Spermatogenic Disturbance Research Articles

Effects of Liver-Regulating Herb Compounds on Varicocele-Associated Testicular Dysfunction Through Restoring Hormones and Spermatocytes Apoptosis.

Varicocele is considered as one of the causes for male infertility. Though varicocelectomy is suppose to improve semen parameters in adult infertile men, some patients with varicocele were still infertile after varicocelectomy.. Previous studies showed Traditional Chinese Medicine, Liver-regulating herb compounds (LRHC) could improve the semen quality and increase fertility rates of infertile patients with varicocele. This study aimed to throw light on the mechanism of LRHC on varicocele-associated infertility. Materials and methods: Rats with varicocele-induced were treated with LRHC at dosage of 1mL/100g by intragastric administration for 90 days. The effects of LRHC on hormones and spermatocytes apoptosis were examined using ELISA assay, Western blotting, and flow cytometry. Rats induced with varicocele showed higher level of follicle stimulating hormone (FSH) in serum, which was brought back to normal level by LRHC. After treating with LRHC, both testicular tissue in vivo and Sertoli cell TM4 cells in vitro showed elevated expressions of FSHR. Cell viabilities of TM4 cells and spermatocyte GC-2 cells were improved by LRHC treatment under normoxia and hypoxia condition. Moreover, LRHC protected GC-2 cells from apoptosis induced by hypoxia. The expression of Bax reduced, while that of Bcl-2 increased after treating with LRHC. This study revealed that LRHC had protective effects on spermatogenic disturbance caused by varicocele through regulating hormones and reducing spermatogenic cell apoptosis under hpoxia condition.

OP-2 - HSPA4L and GIT1 as possible biomarkers in testicular autoimmunity

Clinically, 60–75% of male infertility cases are categorized as idiopathic spermatogenic disturbance. In previous studies, lymphocytic infiltration and immune deposits were present in several testis biopsy specimens, indicating that immunological factors contribute to the occurrence of the idiopathic spermatogenic disturbance. We recently found that immunization of A/J male mice with heat shock protein family A member 4 like (HSPA4L) and G protein-coupled receptor kinase interacting protein-1 (GIT1) induces experimental autoimmune orchitis (EAO). In this study, we detected autoantibodies and lymphocyte activity to investigate whether these autoimmunogenic antigens could be biomarkers for EAO. A/J male mice, 8 weeks old, were subcutaneously injected twice with TGC, to induce EAO and injected with HBSS alone were used as controls. The spleen cells and sera of control mice and TGC-immunized mice were analyzed by ELISA assay and lymphocyte stimulation test. In the result, lymphocyte proliferation was significantly stimulated in vitro by GIT1 (100 μg) and HSPA4L (10, 50, 100, and 200 μg) in TGC immunized mice. In addition, the sera of TGC-immunized mice contained more anti-GIT1 and anti-HSPA4L antibodies than did the serum of control mice. Therefore, the detection of immune responses against HSPA4L and GIT1 may be useful parameters of immunologic male infertility.

Research Progress on the Relationship between Obesity-Inflammation-Aromatase Axis and Male Infertility.

Aromatase is a key enzyme in the transformation of androgen into estrogen. Its high expression will destroy the hormonal balance in the male body, and the excessive transformation of androgen into estrogen in the body will further damage the spermatogenic function of the testis, affect the normal development of the sperm, and cause spermatogenic disturbance. Adipose tissue has a high expression of aromatase and shows high enzymatic activity and ability to convert estrogen. Adipose tissue is the most estrogen-producing nongonadal tissue in the body because of its large size, accounting for about 20% of the body mass in healthy adults. PPARγ is recognized as the key adipose differentiation in the transcriptional regulation of the transcription factor. In the process of adipocyte differentiation, PPARγ regulate the expression of aromatase. The increase of aromatase is associated with the inflammatory response in adipose tissue caused by obesity. After obesity, the increase of proinflammatory factors in adipocytes will lead to enhanced transcription of the CYP19 gene encoding aromatase in adipocytes, which in turn will lead to increased expression of aromatase in adipocytes. This article reviews the regulation of male sterility from the angle of the “obesity-inflammation-aromatase” axis.

Low-dose exposure to di-(2-ethylhexyl) phthalate (DEHP) increases susceptibility to testicular autoimmunity in mice

Exposure to di-(2-ethylhexyl) phthalate (DEHP) induces spermatogenic disturbance (SD) through oxidative stress, and affects the immune system by acting as an adjuvant. Recently, we reported that in mice, a low dose of DEHP, which did not affect spermatogenesis, was able to alter the testicular immune microenvironment. Experimental autoimmune orchitis (EAO) can be induced by repeated immunization with testicular antigens, and its pathology is characterized by production of autoantibodies and SD. In the present study, we investigated the effect of a low-dose DEHP on the susceptibility of mice to EAO. The exposure to DEHP-containing feed (0.01%) caused a modest functional damage to the blood–testis barrier (BTB) with an increase in testicular number of interferon gamma (IFN-γ)-positive cells and resulted in the production of autoantibodies targeting haploid cells, but did not affect spermatogenesis. While only single immunization with testicular antigens caused very mild EAO, the concurrent DEHP exposure induced severe EAO with significant increases in number of interferon gamma-positive cells and macrophages, as well as lymphocytic infiltration and serum autoantibody titer accompanied by severe SD. To summarize, the exposure of mice to the low-dose DEHP does not induce significant SD, but it may cause an increase in IFN-γ positive cells and modest functional damage to the BTB in the testis. These changes lead to an autoimmune response against haploid cell autoantigens, resulting in increased susceptibility to EAO.

Prevention of preterm labor by omega-3 polyunsaturated fatty acids and resolvin E3

necrosis of testicular tissues in mice and rats treated with high doses. Recently, it also became evident that cadmium can affect the integrity of the blood–testis barrier (BTB), the endocrine function of Leydig cells, apoptosis of germ cells and systemic immunity, even on treatment with a low dose that does not induce spermatogenic disturbance. Experimental autoimmune orchitis (EAO), i.e., an organ-specific autoimmunity of the testis, can be induced by repeated immunization with testicular antigens, and its pathology is characterized by lymphocytic inflammation and spermatogenic disturbance. In the present study, we investigated the morphological and functional changes of testes in mice treated with a low dose of cadmium chloride (CdCl2) and also examined its toxicity as to susceptibility to EAO. The results showed that exposure to 3mg CdCl2/kg body weight did not affect the spermatogenic state. However, the BTB at the tubuli recti and the rete testis, but not the seminiferous tubules, was slightly weakened, and intra-testicular mRNA expression of IL-6, TNFand IL-1 was significantly increased by the CdCl2 treatment. Furthermore, immunization with testicular antigens after the CdCl2 exposure significantly augmented the EAO severity. Therefore, exposure to a low dose of CdCl2 induces no significant disturbance of spermatogenesis, however, it does change the immunological microcircumstances in the testis, resulting in increased susceptibility to testicular autoimmunity.

Contribution of IL-12/IL-35 common subunit p35 to maintaining the testicular immune privilege.

The testis is an organ with immune privilege. The comprehensive blood–testis barrier formed by Sertoli cells protects autoimmunogenic spermatozoa and spermatids from attack by the body’s immune system. The interleukin (IL)-6/IL-12 family cytokines IL-12 (p35/p40), IL-23 (p19/p40), IL-27 (p28/Epstein-Barr virus−induced gene 3 [EBI3]), and IL-35 (p35/EBI3) play critical roles in the regulation of various immune responses, but their roles in testicular immune privilege are not well understood. In the present study, we investigated whether these cytokines are expressed in the testes and whether they function in the testicular immune privilege by using mice deficient in their subunits. Expression of EBI3 was markedly increased at both mRNA and protein levels in the testes of 10- or 12-week-old wild-type mice as compared with levels in 2-week-old mice, whereas the mRNA expression of p40 was markedly decreased and that of p35 was conserved between these two groups. Lack of EBI3, p35, and IL-12 receptor β2 caused enhanced infiltration of lymphocytes into the testicular interstitium, with increased interferon-γ expression in the testes and autoantibody production against mainly acrosomal regions of spermatids. Spermatogenic disturbance was more frequently observed in the seminiferous tubules, especially when surrounded by infiltrating lymphocytes, of these deficient mice than in those of wild-type mice. In particular, p35-deficient mice showed the most severe spermatogenic disturbance. Immunohistochemical analyses revealed that endothelial cells and peritubular cells in the interstitium were highly positive for p35 at both ages, and CD163+ resident macrophages positive for p35 and EBI3, possibly producing IL-35, were also detected in the interstitium of 12-week-old mice but not those of 2-week-old mice. These results suggest that p35 helps in maintaining the testicular immune privilege, in part in an IL-35-dependent manner.

Neonatal exposure to diethylstilbestrol causes granulomatous orchitis via epididymal inflammation

Diethylstilbestrol (DES), an endocrine-disrupting chemical, is an infamous artificial estrogenic compound. Although neonatal exposure to DES has been shown to result in inflammation of the male reproductive system, it has not, to our knowledge, been reported to induce testicular inflammation. Here we report that neonatal exposure to DES caused granulomatous orchitis with spermatogenic disturbance in 4 of 17 ICR male mice at 12weeks of age. In the animals with spermatogenic disturbance, we observed either seminiferous tubules containing only cells with Sertoli cell features (likely Sertoli cell syndrome), or tubule cells in maturation arrest that contained only spermatogonia and/or spermatocytes. Following neonatal DES exposure, 5-week-old mice exhibited inflammation in cauda epididymis; by 8weeks, the inflammation had spread to all segments of epididymis but not the testis; by 12weeks, inflammation of the epididymis was observed in all mice. These data indicated that cauda epididymis has increased sensitivity to neonatal DES exposure compared to other segments of epididymis and testis. The data also implied that neonatal DES exposure-induced inflammation in cauda epididymis extended gradually to the testis via corpus and caput during development.

Neonatal estrogen treatment with β-estradiol 17-cypionate induces in post-pubertal mice inflammation in the ductuli efferentes, epididymis, and vas deferens, but not in the testis, provoking obstructive azoospermia

Neonatal estrogen treatment (NET) induces morphological changes in male reproductive organs. NET with β-estradiol 17-cypionate is reported to induce inflammation with stromal-epithelial abnormalities in the prostate and seminal vesicles in post-pubertal mice. The aim of this study was to investigate the histopathology of the testis, ductuli efferentes, epididymis, and vas deferens in mice after NET with β-estradiol 17-cypionate. No morphological changes in these organs were observed until 4weeks after NET. However, some inflammatory cells were found in epididymis and vas deferens 6weeks after NET. Eight weeks after NET, inflammatory cells spread to the ductuli efferentes and inflammation was severe from 6 to 12weeks after NET. Inflammatory cells were never seen in the whole testis, but cystic dilatation of the rete testes with spermatogenic disturbance was found around the mediastinum testis. Many inflammatory cells emigrated into the lumen of the epididymis, resulting in complete absence of spermatozoa in the vas deferens. Most of the inflammatory cells penetrating into the epithelial layers of epididymal ducts were neutrophils. These results indicate that in post-pubertal mice, NET with β-estradiol 17-cypionate induces inflammation in the ductuli efferentes, epididymis, and vas deferens, but not in the testis, provoking obstructive azoospermia.

Inhibin B as a Marker of Sertoli Cell Damage and Spermatogenic Disturbance in the Rat

This study was designed to determine the effects of Compound A on spermatogenesis including assessment of inhibin B levels and on fertility in the male rat over a 15 to 19 weeks treatment and a 19 weeks treatment-free period in control and 30, 60, and 180 mg/kg dose groups (n = 22/group). Compound A in a dose-dependent manner induced various degrees of spermatogenic alterations compatible with Sertoli cells being the primary target, for example, inter- and intracellular Sertoli cell vacuolization and altered cellular morphology followed by germ cell degeneration and marked reduction of epididymidal sperm numbers. Blood-testis barrier remained intact (electron microscopy and hyperosmotic fixation test) until germ cells disappeared. Mating behavior and weights of androgen-dependent prostate and seminal vesicles remained unaffected. Inhibin B levels correlated only with moderate to severe spermatogenic alterations. Ten animals with inhibin B levels below detection limit were encountered and five of these animals were fertile in week 19 but following 19 weeks without treatment, another five animals were rendered infertile and inhibin B levels remained undetectable. In the rat, inhibin B only reflects major spermatogenic alterations and markedly reduced inhibin B levels might indicate irreversibility of these alterations and even infertility.

Effects on the Local Immunity in the Testis by Exposure to Di-(2-ethylhexyl) Phthalate (DEHP) in Mice

Exposure to di-(2-ethylhexyl) phthalate (DEHP) has been reported to induce spermatogenic disturbance through oxidant stress and affect the immune system as an adjuvant. However, the effect of DEHP on the testicular immune microenvironment has not yet been investigated. In the present study, we examined the testicular immune microenvironment after exposure to doses of DEHP, previously identified as no-observed-adverse-effect levels. Adult male mice were administered food containing 0%, 0.01% or 0.1% DEHP and then testes were analyzed. The results showed that a slight but significant spermatogenic disturbance appeared in the 0.1% DEHP group but not in the 0.01% DEHP group at 8 weeks. It was also demonstrated that lymphocytes and F4/80- and MHC class II- positive cells were significantly increased with the elevation of IL-10 and IFN-γ mRNA expressions in the testes of not only the 0.1% DEHP group but also the 0.01% DEHP group at 8 weeks. Histochemical analyses involving horseradish peroxidase (HRP) as a tracer showed that a little blood-borne HRP had infiltrated into the lumen of a few seminiferous tubules beyond the blood-testis-barrier in both the 0.1% and 0.01% DEHP groups at 8 weeks. This indicates that a dose of DEHP that has little effects on spermatogenesis can change the testicular immune microenvironment with functional damage of the blood-testis barrier.

The Effects of Adjuvants on Autoimmune Responses Against Testicular Antigens in Mice

Experimental autoimmune orchitis (EAO) is a model of immunologic male infertility and pathologically characterized by lymphocytic inflammation, which causes breakdown of the testicular immune privilege with spermatogenic disturbance. Generally, murine EAO is induced by immunization with testicular homogenate (TH) from the testes of donor mice + complete Freund's adjuvant (CFA) + Bordetella pertussigens (BP), and it has been considered that treatment with these two adjuvants is required to enhance the immune response against testicular antigens. However, there remains a possibility that CFA and BP may affect autoimmune responses against the testicular antigens without TH. In the present study, we examined this possibility using real-time RT-PCR, Western blotting and immunohistochemical staining. The results demonstrated that immunization with TH in combination with CFA and BP evoked more severe EAO than that with only TH. Real-time RT-PCR analyses revealed that Fas mRNA expression in TH+CFA+BP-induced EAO was significantly higher than that in TH-induced EAO. Interestingly, IL-6 mRNA expression dramatically increased in TH+CFA+BP-induced EAO; however, no apparent change in IL-6 mRNA expression occurred in TH-induced EAO. It was also noted that treatment with CFA and BP alone augmented autoimmune reactions against some testicular autoantigens. These results indicates that these adjuvants are helpful in evoking severe EAO, and treatment with the adjuvants alone can evoke autoimmune reactions against some testicular autoantigens despite the use of no TH.

Experimental autoimmune orchitis as a model of immunological male infertility

Clinically, 60-75% of male infertility cases are categorized as idiopathic spermatogenic disturbance. In previous studies of this condition, lymphocytic infiltration and immune deposits were present in several testis biopsy specimens, indicating that inflammatory or immunological factors contribute to the occurrence of the lesions. However, there is currently little evidence regarding immunological infertility in men. Previously, we established an immunological infertility model, experimental autoimmune orchitis (EAO), that can be induced in mice by two subcutaneous injections of viable syngeneic testicular germ cells without the use of any adjuvant. In this EAO model, lymphocytes surround the tubuli recti and then induce spermatogenic disturbance. In addition, after the active inflammation stage of this model, the seminiferous epithelium is damaged irreversibly, resembling the histopathology of human male idiopathic spermatogenic disturbance. In the majority of patients with testicular autoimmunity, there is a chronic and asymptomatic development of the inflammatory reaction. Therefore, this disease is very difficult to diagnose at the ongoing stage, and it is possible that the histopathology of idiopathic spermatogenic disturbance in the clinic is reported at the post-active inflammation stage of autoimmune orchitis. In this review, the histopathology of EAO before and after inflammation is discussed, comparing it with human orchitis.

Postinflammation stage of autoimmune orchitis induced by immunization with syngeneic testicular germ cells alone in mice

We previously established an immunological infertility model, experimental autoimmune orchitis (EAO), which can be induced by two subcutaneous injections of viable syngeneic testicular germ cells on days 0 and 14 in mice without using any adjuvant. In this EAO model, CD4+ T-cell-dependent lymphocytic infiltration and immune deposits were found with spermatogenic disturbance on day 120. However, the late stage of EAO (= postactive inflammation stage on day 365) has not yet been investigated. Therefore, we investigated the histopathological characteristics of the late stage. The results revealed that the lymphocytic infiltration finally resolved; however, the seminiferous epithelium persistently showed maturation arrest and the Sertoli cell-only feature. In the seminiferous tubules showing maturation arrest, both proliferation and apoptosis of germ cells had occurred simultaneously. It was also noted that there were deposits of immunoglobulin G and the third component of complement on the thickened basement membrane of seminiferous tubules in the late stage of EAO. These results indicate that histopathology after active inflammation in EAO comprises persistent damage to the seminiferous epithelium and may resemble the histopathology of "idiopathic disturbance of spermatogenesis" in man.

Cadmium exposure increases susceptibility to testicular autoimmunity in mice

Cadmium, one of various environmental toxicants, is known to suppress systemic immunity and to injure the testicular capillary endothelia with resultant necrosis of testicular tissues in mice and rats treated with high doses. Recently, it also became evident that cadmium can affect the integrity of the blood-testis barrier (BTB), the endocrine function of Leydig cells, apoptosis of germ cells and systemic immunity, even on treatment with a low dose that does not induce spermatogenic disturbance. Experimental autoimmune orchitis (EAO), i.e., an organ-specific autoimmunity of the testis, can be induced by repeated immunization with testicular antigens, and its pathology is characterized by lymphocytic inflammation and spermatogenic disturbance. In the present study, we investigated the morphological and functional changes of testes in mice treated with a low dose of cadmium chloride (CdCl2 ) and also examined its toxicity as to susceptibility to EAO. The results showed that exposure to 3 mg CdCl2 kg(-1) body weight did not affect the spermatogenic state. However, the BTB at the tubuli recti and the rete testis, but not the seminiferous tubules, was slightly weakened, and intra-testicular mRNA expression of interleukin (IL)-6, tumor necrosis factor-α and IL-1β was significantly increased by the CdCl2 treatment. Furthermore, immunization with testicular antigens after the CdCl2 exposure significantly augmented the EAO severity. Therefore, exposure to a low dose of CdCl2 induces no significant disturbance of spermatogenesis, however, it does change the immunological microcircumstances in the testis, resulting in increased susceptibility to testicular autoimmunity.

Experimental model of autoimmune orchitis with abdominal placement of donor's testes, epididymides, and vasa deferentia in recipient mice

Haploid germ cells (spermatids and spermatozoa) develop in the testis after immune tolerance has been established. Therefore, they contain various autoimmunogenic antigens, but the testis is known to be an immunologically privileged organ. In particular, the blood-testis barrier formed by Sertoli cells protects autoimmunogenic haploid germ cells from attack by the autoimmune system. Experimental autoimmune orchitis (EAO), a breakdown of the testicular immune privilege leading to immunological male infertility, has been ordinarily induced in mice by immunization twice with testicular antigens+complete Freund's adjuvant (CFA)+Bordetella pertussis (BP). We previously found that two subcutaneous injections of viable syngeneic testicular germ cells induced murine EAO without the use of CFA+BP. In both EAO models, the lesions are characterized by spermatogenic disturbance with lymphocytic inflammation, and a second immunization with testicular antigens is critical for the disease induction. In the present study, we found that only one placement of a syngeneic donor's testes, epididymides and vasa deferentia (TEV) into the abdominal cavity or subcutaneous space was sufficient to induce EAO on the recipient's testes in mice. It was also noted that the placement of TEV induced only orchitis without epididymo-vasitis, while the serum autoantibodies were reactive with haploid germ cells existing throughout the TEV. Furthermore, the TEV placed in the abdominal cavity rather than the subcutaneous space was effective in inducing severe EAO, and the A/J strain was most susceptible to the TEV-induced EAO among the three strains examined. The model of EAO induced by the placement of the donor's TEV into the abdominal cavity in A/J mice will be helpful for the further analyses of testicular autoimmunity.

Stereological Analysis of Peritubular Cells in Aging Mouse Testes

Objective To analyse quantitative changes of testicular peritubular cells in aging mice, and meanwhile investigate age-related changes in both Sertoli cells and germ cells with stereology. Methods Thirty male Kunming mice were enrolled in this study. The aged mice (n=15) were 18 months old. The young mice (n=15) were 6 months old, as the control. Haematoxylin and eosin staining was used to observe histological changes. Pathological evaluation rules of assignment scores were made to evaluate. Stereology techniques were applied to quantitatively analyse histological structure of the testicular tissues. Results Compared with young group, pathologic assignment scores of aging group were significantly higher (P 0.05). Conclusion The pathological assignment scores suggest a succession of changes on the testis with age. The stereological numbers demonstrate damaged Sertoli cells and decreased germ cells, which is indicative of spermatogenic disturbance. However, no significant quantity changes of peritubular cells is observed in aging mice.

Intratesticular Expression of mRNAs of Both Interferon γ and Tumor Necrosis Factor α is Significantly Increased in Experimental Autoimmune Orchitis in Mice

Experimental autoimmune orchitis (EAO) is one of the models of immunological male infertility. Murine EAO is CD4+T cell-dependent and classically induced by immunization with a testicular homogenate and adjuvants. We previously established that immunization with viable syngeneic testicular germ cells (TGC) can also induce murine EAO with no use of any adjuvant. Analyses of this EAO model have already revealed that cultured spleen cells of immunized mice secreted interferon (IFN)-γ and that treatment of the immunized mice with anti-IFN-γ monoclonal antibodies significantly suppressed the EAO. It is known that both IFN-γ and tumor necrosis factor (TNF)-α are representative cytokines of Th1 cells and exhibit local toxicity toward the seminiferous epithelium in vivo. However, changes in these two cytokines in EAO-affected testes have not yet been investigated. Therefore, in the present study, we investigated the expression of intratesticular IFN-γ and TNF- α mRNAs in TGC-induced EAO using real-time RT-PCR. The results demonstrated that the intratesticular mRNAs for both IFN-γ and TNF-α significantly increased, while other cytokines such as IL-1α, IL-1β, IL-6 and TGF-β did not show dramatic changes in the immunized mice. These results suggest that secretion of significant amounts of IFN-γ and TNF-α in situ contributes to the spermatogenic disturbance in EAO.

Histopathology of the tubuli recti at the start of experimental autoimmune orchitis in mice

We previously established an experimental model of autoimmune orchitis (EAO) by means of immunization with testicular germ cells (TGC) alone in mice and confirmed that the disease can be transferred to mice that had received CD4+ but not CD8+ or B lymphocytes obtained from TGC-immunized donor mice. The tubuli recti (TR) are special in that lymphocytes first accumulate around them before spreading to the peripheral seminiferous tubules in EAO. However, the minute changes in the TR remain unknown. Therefore, we investigated the histopathology of the TR before the induction of spermatogenic disturbance. The results revealed that the first infiltrating lymphocytes around the TR were not only of T-cell but also of B-cell lineage. Moreover, it was also shown that some of these infiltrating lymphocytes migrated into the TR, with resultant degeneration of the TR epithelium before damage to the seminiferous epithelium. These findings indicate that TR epithelial cells are the first targets of autoreactive T and B lymphocytes in EAO.

Effect of unilateral testicular rupture on histopathology and germ cell delayed-type hypersensitivity in C3H/He and A/J mice

Contralateral orchitis induced by unilateral testicular injury has been reported as sympathetic orchitis in men and experimental animals. In mice, experimental sympathetic orchitis (ESO) was first demonstrated in the C3H/He strain after experimental testicular trauma. Delayed-typed hypersensitivity (DTH) to testicular germ cells is induced by testicular trauma and treatment with cyclophosphamide before the trauma further enhances anti-testicular germ cell DTH. In the present study we investigated ESO induction with or without cyclophosphamide pretreatment in two murine strains, C3H/He and A/J mice, that are susceptible to testicular autoimmunity. The results show that traumatized testes undergo early degeneration of the seminiferous epithelium followed by neutrophilic inflammation and later fibrosis with little lymphocytic infiltration, in both murine strains. In the contralateral testes, ESO characterized by both lymphocytic inflammation and spermatogenic disturbance was induced in both strains. However, the incidence and severity of ESO in A/J mice tended to be higher than in C3H/He mice. In contrast, cyclophosphamide pretreatment significantly augmented both pathological stages of ESO and anti-testicular germ cell DTH in C3H/He mice, while those in A/J mice were fully developed by testicular rupture alone and were not further augmented by cyclophosphamide pretreatment. We conclude that A/J mice are more sensitive to trauma-induced testicular autoimmunity than C3H/He mice.

Caput epididymitis but not orchitis was induced by vasectomy in a murine model of experimental autoimmune orchitis

Immunization of mice with viable syngeneic testicular germ cells (TGC) alone can induce autoimmune responses against autoantigens of both round and elongating spermatids, resulting in the development of experimental autoimmune orchitis (EAO). Histological lesions in this EAO model without an adjuvant are characterized by lymphocytic infiltration into the testes, spermatogenic disturbance, and a complete lack of epididymitis. In this study, we investigated the effects of vasectomy (Vx) on TGC-induced EAO expecting that Vx augments the severity of testicular inflammation in A/J mice. The results showed that mice receiving Vx alone exhibited no significant inflammatory cell response in either the testes or epididymides, and mice receiving shamVx+TGC immunization had EAO with no epididymitis. In sharp contrast, no EAO was found in the testes of any mice receiving Vx+TGC immunization. Instead, caput epididymitis involving CD4+T cells, CD8+T cells, B cells, and macrophages were induced in them with striking elevation of the tissue levels of both IL6 and IL10 mRNA. Furthermore, serum autoantibodies induced by shamVx+TGC immunization were reactive with both round (immature) and elongating (mature) spermatids; however, those induced by Vx+TGC immunization were specific to acrosomes of mature spermatids and spermatozoa. These unexpected results indicate that Vx may induce the mode by which autoreactive lymphocytes gain access to TGC autoantigens in the epididymides, leading to autoimmune responses against the autoantigens of mature rather than immature spermatids.