy autoantibodies, which have been shown to mainly target S-MGCA, autoantibodies produced by normal mice with transient Treg depletion that developed autoimmune orchitis exclusively targeted NS-MGCA. We conclude that spermiation, a physiological checkpoint in spermatogenesis, determines the egress and tolerogenicity of MGCA. Our findings will affect target antigen selection in testis and sperm autoimmunity and the immune responses to CTA in male cancer patients.

NFLUENCE OF MAST CELLS ON REPARATIVE REGENERATION OF TISSUES WITH DIFFERENT DEGREE OF IMMUNOLOGICAL PRIVILEGES

It is assumed that tissues with different degree of imminological privileges have a number of distinctions in the processes of reparation. This may be associated with mast cells, which are found in all body tissues of an organism, secrete a wide range of biologically active substances and are important in the regulation of repair processes. This paper present the results of investigations of morphometric parameners and functional activity of mast cells in tissues with varying degrees of immune privilege (skin, testis). It has been shown that migration of must cells in the skin is observed early after the injury and followed by a slow increase of synthetic activity and index of degranulation of mastocytes within 30 days. Index of degranulation of mast cells in the testes increased immediately after the injury in the absence of their pronounced migration. Stabilizing membranes of mast cells using the drug ketotifen led to inhibition of the repair of the skin, which was manifested itself in the absence of increasing the thickness of dermis, epidermis, the number of fibroblasts and collagen fibers, and also in slowing down the formation of scar. At the same time, the inactivation of mast cells promoted reparative regeneration of testes as was indicated by increase in the number of normal spermatogonia which are proliferative pool for all subsequent stages of spermatogenesis, and by considerable decrease in the number of non-functioning tubules. Thus, the number and the functional sate of the mast cells have an impact on the course of reparative processes in tissues with varying degrees of immune privileges.

The effect of 17α-ethynylestradiol on steroidogenesis and gonadal cytokine gene expression is related to the reproductive stage in marine hermaphrodite fish

Pollutants have been reported to disrupt the endocrine system of marine animals, which may be exposed through contaminated seawater or through the food chain. Although 17α-ethynylestradiol (EE₂), a drug used in hormone therapies, is widely present in the aquatic environment, current knowledge on the sensitivity of marine fish to estrogenic pollutants is limited. We report the effect of the dietary intake of 5 µg EE₂/g food on different processes of testicular physiology, ranging from steroidogenesis to pathogen recognition, at both pre-spermatogenesis (pre-SG) and spermatogenesis (SG) reproductive stages, of gilthead seabream (Sparus aurata L.), a marine hermaphrodite teleost. A differential effect between pre-SG and SG specimens was detected in the sex steroid serum levels and in the expression profile of some steroidogenic-relevant molecules, vitellogenin, double sex- and mab3-related transcription factor 1 and some hormone receptors. Interestingly, EE₂ modified the expression pattern of some immune molecules involved in testicular physiology. These differences probably reflect a developmental adjustment of the sensitivity to EE₂ in the gilthead seabream gonad.

Effects of immunization against alpha-inhibin using two adjuvants on daily sperm production and hormone concentrations in ram lambs

Twenty-five ram lambs were immunized against alpha-inhibin peptide emulsified in Freund's adjuvant (FRA), Emulsigen (EML) containing an oligodeoxynucleotide as an immunostimulant, or adjuvant without alpha-inhibin antigen (control). Four immunizations were administered during an 85-d period, after which testes were obtained for determination of daily sperm production (DSP) and histological evaluation. alpha-Inhibin antibody (Ab) titers were 70-fold greater in lambs treated with FRA than in EML-treated ram lambs. alpha-Inhibin immunization had no effect on testes weight or on plasma concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone. Mean DSP/g tended (P=0.1) to be greater in alpha-inhibin-immunized (EML=17.6x10(6); FRA=15.8x10(6)) ram lambs than in control animals (14.4x10(6)). One of the 8 control ram lambs had an elevated DSP/g, which was a statistical outlier. Without data from this lamb, DSP/g was increased (P<0.01) in alpha-inhibin-immunized ram lambs by 28% over controls. No association was found between the titer of alpha-inhibin Ab developed and DSP/g. Histologically, the percentage of testicular area occupied by seminiferous tubules differed (P=0.01) by treatment and was greatest (82%) in EML-treated ram alpha-inhibin-immunized lambs and lowest (74%) in control animals. Percentage tubular area and DSP/g were correlated (r=0.57, P=0.003). Findings show that (1) the extent of the increase in DSP/g is not dependent on the titer of alpha-inhibin Ab; (2) the increase in DSP/g is achieved through an increase in the mass of seminiferous tubules; and (3) FRA elicits a greater alpha-inhibin Ab titer than EML containing an oligodeoxynucleotide.

Inflammatory networks in the control of spermatogenesis : chronic inflammation in an immunologically privileged tissue?

Spermatogenesis is a complex, organized process involving intimate interactions between the developing germ cells and supporting Sertoli cells. The process is also highly regulated. Studies suggest that regulation in the seminiferous epithelium involves molecules normally associated with either immune or inflammatory processes; in particular, interleukin 1a (IL1a), IL6, tumor necrosis factor (TNFa), activin A and nitric oxide (NO). While there is considerable evidence that these inflammatory mediators have effects on spermatogonial and spermatocyte development as well as critical supportive functions of the Sertoli cells, which are undoubtedly of considerable importance during testicular inflammation, there remains some skepticism regarding the significance of these molecules with respect to normal testicular function. Nonetheless, it is evident that expression of these regulators varies across the cycle of the seminiferous epithelium in a consistent manner, with major changes in production coinciding with key events within the cycle. This review summarizes the evidence supporting the hypothesis that inflammatory cytokines play a role in normal testicular spermatogenesis, as well as in the etiology of inflammation induced sub-fertility. The balance of data leads to the striking conclusion that the cycle of the seminiferous epithelium resembles a chronic inflammatory event. This appears to be a somewhat paradoxical assertion, since the testis is an immunologically privileged tissue based on its well-established ability to support grafts with minimal rejection responses. However, it may be argued that local immunoregulatory mechanisms, which confer protection from immunity on both transplanted tissues and the developing spermatogenic cells, are equally necessary to prevent local inflammation responses associated with the spermatogenic process from activating the adaptive immune response.

The presence of intra-tubular lymphocytes in normal testis of the mouse

Spermatoza contain various autoimmunogenic materials, which are recognized as foreign by the self immune system. Therefore, the blood-tesits-barrier (BTB) formed by Sertoli cells, basal lamina and myoid cells protects autoimmunogeneic spermatozoa from attack by the self immune system. However, the BTB at the tubuli recti (TR) and the rete testis (RT) is known to be incomplete against humoral substances. We investigated here whether the BTB is physiologically penetrated by lymphocytes in mice. We performed light and electron microscopical observation of the seminiferous tubules (ST), the TR and the RT in normal C3H/IHe mice. Although no lymphocytes were observed inside the ST, a very few lymphocytes could be found beyond the basal lamina of the TR and the RT. These lymphocytes were close to testicular spermatozoa in the TR lumen. These findings provide a possibility that lymphocytes may gain access to autoantigens of spermatozoa inside the TR and RT under physiological conditions in mice.

Expression of Aire and the early wave of apoptosis in spermatogenesis

Expression of the autoimmune regulator (Aire) protein in mice and humans is thought to be restricted to the medullary epithelial and monocyte-dendritic cells of the thymus. There it mediates expression and presentation of a large variety of proteins, including those that are peripheral organ-specific and are not expressed by other thymocytes. In this way, self-reactive T lymphocytes that would attack peripheral cells producing these proteins are confronted with the self-Ags and, as a consequence, are deleted. In this study, we show that Aire mRNA is also expressed in the testis--another tissue with promiscuous gene expression. Aire protein, however, is expressed only sporadically in spermatogonia and spermatocytes. Transcription of genes that are under Aire control in the thymus is unaffected by Aire in the testis. However, in mice with a disrupted Aire gene, the scheduled apoptotic wave of germ cells, which is necessary for normal mature spermatogenesis, is reduced, and sporadic apoptosis in adults is increased. Because Rag-1 deficiency does not abolish the effect, the adaptive immune system is not involved. We suggest that there is a link between the scheduled and sporadic apoptotic processes and propose that scheduled apoptosis provides a counterselection mechanism that keeps the germline stable.

Changes in spermatogenesis and endocrine function in the ram testis due to irradiation and active immunization against luteinizing hormone-releasing hormone

Spermatogonial stem cell transplantation is a technique that has potential in livestock to enhance genetic gain and generate transgenic offspring through the male germ line. A means for depletion of endogenous germ cells in a recipient's seminiferous tubules is necessary for this technology to be applied. The objectives of this study were to evaluate several methods for depletion of endogenous germ cells in the testes of adult rams and to evaluate ultrasound-guided injections into the rete testes as a means for infusing a suspension into the seminiferous tubules. Sixteen adult rams were randomly divided into 4 treatment groups (n = 4 per group). Treatments consisted of active immunization against LHRH (IMM), localized testicular irradiation (IR), LHRH immunization + irradiation (IMM+IR), and untreated control. Serial bleedings were conducted pretreatment and monthly after treatment for 4 mo, at which time all rams were castrated. Both IMM and IMM+IR rams received exogenous gonadotropin in the form of Perganol weekly for 8 wk before castration to bypass the immunization. All rams also received an ultrasound-guided injection of PBS containing 0.4% trypan blue into the rete testis of one testicle before castration. Rams receiving IMM and IMM+IR treatments had higher (P < 0.05) average percentages of seminiferous tubule cross sections with depleted germ cells compared with controls. Serum testosterone was decreased (P < 0.05) in IMM and IMM+IR rams 1 mo after treatment and throughout the remainder of the study compared with controls and IR rams, which were not different from each other. Serum inhibin concentration was unchanged in all rams following treatment indicating that Sertoli cell function was unaltered. A greater (P < 0.05) average percentage of the total testicular area could be filled with the trypan blue solution by rete testis injection in IMM and IMM+IR rams. These data demonstrate the depletion of endogenous germ cells in adult ram testes without alteration of Sertoli cell viability and function that have potential as methods for preparing recipient animals for germ cell transplantation.

Implication of Amphiphysin 1 and Dynamin 2 in Tubulobulbar Complex Formation and Spermatid Release

Tubulobulbar complexes (TBCs) are composed of several tubular invaginations formed at the plasma membrane of testicular Sertoli cells. TBCs are transiently formed at the contact region with spermatids at spermatogenic stage VII in rat and mouse, and such TBC formation is prerequisite for spermatid release. Since the characteristic structure of TBCs suggests that the molecules implicated in endocytosis could be involved in TBC formation, we here investigated the localization and physiological roles of endocytic proteins, amphiphysin 1 and dynamin 2, at TBCs. We demonstrated by immunofluorescence that the endocytic proteins were concentrated at TBCs, where they colocalized with cytoskeletal proteins, such as actin and vinculin. Immunoelectron microscopy disclosed that both amphiphysin 1 and dynamin 2 were localized on TBC membrane. Next, we histologically examined the testis from amphiphysin 1 deficient {Amph(-/-)} mice. Morphometric analysis revealed that the number of TBCs was significantly reduced in Amph(-/-). The ratio of stage VIII seminiferous tubules was increased, and the ratio of stage IX was conversely decreased in Amph(-/-). Moreover, unreleased spermatids in stage VIII seminiferous tubules were increased in Amph(-/-), indicating that spermatid release and the following transition from stage VIII to IX was prolonged in Amph(-/-) mice. These results suggest that amphiphysin 1 and dynamin 2 are involved in TBC formation and spermatid release at Sertoli cells.

Effects of estradiol infusion in GnRH immunized boars on spermatogenesis

Active immunization of boars against gonadotropin-releasing hormone (GnRH) inhibits luteinizing hormone (LH) and testicular steroids, so that mitosis of spermatogonia is reduced and apoptosis increased. To clarify whether high amounts of estrogens which are synthesized in the boar testis support spermatogenesis, a group of 6 boars was immunized against GnRH and then infused for 7 weeks with estradiol (E2-17beta). For comparison, intact boars and immunized boars were infused with saline only. Testicular tissue was then analyzed by immunocytochemistry for apoptosis (TUNEL, EM), mitosis (Ki67), and estrogen receptor alpha (ER alpha). The specificity of ER alpha staining was confirmed by RT-PCR and Western blot. Immunization decreased LH and testosterone to minimal concentrations in immunized and E(2)17beta-infused immunized boars, whereas follicle-stimulating hormone (FSH) was not significantly altered. Estradiol decreased to base levels after immunization. Infusion increased E2-17beta in peripheral blood plasma of the immunized boars to physiological levels. Except for A-spermatogonia, all spermatogenic cells decreased after immunization by about 60%. After estradiol infusion, cell counts increased again and were intermediate between control and immunized boars. Mitosis of spermatogonia was reduced by nearly 50% due to immunization but was partly restored by E2-17beta infusion. Expression of ER alpha was localized in spermatogonia, suggesting stimulation of mitosis, which was further confirmed due to its predominant occurrence in stage I of the seminiferous epithelial cycle (main stage of cell division). Apoptosis was minimal in boars but elevated in the other 2 groups. Data showed that estrogens in physiological concentrations supported mitosis but were not sufficient to normalize sperm production because apoptosis was still high.

Immune Complex Deposition in Adult Male Sprague-Dawley Rats Chronically Immunized with GnRH

PROBLEM

This study was undertaken to evaluate whether the anti-GnRH antibodies and immune complexes (IC) generated by immunization with GnRH-TT cause cellular damage within the animal.

METHOD OF STUDY

Chronic immunization of rats with GnRH-TT injected i.m. was followed by tissue/organ analysis for immune complex deposition by immunofluorescence microscopy. Two groups were studied: (1) those immunized throughout the experiment until their ultimate demise, and (2) those given a chance to recover from the effects of chronic immunization before final analysis.

RESULTS

GnRH-TT was effective in stopping spermatogenesis, which resumed after withdrawal of the immunogen. Most tissues from chronically immunized animals were not significantly different than controls, however the kidneys of treated animals exhibited a higher accumulation of IC. Despite increased IC deposition, pathologic effects were not detected at the cellular level.

CONCLUSIONS

GnRH-TT is an effective immunocontraceptive although the accumulation of glomerular IC represents a potential deleterious side effect.

A synthetic gonadotropin-releasing hormone (GnRH) vaccine for control of fertility and hormone dependent diseases without any adjuvant

Active immunization against self-peptides have gained widespread acceptance inspite of their low immunogenicity. Recent applications involving multiple copies of self-peptides in linear alignment and conjugation with carrier proteins appear to increase the immune response against self-peptides. As with most vaccines, however, immunogens require supplementation with adjuvants to elicit an optimum immune response. In the present study, we prepared a double-chain mini-protein with each chain containing three linear repeats of the self-peptide gonadotropin-releasing hormone (GnRH3), the hinge region of human IgG1 (hinge), and a T-helper epitope from the measles virus protein (MVP). The GnRH3-hinge-MVP mini-protein was conjugated to purified recombinant heat shock protein 65 (Hsp 65) of Mycobacterium bovis and used to immunize rats primed with subcutaneous injections of Bacillus Calmette-Guerin (BCG) in the absence of adjuvants. The GnRH3-hinge-MVP-Hsp 65 stimulated the production of specific anti-GnRH antibodies in the absence of adjuvants and the antibody titer was comparable to that produced in rats immunized with the dimeric mini-protein in the presence of Freund's adjuvant. Moreover, immunization with the adjuvant-free GnRH3-hinge-MVP-Hsp 65 induced degeneration of the reproductive organs in both male and female rats unlike those immunized in the absence of Hsp 65 or in control animals inoculated with the vehicle only. Histological examination of the affected organs showed atrophy of the seminiferous tubules with diminished spermatogenesis in the testes of male rats. In female rats, the uteri were much smaller in size and the ovaries exhibited reduced follicular development. These findings demonstrated that GnRH3-hinge-MVP-Hsp 65 mounted a strong immune response in the absence of conventional adjuvants, and could prove useful in control of fertility and the treatment of conditions/diseases where GnRH ablation is required.

Interleukin-18 is expressed in rat testis and may promote germ cell growth

Although host-defence mechanisms, designed to preserve the integrity of the developing germ cells are operative in the testis, the components of this protective system have yet to be characterised in detail. Here, we report that the cytokine interleukin-18 (IL-18) is expressed in the rat testis and may contribute to these defences. Thus, analysis by RT-PCR and Western blotting revealed pronounced testicular expression of pro-IL-18 from postnatal day 5 and onwards. Expression of both IL-18 mRNA and protein was found to be localised to meiotic and post-meiotic germ cells as evaluated by in situ hybridisation and immunohistochemistry, respectively. The mRNA species coding for the IL-18 receptor and IL-1beta converting enzyme, which activates pro-IL-18, were also shown to be expressed by the seminiferous tubules. Recombinant IL-18 was seen to stimulate spermatogonial DNA synthesis in cultures of staged segments of rat seminiferous tubules, without influencing germ cell apoptosis. These results suggest that IL-18 may have host-protective and growth-promoting functions in the testis, but further investigations need to be done to confirm this.

Tissue microcircumstances for leukocytic infiltration into the testis and epididymis in mice

Spermatozoa do not appear in the seminiferous epithelium until puberty, when immune tolerance has already been established. Therefore, they contain various autoimmunogenic materials which are recognized as foreign by the self immune system. However, the testis and epididymis are known as immunologically privileged organs. In particular, the blood-testis barrier (BTB) formed by Sertoli cells and the blood-epididymal barrier formed by epididymal epithelial cells protect autoimmunogeneic spermatozoa from attack by the self immune system. The immune privileged circumstances in the testis and epididymis have been demonstrated by many studies to involve a local transplantation system. We review here the immune privileged status of these organs from the viewpoint of induction of inflammatory cell responses in mice. The testicular interstitium in mice is resistant to vasculitis, lymphangitis, spermatic granuloma and polymorphonuclear cell infiltration: however, the epididymal interstitium is vulnerable to them. Therefore, the testicular tissue outside BTB is also protected from inflammatory cell infiltration, although many resident macrophages are normally present in the testis. In sharp contrast, subcutaneous injection of viable syngeneic testicular germ cells (TGC) alone induces autoimmune orchitis with no involvement of the epididymitis in mice. In the testes of TGC-immunized animals, severe lymphocytic infiltration with aspermatogenesis was seen in spite of no use of adjuvants. Unexpectedly, injections of viable epididymal spermatozoa (ES) did not evoke any autoimmune inflammation in the epididymides. Therefore, the testis rather than the epididymis may easily become an unprivileged organ as to autoimmunity under some special conditions.

Contraceptive vaccines

The world's population is growing at a tremendous rate, affecting growth and development. Apart from this population growth, unintended pregnancies resulting in elective abortions continue to be a major public health issue. In over half of these unintended pregnancies, the women have used some type of contraception. Thus, there is an urgent need for a better method of contraception that is acceptable, effective and available. The contraceptive choices available to women at this time include steroid contraceptives, intrauterine devices, barrier methods, spermicides, natural family planning, male and female sterilisation, and recently available emergency contraceptives. Contraceptive vaccines (CVs) may provide viable and valuable alternatives that can fulfill most, if not all, properties of an ideal contraceptive. Since both the developed and most of the developing nations have an infrastructure for mass immunisation, the development of vaccines for contraception is an exciting proposition. The molecules that are being explored for CV development either target gamete production (gonadotropin releasing hormone, follicle-stimulating hormone and luteinising hormone), gamete function (zona pellucida [ZP] proteins and sperm antigens) or gamete outcome (human chorionic gonadotropin [hCG]). Disadvantages of CVs targeting gamete production are that they affect sex steroids and/or show only a partial effect in reducing fertility. CVs targeting gamete function are better choices. Vaccines based on ZP proteins are quite efficacious in producing contraceptive effects. However, they invariably induce oophoritis affecting sex steroids. Sperm antigens constitute the most promising and exciting targets for CVs. Several sperm-specific antigens have been delineated in several laboratories and are being actively explored for CV development. Antisperm antibody-mediated immunoinfertility provides a naturally occurring model to indicate how an antisperm vaccine will work in humans. Vaccines targeting gamete outcome primarily focus on the hCG molecule. The hCG vaccine is the first vaccine to undergo phase I and II clinical trials in humans. Both the efficacy and the lack of immunotoxicity have been reasonably well demonstrated for this vaccine. The present studies focus on increasing the immunogenicity and efficacy of this birth control vaccine.

Reproductive and neurological Quaking(viable) phenotypes in a severe combined immune deficient mouse background

The quaking(viable) (qkv) mutation, a spontaneous deletion of a multigenic region encompassing roughly 1 Mb at 5.9 cM on the proximal end of mouse chromosome 17, causes severe trembling in all homozygous animals and infertility in all homozygous males. Physiologically, quaking mice exhibit dysmyelination and postmeiotic spermatogenic arrest. Molecular defects in Qkv mice occur in the affected tissues, indicating the primary causes of these pathologies are cell autonomous. However, because both the reproductive and neurological defects are in immune-privileged sites and because some similar pathologies at both sites have been shown to be immune mediated, we tested whether the immune system participates secondarily in manifestation of Qkv phenotypes. The qkv mutation was bred into a severe combined immune-deficient mouse line (SCID; devoid of mature B and T cells) and penetrance of the neurological and the male sterile phenotypes was measured. Results showed that neither defect was ameliorated in the immune-deficient background. We conclude that the Qkv pathologies do not likely involve a B- or T-cell-dependent response against these immune-privileged sites.

Phenotypic characterization of the immune and mast cell infiltrates in the human testis shows normal and abnormal spermatogenesis

OBJECTIVE

To assess the types, distributions, and numbers of immune cell infiltrates in the testes of men with azoospermia.

DESIGN

Prospective study.

SETTING

University research and clinical institutes.

PATIENT(S)

Thirty-one men with azoospermia showing normal spermatogenesis (n = 10), germ cell maturation arrest (GA, n = 12), and Sertoli cell-only syndrome (SCO, n = 9).

INTERVENTION(S)

Testicular tissue biopsies. Sections were stained with routine (hematoxyline and eosin), special (Masson Trichrome, Gordon, Periodic Acid Schiff, Aldehyde Fuchsin, and Orcein stains), and immunoperoxidase stains (using monoclonal antibodies for B and T cells and CD68 macrophages).

MAIN OUTCOME MEASURE(S)

Serum levels of T, FSH, and LH in addition to histopathological analysis.

RESULT(S)

Hormonal profiles were unremarkable in all patients. Marked deposition of the reticular and collagen fibers was seen more in abnormal than normal spermatogenesis. The immune (B and T lymphocytes and CD68 macrophages) and mast cells were found in the interstitium, tubular walls, and lumens of all the testes analyzed. The differential counts of these cells (B and T lymphocytes, CD68 macrophages, and mast cells, respectively) were higher in SCO (1.66 +/- 0.46, 9.14 +/- 1.30, 2.26 +/- 1.68, 3.35 +/- 0.23) and GA (2.03 +/- 0.48, 4.70 +/- 1.00, 2.61 +/- 0.70, and 4.18 +/- 0.13) when compared with those in normal spermatogenesis (1.22 +/- 0.19, 5.41 +/- 0.58, 1.55 +/- 0.33, and 2.26 +/- 0.13). Increased cellular counts were not statistically significant for T and B cells and macrophages. However, these differences were statistically significant for mast cells.

CONCLUSION(S)

Abnormal spermatogenesis is associated with increased numbers of the immune and mast cells. Our findings may reflect an exaggerated immune response in these cases.

Induction of castration by immunization of male dogs with recombinant gonadotropin-releasing hormone (GnRH)-canine distemper virus (CDV) T helper cell epitope p35

Immunocastration is a considerable alternative to a surgical castration method especially in male animal species for alleviating unwanted male behaviors and characteristics. Induction of high titer of antibody specific for gonadotropin-releasing hormone (GnRH) correlates with the regression of testes. Fusion proteins composed of canine GnRH and T helper (Th) cell epitope p35 originated from canine distemper virus (CDV) F protein and goat rotavirus VP6 protein were produced in E. coli. When these fusion proteins were injected to male dogs which were previously immunized with CDV vaccine, the fusion protein of GnRH-CDV Th cell epitope p35 induced much higher antibody than that of GnRH-rotavirus VP6 protein or GnRH alone. The degeneration of spermatogenesis was also verified in the male dogs immunized with the fusion protein of GnRH-CDV Th cell epitope p35. These results indicate that canine GnRH conjugated to CDV Th cell epitope p35 acted as a strong immunogen and the antibody to GnRH specifically neutralized GnRH in the testes. This study also implies a potential application of GnRH-based vaccines for immunocastration of male pets.

Monoclonal Antibodies against Sperm Intra-acrosomal Antigens as Markers for Male Infertility Diagnostics and Estimation of Spermatogenesis

PROBLEM

To determine the ability of monoclonal antibodies (MoAbs) against acrosomal antigens to detect physiology and pathology of human spermatozoa and to detect spermatids in ejaculates of infertile male with azoospermia.

METHOD OF STUDY

Sperm antigens detected with prepared MoAbs were partially characterized by biochemical and immunocytochemical methods. The acrosomal status of spermatozoa was compared in men with normal and pathological spermiograms and in sperm before and after induced acrosome reaction (AR). Ejaculates from patients were tested for the presence of spermatids.

RESULTS

MoAbs specifically bind to intra-acrosomal sperm antigens with quantitative difference between ejaculates with normal and pathological spermiograms. These antigens are released from the acrosome after induced AR. MoAbs labeled acrosomal proteins in round and elongated spermatids in the ejaculates of patients with azoospermia.

CONCLUSION

MoAbs against intra-acrosomal sperm antigens are useful for human sperm diagnosis and prediction of spermatogenesis. The spermatids can be utilized in assisted reproduction.

Fate vs Choice: The Immune System Reloaded

Development can occur by either instructive or stochastic processes. My colleagues and I have studied the contributions of these processes to differentiation of naïve CD4+ T-cells to either a Th1 or Th2 phenotype. Our initial discovery that pathogens in our in vitro priming system led to the development of Th1 cells through the action of interleukin-12 was important evidence of a link between innate and adaptive immunity. Subsequent studies in our laboratory revealed an important role for GATA-3 autoactivation in Th2 development. Other interesting projects that have emerged as a result of our Th cell differentiation studies include understanding the role of the inhibitory immunoreceptor B- and T-lymphocyte attenuator in the immune response, as well as the role of the transcription factor ERM in both T-cells and spermatogenesis. We currently maintain our interests in the Th differentiation field by trying to understand the role of type 1 interferons in Th1 development and the role of alternate promoters for the GATA-3 gene, among other things, but are also actively embarking on studies related to the choice between divergent cell types during embryonic stem cell differentiation.

Efficacy of an anti-fertility vaccine based on mammalian gonadotrophin releasing hormone (GnRH-I)—a histological comparison in male animals

A N-terminal modified gonadotrophin releasing hormone (GnRH-I, tetanus toxoid-CHWSYGLRPG-NH2) conjugate was evaluated histologically in a number of male animal species (mice, dogs and sheep). The immunogen has previously been shown to be highly effective in rats, by suppressing both steroidogenesis and spermatogenesis. However, cross-species efficacy of peptide vaccines is known to be highly variable. Therefore, a comparative evaluation of reproductive tissues from animals immunized against this immunogen adsorbed onto an alum-based adjuvant was made. The sheep and dogs were chosen, as use of anti-fertility vaccines in these species is important in farming and veterinary practice. Changes in testicular size were measured during the immunization period and the greatest alteration (attributed to gonadal atrophy) was observed in the rat. Following euthanasia, the testicular tissue was evaluated for spermatogenesis. The most susceptible species to GnRH-I ablation was the rat, which showed significant (P < 0.0001) arrest in spermatogenesis compared with untreated controls. Testicular sections taken from treated animals were completely devoid of spermatozoa or spermatids, in comparison with 94% of the untreated controls showing evidence of spermatogenesis. The immunized mice and rams also showed significant arrest (P < 0.0001). There was a 30-45% decrease in spermatogenesis and total azoospermia was not apparent. However, the least responsive were the dogs, which showed little significant variation compared to untreated animals and only a 5% decrease in activity. A comparison of the specific IgG response to GnRH-I indicated that in sheep and dogs the response was not maintained, unlike in rodents, suggesting that suppression of fertility may be due to differences in immune responses in different animal species.

Cytokines and the immune-testicular axis

Cytokines are regulatory proteins involved in haematopoiesis, immune cell development, inflammation and immune responses. Several cytokines have direct effects on testicular cell functions, and a number of these are produced within the testis even in the absence of inflammation or immune activation events. There is compelling evidence that cytokines, in fact, play an important regulatory role in the development and normal function of the testis. Pro-inflammatory cytokines including interleukin-1 and interleukin-6 have direct effects on spermatogenic cell differentiation and testicular steroidogenesis. Stem cell factor and leukaemia inhibitory factor, cytokines normally involved in haematopoiesis, also play a role in spermatogenesis. Anti-inflammatory cytokines of the transforming growth factor-beta family are implicated in testicular development. Consequently, local or systemic up-regulation of cytokine expression during injury, illness or infection may contribute to the disruption of testicular function and fertility that frequently accompanies these conditions. The aim of this review is to provide a very brief summary of the extensive literature dealing with cytokines in testicular biology, and to follow this with some speculation concerning the significance of these molecules in interactions between the immune system and the testis.

Identification, cloning, and initial characterization of a novel mouse testicular germ cell-specific antigen

A monoclonal antibody, designated TES101, was raised by immunizing BALB/c mice with an allogenic mouse testicular homogenate followed by immunohistochemical selection as the initial screening method. By searching the expressed sequence tag (EST) database with the N-terminal amino acid sequence of TES101 reactive protein, we found that the predicted amino acid sequence encoded by a mouse testicular EST clone matched the TES101 protein sequence. Sequence analysis of the clone revealed no homologous molecule in the DNA/protein database. Based on data obtained from N-terminal amino acid analysis of the TES101 protein, the derived amino acid sequence contained a signal peptide region of 25 amino acids and a mature protein region of 225 amino acids, which translated into a protein with a molecular weight of 24 093. Northern blot analysis showed that mRNA of the TES101 protein was found in testis but not in any other mouse tissues examined. Western blot analysis revealed that TES101 reacted with a 38-kDa band on SDS-PAGE under nonreducing conditions, and this reactivity was abrogated under reducing conditions. Immunoelectron microscopic studies demonstrated that the molecule was predominantly located on the plasma membrane of spermatocytes and spermatids but not in Sertoli cells or interstitial cells, including Leydig cells. Thus, the TES101 protein is a novel molecule present primarily on the surface of developing male germ cells. TES101 protein may play a role in the processes underlying male germ cell formation.

Immune responses in the epididymis: implications for immunocontraception

In recent years the need to develop vaccines against a variety of sexually transmitted diseases, the desire to treat male infertility and interest in developing alternative contraceptive methods have focused research interest on the immunology of the male reproductive tract. This paper reviews the current state of knowledge of immunity in the male tract. Both physical and immune mechanisms that operate to maintain the blood-testis barrier are discussed with regard to (i) their importance in preventing autoimmune responses against spermatozoa and (ii) how these can be overcome to induce specific immunity in the testis and efferent ducts. The role of both the systemic and mucosal arms of the humoral immune response are discussed both in terms of immune-mediated infertility and the induction of specific immunity. Finally some novel approaches to elicit immunity in the male reproductive tract are discussed.

Immunologic aspect of testicular torsion: detection of antisperm antibodies in contralateral testicle

OBJECTIVE

To evaluate the immunologic etiology in unilateral testicular torsion, an experimental study in rats was carried out.

MATERIALS AND METHODS

75 adult Wistar rats included in the study program were divided into six different groups according to a torsion-detorsion procedure. Torsion degree was kept constant for all animals (720 degrees ). Anti-rat immunoglobulin G (IgG) antibodies against spermatozoa antigens were identified in contralateral testicular tissue after 1 month following detorsion and/or orchiectomy of the twisted testicle.

RESULTS

We revealed antibody formation in animals subjected to unilateral torsion for 12 and 24 h, which then followed by detorsion of the testicle. IgG was identified especially on basal membrane of the tubules.

CONCLUSIONS

As the controversy on the exact mechanism of testicular damage in unilateral torsion still continues, our findings showed that a possible immunological etiology may play an important role in this respect.

A novel stage-specific antigen is expressed only in early stages of spermatogonia in Japanese eel, Anguilla japonica testis

We produced an antibody that recognized only early stages of spermatogonia in Japanese eel testis. This antibody (anti-spermatogonia-specific antigen-1, anti-SGSA-1) recognized a band of about 38 kDa in Western blot analysis of extracts from eel testis. This antigen was observed by immunohistochemistry only in type-A and early type-B spermatogonia and could not be seen in the late type-B spermatogonia, which appeared after the initiation of spermatogenesis by a single injection of human chorionic gonadotropin. Immunoreactive SGSA-1 was absent in spermatocytes, spermatids, spermatozoa, Sertoli cells, and interstitial Leydig cells. Similarly, this antigen was also detected only in type-A/primary spermatogonia in the testes of two species of teleosts, medaka (Oryzias latipes) and tilapia (Oreochromis niloticus), as well as a toad (Xenopus laevis). These results imply that the disappearance of SGSA-1 in late type-B/secondary spermatogonia is a critical step in the progression of spermatogenesis, and indicate that anti-SGSA-1 is a useful marker for analysis of the molecular mechanism controlling the differentiation of spermatogonia in lower vertebrates.

Susceptibility to idiopathic azoospermia in Japanese men is linked to HLA class I antigen

PURPOSE

Approximately 15 to 20% of infertile men have azoospermia. In the Y chromosome a deletion, termed the azoospermic factor, has been found in some cases of idiopathic azoospermia. We investigate the relationship of factors in autosomal chromosomes (HLA class I antigens) to spermatogenesis failure in idiopathic azoospermia.

MATERIALS AND METHODS

We evaluated 65 infertile Japanese men with idiopathic azoospermia. The frequency of the HLA allele reported in 1,216 healthy Japanese men was used as a control. HLA class I typing was performed by the National Institutes of Health standard serological method or polymerase chain reaction-sequence specific primer analysis. Allele frequencies were calculated. We determined statistical significance in the frequency of each allele in patients and controls using the chi-square test. The relationship of HLA antigens to idiopathic azoospermia was expressed as relative risk.

RESULTS

In Japanese men with idiopathic azoospermia the frequency of HLA-A33, B13 and B44 was significantly increased compared with controls. The relative risk of HLA-B44 was 8.4, an extremely high value compared with that of other diseases and HLA antigens.

CONCLUSIONS

We suggest that HLA class I antigens are important genetic markers that represent a risk factor for idiopathic azoospermia.

The microtubular system and posttranslationally modified tubulin during spermatogenesis in a parasitic nematode with amoeboid and aflagellate spermatozoa

Using transmission electron microscopy and immunologic approaches with various antibodies against general tubulin and posttranslationally modified tubulin, we investigated microtubule organization during spermatogenesis in Heligmosomoides polygyrus, a species in which a conspicuous but transient microtubular system exists in several forms: a cytoplasmic network in the spermatocyte, the meiotic spindle, a perinuclear network and a longitudinal bundle of microtubules in the spermatid. This pattern differs from most nematodes including Caenorhabditis elegans, in which spermatids have not microtubules. In the spermatozoon of H. polygyrus, immunocytochemistry does not detect tubulin, but electron microscopy reveals two centrioles with a unique structure of 10 singlets. In male germ cells, microtubules are probably involved in cell shaping and positioning of organelles but not in cell motility. In all transient tubulin structures described in spermatocytes and spermatids of H. polygyrus, detyrosination, tyrosination, and polyglutamylation were detected, but acetylation and polyglycylation were not. The presence/absence of these posttranslational modifications is apparently not stage dependent. This is the first study of posttranslationally modified tubulin in nematode spermatogenesis.

Comparative studies on the effects of specific immunoneutralization of endogenous FSH or LH on testicular germ cell transformations in the adult bonnet monkey (Macaca radiata)

PROBLEM

It is yet to be determined clearly whether the two hormones FSH and T act synergistically in the same cell type--the Sertoli cells--to control overall spermatogenesis or influence independently the transformation of specific germ cell types during spermatogenesis in the adult mammal.

METHOD

Adult male bonnet monkeys specifically deprived of either FSH or LH using immunoneutralization techniques were monitored for changes in testicular germ cell transformation by DNA flow cytometry.

RESULTS

FSH deprivation caused a significant reduction ( > 40%; P < 0.05) in [3H] thymidine incorporation into DNA of proliferating 2C (spermatogonial) cells, a marked inhibition ( > 50%) in the transformation of 2C to primary spermatocytes (4C) and a concomitant, belated reduction (50%) in the formation of round spermatids (1C). In contrast, specific LH/T deprivation led to an immediate arrest in the meiotic transformation of 4C to 1C/HC leading to an effective and significant block ( < 90%; P < 0.01) in sperm production.

CONCLUSION

Thus, LH rather than FSH deprivation has a more pronounced and immediate effect as the former primarily blocks meiosis (4C --> 1C/HC) which controls production of spermatids. These data provide evidence for LH/T and FSH regulating spermatogenic process in the adult primate by primarily acting at specific germ cell transformation steps.

Development of an antifertility vaccine for pets based on active immunization against luteinizing hormone-releasing hormone

Male dogs and cats were immunized against LHRH in order to evaluate the feasibility of an immunological approach to pet contraception. In the first study, dogs were immunized with 100, 500, or 2500 micrograms of LHRH conjugated to tetanus toxoid. A significant decline in serum testosterone (T) levels was observed in all immunized dogs, reaching castration levels in some animals by Week 4 and remaining suppressed in all the immunized dogs through the course of the study. Testicular histology suggested arrest of spermatogenesis (infertility). The effects of "immunological castration" were reversible (study 2): steroidogenesis suppressed by "immunological castration" was restored as antibody titers declined. Effective antibodies were rapidly reinduced in dogs by a single injection of LHRH1-TT. In contrast, the level of antibodies induced in male cats (study 3) was not sufficient for "immunological castration." The conclusion was that active immunization against LHRH could provide a cost-effective, nonsurgical, reversible means to control the fertility of companion animals.

Immunohistochemical characterization of a stage-specific antigen during oogenesis and spermatogenesis recognized with monoclonal antibody

In order to detect and characterize novel molecules which function in oogenesis, immunohistochemical study using a monoclonal antibody (MAb) raised against oocytes of Xenopus laevis was carried out. The distribution of the detectable molecule with MAb X-80, which specifically reacts with Xenopus previtellogenic oocytes; stages I and II (Dumont, 1972), in particular was analyzed. The hamster, mouse, chick, quail, Caenorhabditis elegans and Lilium longiflorum were also examined. Interestingly MAb X-80 bound not only in Xenopus oocytes but in its secondary spermatocytes and spermatids. Furthermore, MAb X-80 gave a similar staining pattern in the Lilium and other, although the stage when the positive reaction is detectable is different in the male and female germ cells.

Differential expression of complement regulatory proteins decay-accelerating factor (CD55), membrane cofactor protein (CD46) and CD59 during human spermatogenesis

We have examined the distribution of the complement (C) regulatory proteins CD59, membrane cofactor protein (MCP) and decay-accelerating factor (DAF) on mature sperm and compared expression of these proteins in parallel both during spermatogenesis and in the prostate. Enhanced immunoperoxidase staining and radioimmunoassay confirmed that C regulators are differentially expressed on sperm; CD59 was strongly expressed on the surface of acrosome intact sperm while MCP and DAF appear to be located primarily on the inner acrosomal membrane. While the MW of CD59 on sperm is typical of other systems, we confirm that in addition to a novel 40,000-46,000 MW MCP protein, sperm also express a novel 55,000 MW DAF product. Examination of normal testis by immunostaining revealed that although C regulators are differentially expressed within the germinal epithelium, all three proteins were present on the acrosomal region of condensing spermatids. We show that novel, low MW forms of MCP and DAF are expressed in normal testis membranes but are absent from testis membranes obtained from patients undergoing gender reassignment surgery in whom the germinal epithelium is diminished. Novel MW C3 convertase regulators are therefore associated with differentiating germinal epithelium. Typical CD59 components were also present on normal testis membranes confirming that CD59 is acquired during spermatogenesis. We demonstrate that the prostatic epithelium, in addition to MCP, expresses CD59 but not DAF. By comparison with CD59, therefore, our studies suggest that DAF may be acquired only in the testis. Overall, our data suggest that, on leaving the testis, sperm express the repertoire of C regulators required for protection from C during their transit through the male and female reproductive tracts.

A novel stage-specific differentiation antigen is expressed on mouse testicular germ cells during early meiotic prophase

A murine cell surface antigen exhibiting stage-specific expression during spermatogenesis was detected with two monoclonal antibodies (mAbs), designated BC7 and CA12. In mouse testis, these mAbs recognized a small population of cells located near the periphery of seminiferous tubules at stages XII and I-VI, and these spermatogenic cells were identified as zygotene and early pachytene spermatocytes. Expression of the antigens was transient and was not detected in germ cells at more advanced stages of spermatogenesis such as late pachytene spermatocytes and round spermatids. Immunoprecipitation and immunoblotting studies showed that both mAbs CA12 and BC7 reacted with the same antigenic molecule, which had an estimated molecular mass of 95 kDa. CA12/BC7 antigen, detected in plasma membrane fraction, was a glycoprotein with sialic acid residues and had affinity with WGA lectin. Furthermore, intraperitoneal injection of mAb BC7 caused an apparent spermatogenic disturbance in prepubertal mice. These results suggested that CA12/BC7 antigen, a novel cell surface glycoprotein, is an essential molecule that plays an important role during early meiotic prophase of spermatogenesis.

Expression of the proliferation-associated Ki-67 antigen in bovine testicular tubular cells during the seminiferous epithelial cycle, demonstrated with the MIB-1 antibody

Ki-67 expression in the seminiferous tubule of the bovine testis was studied by immunohistochemistry during the seminiferous epithelial cycle using the monoclonal antibody MIB-1. Spermatogonial proliferation is most obvious in stages 5-7, and 8, when B-spermatogonia divide. A lower rate of spermatogonial propagation is observed preceding or during meiosis in stages 1-4. The MIB-1 antibody also gives positive results with some post-spermatogonial tubular cells. Preleptotenes passing through S-phase in stage 1 reveal positive nuclei. During prophase of meiosis I pachytenes react strongly, diplotenes react in an attenuated manner, while leptotenes and zygotenes stay negative. Secondary spermatocytes seen in stage 4 are positive as are the chromosomes during meta- and anaphase of the meiotic divisions. Post-meiotic spermatids are also decorated but stop Ki-67 expression abruptly at the end of stage 4. Sertoli cells are negative.

Stage-specific detection of mRNA for the sperm antigen SP-10 in human testes

SP-10 is a sperm-specific, intra-acrosomal protein that is considered to be a vaccine candidate for immunocontraception. In the present study, in situ hybridization with biotin and 35S labeled riboprobes was used to determine the pattern of SP-10 mRNA expression in human testes. Both methods demonstrated SP-10 mRNA primarily in round spermatids found in stages I, II, and III of the seminiferous cycle. Morphometric analysis of silver grains with the 35S-labeled probe showed less SP-10 mRNA in spermatids at stages IV, V, and VI than in previous stages, and rarely was label found in spermatogonia or spermatocytes. The expression of SP-10 mRNA first appeared at stage I coincident with the appearance of the protein, which was shown previously to persist in the acrosomal matrix throughout spermiogenesis. The decrease in SP-10 mRNA occurred when spermatids underwent polarization, nuclear condensation, and elongation. The appearance of SP-10 mRNA in round spermatids suggests that increases in SP-10 transcription or SP-10 mRNA stability or both occur as spermatids develop from the Golgi phase to the cap phase. The subsequent decline of SP-10 mRNA, despite the persistence of the SP-10 protein in all spermatids, suggests that a decrease in SP-10 transcription or an increase in mRNA degradation occurs when spermatids elongate.

The glycosylphosphatidylinositol-anchored lymphocyte antigen CDw52 is associated with the epididymal maturation of human spermatozoa

The CAMPATH-1 (CDw52) antigen is a small glycosylphosphatidylinositol (GPI) anchored glycoprotein with a mature peptide comprising only 12 amino acids. It is abundantly expressed on human lymphocytes and is an unusually good target for complement-mediated cell lysis. The immunosuppressive and lymphocyte-depleting effects of CAMPATH-1 antibodies are being tested in a variety of diseases. Here we show that the antigen is also expressed at a high level in the male reproductive system, being found in the epididymis, seminal vesicle, seminal plasma and on the surface of mature (but not testicular) spermatozoa. Its possible transfer from epithelial cells in the epididymis to maturing sperm may represent a novel method of acquisition of cell surface antigens. In the presence of human complement, CAMPATH-1 antibodies inhibited the motility of washed sperm. However, seminal plasma blocks antibody binding and can protect sperm from this cytotoxic effect.

AJ-p90: a novel protein of the perinuclear theca in human sperm subacrosome

A perinuclear theca protein of the human sperm subacrosome was detected using LH43 monoclonal antibody which was originally raised against human keratinocytes. Using indirect immunofluorescence, the antibody stained the acrosomal zone (AZ) of dried ejaculated spermatozoa but did not react with viable cells, thus suggesting that the antigen was intracellular. This was confirmed by immunogold electron microscopy which also revealed the ultrastructural localisation of the antigen to the subacrosomal fibrils. Throughout spermatogenesis the antigen was only detected on the AZ of developed testicular spermatozoa and its expression was continued during their epididymal passage. Biochemically, the protein was insoluble in Triton, and dithiothreitol (DTT) was required for its solubilisation. In Western blotting of sperm and keratinocyte lysates, the antibody detected similar 90-kDa protein doublets (AJ-p90). These biochemical features exclude the identity of AJ-p90 with various cyto- and karyo-skeletal antigens, including the intermediate filaments and microfilaments. AJ-p90 therefore represents a novel product of the subacrosomal perinuclear theca. The significance of these data is discussed together with the importance of the antibody for probing the perinuclear theca in normal and abnormal germ cells, including multinucleated spermatids which also showed reactivity with the antibody.

A monoclonal antibody recognizing a differentiation marker on rat gonocytes

Monoclonal antibodies (MAb) were raised against a testicular membrane fraction from 18-day post coitum (p.c.) rat testes. One antibody, designated 4B6.3E10 (mu, kappa), was obtained which specifically reacted with gonocytes in the fetal testis. No significant cross-reactivity with other tissues from the 18-day p.c. embryo was found. MAb 4B6.3E10 was reactive with rat gonocytes from 17-day p.c. until the day of birth. Germ cells at later stages of testis development did not show any labelling. The epitope recognized by 4B6.3E10 is a carbohydrate as periodate treatment leads to a loss of reactivity of the antibody. By SDS-PAGE and Western blotting of proteins extracted from a testicular membrane fraction from 18-day p.c. testes, MAb 4B6.3E10 was found to recognize at least 3 protein moieties with apparent molecular weights in the ranges of 80-100, 120, 160-180 kDa (either under reducing- or non-reducing conditions). The results suggest that MAb 4B6.3E10 recognizes a specific differentiation marker for fetal rat gonocytes.

Characterization of male meiotic germ cell-specific antigen (Meg 1) by monoclonal antibody TRA 369 in mice

We have identified a male meiotic germ cell-specific antigen (Meg 1) with monoclonal antibody (mAb) TRA 369 in mice. The Meg 1 antigen was strongly expressed in specific steps of meiotic germ cells from pachytene spermatocyte to early spermatid, and not in other germ cells or somatic cells. Immunohistochemical examination revealed that the antigen was localized to the cytoplasm and was not distributed in the nucleus or on the cell surface. This antigen was demonstrated to have a molecular weight of 93 kDa and an isoelectric point of 5.2 by Western blotting. This molecule was first detected in the testis of 13-day-old mouse when pachytene spermatocytes first appeared. Thus this is a differentiation-specific antigen in male meiotic germ cells, and mAb TRA 369 is a useful tool to study the regulation of germ cell differentiation and to define germ cell development in a molecular level.

Molecular and developmental studies of a sperm acrosome antigen recognized by HS-63 monoclonal antibody

A conserved mouse sperm antigen (MSA-63) recognized by a monoclonal antibody (HS-63) was isolated from mouse testes by single-step immunoaffinity chromatography. Isolated MSA-63 preparation was shown to be a group of proteins ranging from 24-84 kDa and with isoelectric points (pIs) ranging from 4.0-6.0 when analyzed by two-dimensional (2-D) gel electrophoresis. Microsequencing techniques were employed to determine the relationships of various protein spots on 2-D gels. Partial amino acid sequences of some protein spots in isolated MSA-63 preparation were shown to be homologous to mouse actins, while others revealed homology only to the SP-10 protein. Rabbit antisera raised against isolated MSA-63 antigen preparation were used to immunoscreen a mouse testis cDNA library. Isolated cDNA clones carrying a 1.2-kb insert were used to obtain nucleotide sequences containing open-reading frames and to deduce the corresponding amino acid sequence of MSA-63. A high degree of homology was observed between MSA-63 and a known human sperm antigen, SP-10, at DNA/protein levels. Amino acid sequences of tryptic peptides derived from protein spots of 24-47 kDa and pIs of 4.2-4.4 were found to be identical to those deduced from isolated cDNA clones. The gene expression of MSA-63 during spermatogenesis in mice was studied using a specific cDNA probe as well as HS-63. It was observed that MSA-63 was not expressed until the postmeiotic stages of spermatogenesis.

Localization of post-vasectomy sperm autoantigens in the Lewis rat

Major rat sperm autoantigens of 86, 63, 43, 28 and 20 kDa are recognized by post-vasectomy and hyperimmunization antisera from the Lewis rat (Handley et al., Biol. Reprod. 39 (1988) 1239-1250). In the present study, affinity purified monospecific isoantibodies to each autoantigen were produced by elution from antigens which had been separated by SDS-PAGE and transferred to nitrocellulose. Western blot analysis confirmed a singular specificity for the 63, 28 and 20 kDa antisera and demonstrated some cross reactivity between the 86 kDa and the 43 kDa antisera. The polyclonal antiserum from which the monospecific antisera were produced stained the entire spermatozoon, while monospecific antibodies bound only to the sperm tail, staining the proximal portion (43 and 28 kDa), a distal domain (63 kDa), or the entire tail (86 kDa). Immunohistochemically stained sections of normal rat testes revealed that the 63, 43 and 28 kDa autoantigens were synchronously expressed in the cytoplasm of spermatids in the apical portions of seminiferous tubules during stages II-VIII in the cycle of the seminiferous epithelium. The 86 kDa autoantigen showed little or no staining in testis sections, implying that this autoantigen appeared on mature sperm following spermiation. These and other data suggest that a highly polymeric structure, possibly within the outer dense fibers of the tail, is a dominant sperm autoimmunogen following vasectomy of the Lewis rat.

Male antigen defined serologically does not identify a factor responsible for testicular development

To test the proposal that the serologically detected male antigen (SDMA; which may or may not be the same as H-Y) was responsible for triggering the indifferent gonad to differentiate into the testis in mammals, H-Y negative sex-reversed XXSxr' male mice were investigated for the presence of SDMA. Serum from C57BL/6 female mice immunized against tissue from XXSxr' males did not contain SDMA specific antibody as detected by the complement-mediated sperm cytotoxicity assay. Thus, although SDMA is a male-specific factor and may play a role in male sex determination, it does not identify the testis-determining factor (TDF).

Localization of sperm antigen SP-10 during the six stages of the cycle of the seminiferous epithelium in man

The distribution of the sperm protein SP-10 was investigated in plastic-embedded samples of human testes by light and electron microscopy. An immunogold and silver enhancement technique, in conjunction with a monoclonal antibody (MHS-10) raised against SP-10, was used to localize the protein. SP-10 was detected in spermatids at each of the six stages of the cycle of the seminiferous epithelium. Light microscopy showed immunoreactive material at the circumference of developing acrosomes in the early steps of spermiogenesis. As differentiation proceeded and cell shape changed from round to elongated, immunoreactive material appeared in an arc, which gradually became a V shape bordering the spermatid nucleus. The area of the immunoreactive material and its shape corresponded to that of the developing acrosome. At the electron microscopic level, gold particles indicative of the presence of SP-10 were detected on electron-dense material found within the developing acrosomal vesicle in early steps of spermiogenesis. As the electron density of the acrosome increased, a high concentration of gold particles was seen in the vesicle matrix. The gold particles gradually became associated with the inner and outer acrosomal membranes of the most mature spermatids.

A new murine model of autoimmune orchitis induced by immunization with viable syngeneic testicular germ cells alone. I. Immunological and histological studies

Experimental autoimmune orchitis (EAO) was produced in C3H/He mice with as high as 100% incidence by two or three s.c. injections of 1 x 10(7) viable syngeneic testicular germ cells (TC) without resorting to adjuvants, Bordetella pertussis vaccine, or other immunological manipulations. On day 40 after the first injection of TC, the lesions induced were characterized by interstitial infiltration of inflammatory cells and severe hypospermatogenesis in the testis with resulting whole organ atrophy and, in contrast, by a complete lack of epididymitis. Immunological studies revealed that this form of immunization caused both delayed-type hypersensitivity and humoral antibody responses to syngeneic TC. We compared the susceptibilities to the induction of this type of EAO among six different strains of inbred mice comprising A/J, AKR, BALB/c, C3H/He, C57BL/6 and DBA/2 mice. All strains except for DBA/2 mice developed lesions of EAO to a greater or lesser extent, and severe disease was induced with high frequency in two strains, C3H/He and A/J. As this murine model of EAO can be induced without the use of Freund's complete adjuvant and B. pertussis vaccine, it is simply 'autoimmune' in nature and may provide new ways for further investigation into the immunological mechanisms which regulate deleterious autoimmune reactions to germ cell antigens leading to the male infertility.