Autoimmune Orchitis Research Articles

Seminal plasma S100A8/A9 as a potential biomarker of genital tract inflammation.

Infections and inflammatory reactions in the male genital tract are the leading causes of male infertility with a prevalence of 6%-10%, primarily affecting testicular and epididymal function and ultimately compromising sperm quality. However, most infertile patients with genital infection/inflammation are asymptomatic and easily overlooked. Traditional indicators, including white blood cells, elastase, and other components in semen, can reflect inflammation of the genital tract, but there is still a lack of a uniform standard method of detection. Therefore, it is necessary to explore reliable markers in semen that reflect the inflammatory status of the genital tract. Using the experimental autoimmune orchitis (EAO) model to simulate noninfectious chronic orchitis, we successfully collected ejaculated seminal fluid from EAO rats using optimized electrical stimulation devices. Proteomic analysis was performed using isobaric tags for relative and absolute quantification (iTRAQ). Compared to the control group, 55 upregulated and 105 downregulated proteins were identified in seminal plasma samples from the EAO group. In a preliminary screening, the inflammation-related protein S100A8/A9 was upregulated. We further verified that S100A8/A9 was increased in seminal plasma and highly expressed in testicular macrophages of the EAO model. In patients with oligoasthenospermia and genital tract infections, we also found that S100A8/A9 levels were remarkably increased in seminal plasma and testicular macrophages. S100A8/A9 in semen may be a potential biomarker for chronic genital inflammation. Our study provides a new potential biomarker for early diagnosis and further understanding of male infertility caused by genital inflammation.

Impaired Spermatogenesis in Infertile Patients with Orchitis and Experimental Autoimmune Orchitis in Rats.

Experimental autoimmune orchitis (EAO) is a well-established rodent model of organ-specific autoimmunity associated with infertility in which the testis immunohistopathology has been extensively studied. In contrast, analysis of testis biopsies from infertile patients associated with inflammation has been more limited. In this work, testicular biopsies from patients with idiopathic non-obstructive azoospermia diagnosed with hypospermatogenesis (HypoSp) [mild: n = 9, and severe: n = 11], with obstructive azoospermia and complete Sp (spermatogenesis) (control group, C, n = 9), and from Sertoli cell-only syndrome (SCOS, n = 9) were analyzed for the presence of immune cells, spermatogonia and Sertoli cell (SCs) alterations, and reproductive hormones levels. These parameters were compared with those obtained in rats with EAO. The presence of increased CD45+ cells in the seminiferous tubules (STs) wall and lumen in severe HypoSp is associated with increased numbers of apoptotic meiotic germ cells and decreased populations of undifferentiated and differentiated spermatogonia. The SCs showed an immature profile with the highest expression of AMH in patients with SCOS and severe HypoSp. In SCOS patients, the amount of SCs/ST and Ki67+ SCs/ST increased and correlated with high serum FSH levels and CD45+ cells. In the severe phase of EAO, immune cell infiltration and apoptosis of meiotic germ cells increased and the number of undifferentiated and differentiated spermatogonia was lowest, as previously reported. Here, we found that orchitis leads to reduced sperm number, viability, and motility. SCs were mature (AMH-) but increased in number, with Ki67+ observed in severely damaged STs and associated with the highest levels of FSH and inflammatory cells. Our findings demonstrate that in a scenario where a chronic inflammatory process is underway, FSH levels, immune cell infiltration, and immature phenotypes of SCs are associated with severe changes in spermatogenesis, leading to azoospermia. Furthermore, AMH and Ki67 expression in SCs is a distinctive marker of severe alterations of STs in human orchitis.

Alterations of small non-coding RNA in the spermatozoa of mice with paternal experimental autoimmune epididymo-orchitis are associated with metabolic dysfunction in offspring.

Infection and inflammation of the genital tract are major potentially treatable factors contributing to male infertility. The profile of small non-coding RNA (sncRNAs) in spermatozoa can be altered by environmental exposures and inflammatory conditions. Experimental autoimmune epididymo-orchitis (EAEO) is a well-established model of autoimmune-induced chronic testicular and epididymal inflammation. This model investigates the effect of chronic inflammation on sperm sncRNA profiles and offspring phenotypes. Regarding the EAEO model, mice were immunized with testis homogenates thrice. Subsequently, flow cytometry and histological analyses were conducted on EAEO mice. Next-generation sequencing was used to profile small RNA of spermatozoa from the caput, corpus, and cauda epididymis. We performed a comprehensive integrative analysis of sperm sncRNAs and chronic epididymitis and identified their molecular signatures. The metabolic functions of the first-generation (F1) offspring were evaluated using a glucose tolerance test (GTT). Body weight and metabolic function were significantly altered in F1 offspring from EAEO sperm donors. The analysis of cauda sperm sncRNA profiles revealed that the proportions of miRNAs and tsRNAs increased and decreased, respectively, after autoimmunization. Three differentially expressed miRNAs and seven differentially expressed tsRNAs were significantly correlated with F1 metabolic dysfunction. The expression patterns of miRNAs and tsRNAs in mice partially overlapped with those observed in the spermatozoa from human patients with chronic epididymitis. We revealed that autoimmune epididymo-orchitis alters sncRNA profiles in mouse spermatozoa. Offspring from mice with autoimmune orchitis develop metabolic disorders. A comprehensive analysis of human and mouse inflammation data revealed an association between alterations in the miRNA and tsRNA profiles of epididymal spermatozoa and offspring phenotypes.

Regulatory T cells play a crucial role in maintaining sperm tolerance and male fertility

Regulatory T cells (Tregs) modulate tissue homeostatic processes and immune responses. Understanding tissue-Treg biology will contribute to developing precision-targeting treatment strategies. Here, we show that Tregs maintain the tolerogenic state of the testis and epididymis, where sperm are produced and mature. We found that Treg depletion induces severe autoimmune orchitis and epididymitis, manifested by an exacerbated immune cell infiltration [CD4 T cells, monocytes, and mononuclear phagocytes (MPs)] and the development of antisperm antibodies (ASA). In Treg-depleted mice, MPs increased projections toward the epididymal lumen as well as invading the lumen. ASA-bound sperm enhance sperm agglutination and might facilitate sperm phagocytosis. Tolerance breakdown impaired epididymal epithelial function and altered extracellular vesicle cargo, both of which play crucial roles in the acquisition of sperm fertilizing ability and subsequent embryo development. The affected mice had reduced sperm number and motility and severe fertility defects. Deciphering these immunoregulatory mechanisms may help to design new strategies to treat male infertility, as well as to identify potential targets for immunocontraception.

Interleukin-17A knockout or self-recovery alleviated autoimmune reaction induced by fluoride in mouse testis

Fluoride (F) is usually treated as a hazardous material, and F-caused public health problem has attracted global attention. Previous studies demonstrate that interleukin-17A (IL-17A) plays a crucial role in F-elicited autoimmune orchitis and self-recovery reverses F-induced testicular toxicity to some extent, but these basic mechanisms remain unclear. Thus, we established a 180 d F exposure model of wild type (WT) mice and IL-17A knockout mice (C57BL/6 J background), and 60 d & 120 d self-recovery model based on F exposure model of WT mice, and used various techniques like qRT-PCR, western blot, immunohistochemistry and ELISA to further explore the mechanism of F-induced autoimmune reaction, the role of IL-17A in it and the reversibility of F-caused toxicity in testis. The results indicated that F exposure for 180 d caused the decreased sperm quality, the damaged testis histopathology, the enhanced mRNA and protein expression levels of inflammatory cytokines, the changes of autoantibody such as the appearance and increased content of anti-testicular autoantibodies in sera and the autoantibody deposition in testis, the alterations of autoimmune related genes containing the decreased mRNA and protein expressions of AIRE and FOXP3 with an increase of MHCII, and the reduced protein expressions of CTLA4, and the activation of IL-17A signaling cascade like the elevated mRNA and protein expressions of IL-17A, Act1, NF-κB, AP-1 and CEBPβ, and the increased protein expressions of IL-17RC, with a decrease of IκBα. After IL-17A knockout, 29 of 35 F-induced changes were alleviated. In two self-recovery models, all F-caused differences except fluorine concentration in femur were gradually restored in a time-dependent manner. This study concluded that IL-17A knockout or self-recovery attenuated F-induced testicular injury and decrease of sperm quality through alleviating autoimmune reaction which was involved with the activation of IL-17A pathway, the damage of self-tolerance and the enhancement of antigen presentation.

Unraveling the effect of the inflammatory microenvironment in spermatogenesis progression.

Experimental autoimmune orchitis (EAO) is a chronic inflammatory disorder that causes progressive spermatogenic impairment. EAO is characterized by high intratesticular levels of nitric oxide (NO) and tumor necrosis factor alpha (TNFα) causing germ cell apoptosis and Sertoli cell dysfunction. However, the impact of this inflammatory milieu on the spermatogenic wave is unknown. Therefore, we studied the effect of inflammation on spermatogonia and preleptotene spermatocyte cell cycle progression in an EAO context and through the intratesticular DETA-NO and TNFα injection in the normal rat testes. In EAO, premeiotic germ cell proliferation is limited as a consequence of the undifferentiated spermatogonia (CD9+) cell cycle arrest in G2/M and the reduced number of differentiated spermatogonia (c-kit+) and preleptotene spermatocytes that enter in the meiotic S-phase. Although inflammation disrupts spermatogenesis in EAO, it is maintained in some seminiferous tubules at XIV and VII-VIII stages of the epithelial cell cycle, thereby guaranteeing sperm production. We found that DETA-NO (2mM) injected in normal testes arrests spermatogonia and preleptotene spermatocyte cell cycle; this effect reduces the number of proliferative spermatogonia and the number of preleptotene spermatocytes in meiosis S-phase (36h after). The temporal inhibition of spermatogonia clonal amplification delayed progression of the spermatogenic wave (5days after) finally altering spermatogenesis. TNFα (0.5 and 1µg) exposure did not affect premeiotic germ cell cycle or spermatogenic wave. Our results show that in EAO the inflammatory microenvironment altered spermatogenesis kinetics through premeiotic germ cell cycle arrest and that NO is a sufficient factor contributing to this phenomenon.

Activin A and CCR2 regulate macrophage function in testicular fibrosis caused by experimental autoimmune orchitis

Experimental autoimmune-orchitis (EAO), a rodent model of chronic testicular inflammation and fibrosis, replicates pathogenic changes seen in some cases of human spermatogenic disturbances. During EAO, increased levels of pro-inflammatory and pro-fibrotic mediators such as TNF, CCL2, and activin A are accompanied by infiltration of leukocytes into the testicular parenchyma. Activin A levels correlate with EAO severity, while elevated CCL2 acting through its receptor CCR2 mediates leukocyte trafficking and recruits macrophages. CCR2 + CXCR4 + macrophages producing extracellular matrix proteins contribute widely to fibrogenesis. Furthermore, testicular macrophages (TMs) play a critical role in organ homeostasis. Therefore, we aimed to investigate the role of the activin A/CCL2-CCR2/macrophage axis in the development of testicular fibrosis. Following EAO induction, we observed lower levels of organ damage, collagen deposition, and leukocyte infiltration (including fibronectin+, collagen I+ and CXCR4+ TMs) in Ccr2−/− mice than in WT mice. Furthermore, levels of Il-10, Ccl2, and the activin A subunit Inhba mRNAs were lower in Ccr2−/− EAO testes. Notably, fibronectin+ TMs were also present in biopsies from patients with impaired spermatogenesis and fibrotic alterations. Overexpression of the activin A antagonist follistatin reduced tissue damage and collagen I+ TM accumulation in WT EAO testes, while treating macrophages with activin A in vitro increased the expression of Ccr2, Fn1, Cxcr4, and Mmp2 and enhanced migration along a CCL2 gradient; these effects were abolished by follistatin. Taken together, our data indicate that CCR2 and activin A promote fibrosis during testicular inflammation by regulating macrophage function. Inhibition of CCR2 or activin A protects against damage progression, offering a promising avenue for therapeutic intervention.

Symposium 1-3 - Study for the male immunocontraception of wild animals using sperm antigens.

Testicular immune tolerance is essential for establishment of spermatogenesis, because germ cells have antigenicity. Once the tolerogenic conditions are disturbed by any factors, activated immune cells begin to attack the spermatogenic cells. Previously, we investigated early regression of spermatogenesis in the pig. The males showed aspermia due to prevalence of autoimmune orchitis, but their libido was normal. This suggested that induced autoimmune orchitis might be preferable to immunocontraception with GnRH, which eliminates both spermatogenesis and libido through abolition of testicular endocrine function. Based on this idea, we investigated the concept of immunocontraception using sperm antigens and obtained the following results. Autoimmune orchitis was induced in rats by injection of sperm emulsified with adjuvant. Although the males successfully copulated with females, the number of resulting fetuses was reduced. The condition was also similarly induced in goats. We found that lipopolysaccharide was effective for activating the immune reaction in rats. This type of orchitis is related to cellular immunity. In order to identify the highly antigenic sperm-derived molecules involved, we developed a culture system for rat T lymphocytes that could be activated using sperm antigens. The cells became highly proliferative after culture, and flow cytometry showed that they were CD4 + and TNFα + . However, transfer of the cells did not induce autoimmune orchitis in recipient rats.

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.

Evidence of pyroptosis and ferroptosis extensively involved in autoimmune diseases at the single-cell transcriptome level

BackgroundApproximately 8–9% of the world’s population is affected by autoimmune diseases, and yet the mechanism of autoimmunity trigger is largely understudied. Two unique cell death modalities, ferroptosis and pyroptosis, provide a new perspective on the mechanisms leading to autoimmune diseases, and development of new treatment strategies.MethodsUsing scRNA-seq datasets, the aberrant trend of ferroptosis and pyroptosis-related genes were analyzed in several representative autoimmune diseases (psoriasis, atopic dermatitis, vitiligo, multiple sclerosis, systemic sclerosis-associated interstitial lung disease, Crohn’s disease, and experimental autoimmune orchitis). Cell line models were also assessed using bulk RNA-seq and qPCR.ResultsA substantial difference was observed between normal and autoimmune disease samples involving ferroptosis and pyroptosis. In the present study, ferroptosis and pyroptosis showed an imbalance in different keratinocyte lineages of psoriatic skinin addition to a unique pyroptosis-sensitive keratinocyte subset in atopic dermatitis (AD) skin. The results also revealed that pyroptosis and ferroptosis are involved in epidermal melanocyte destruction in vitiligo. Aberrant ferroptosis has been detected in multiple sclerosis, systemic sclerosis-associated interstitial lung disease, Crohn’s disease, and autoimmune orchitis. Cell line models adopted in the study also identified pro-inflammatory factors that can drive changes in ferroptosis and pyroptosis.ConclusionThese results provide a unique perspective on the involvement of ferroptosis and pyroptosis in the pathological process of autoimmune diseases at the scRNA-seq level. IFN-γ is a critical inducer of pyroptosis sensitivity, and has been identified in two cell line models.

Male reproductive system alterations by SARS-CoV-2 and its pathophysiology: A review

This integrative literature review aimed to analyze the findings about the SARS-CoV-2 action on the male genital tract. The database used in the search was PubMed, Scielo and Google Scholar with the following descriptors: “Male fertility”, “COVID-19”, “Infertility”, in addition to the use of the Boolean operator (AND). The final sample was 25 baseline studies. The entry of the coronavirus takes place through the interaction of its proteins with ACE-2 and TMPRSS2. Such proteins were identified in the male reproductive system, which explains several clinical findings in patients who were infected. This interaction of the virus with cells prevents the formation of Ang 1-7, which has anti-inflammatory properties, so its reduction would cause local tissue damage in the testicular tissue. Such findings ranged from histological changes with the formation of an inflammatory infiltrate to possible autoimmune orchitis. In addition, there are controversies on certain topics, such as the carriage of the virus in semen and its potential to cause embryological damage. The study showed the different pathophysiological possibilities of the virus in causing changes in male fertility, through the inflammatory effect, direct cytopathological action of the virus, fever, infections of other structures of the reproductive system, direct alterations in the hypothalamic pituitary axis and use of drugs as a treatment. All these results show the complexity of this virus in other systems and its mechanisms, which requires further studies for its full understanding.

Exposed and Sequestered Antigens in Testes and Their Protection by Regulatory T Cell-Dependent Systemic Tolerance.

Continuous exposure of tissue antigen (Ag) to the autoantigen-specific regulatory T cells (Treg) is required to maintain Treg-dependent systemic tolerance. Thus, testis autoantigens, previously considered as sequestered, may not be protected by systemic tolerance. We now document that the complete testis antigen sequestration is not valid. The haploid sperm Ag lactate dehydrogenase 3 (LDH3) is continuously exposed and not sequestered. It enters the residual body (RB) to egress from the seminiferous tubules and interact with circulating antibody (Ab). Some LDH3 also remains inside the sperm cytoplasmic droplets (CD). Treg-depletion in the DEREG mice that express diphtheria toxin receptor on the Foxp3 promoter results in spontaneous experimental autoimmune orchitis (EAO) and Ab to LDH3. Unlike the wild-type male mice, mice deficient in LDH3 (wild-type female or LDH3 NULL males) respond vigorously to LDH3 immunization. However, partial Treg depletion elevated the wild-type male LDH3 responses to the level of normal females. In contrast to LDH3, zonadhesin (ZAN) in the sperm acrosome displays properties of a sequestered Ag. However, when ZAN and other sperm Ag are exposed by vasectomy, they rapidly induce testis Ag-specific tolerance, which is terminated by partial Treg-depletion, leading to bilateral EAO and ZAN Ab response. We conclude that some testis/sperm Ag are normally exposed because of the unique testicular anatomy and physiology. The exposed Ag: 1) maintain normal Treg-dependent systemic tolerance, and 2) are pathogenic and serve as target Ag to initiate EAO. Unexpectedly, the sequestered Ags, normally non-tolerogenic, can orchestrate de novo Treg-dependent, systemic tolerance when exposed in vasectomy.

Immune cell characterization in spontaneous autoimmune orchitis in dogs

With a prevalence of up to 35% in dogs with reproductive problems, azoospermia is one of the most important reasons for male infertility. Non-obstructive azoospermia, without clinical symptoms, but histopathological damage of the testicular tissue and immune cell infiltration is referred to as spontaneous autoimmune orchitis (AIO) in the literature. Published cases in dogs describe immune cell infiltration; however, there is no consent about the involved immune cell types. We aimed to characterize immune cells in testicular biopsies of dogs with AIO (n = 9) and to compare them to those in testicular specimens from healthy control dogs with normospermic ejaculates (CG; n = 5). Immunohistochemistry was performed using specific antibodies against CD3, PAX5, MAC387, IgG and IgM to proof the presence of T lymphocytes, B lymphocytes, macrophages and early and late plasma cells, respectively. Presence of immune cells in healthy testicular tissue was low and restricted to T lymphocytes and macrophages in the interstitium with the latter also being found within the blood vessels. Different to this, AIO samples revealed presence of all investigated immune cells, underlining lymphoplasmacytic nature of chronic asymptomatic immune-mediated orchitis. Canine spontaneous AIO is characterised by a significantly increased number of immune cells, namely ≥33 immune cells/mm2 (sensitivity/specificity: 100% based on our data). The pathogenesis of canine AIO is hypothesized to be as follows: 1. Macrophages initiate AIO via T lymphocyte activation. 2. T lymphocytes lead to a “delayed type immunological response” and development of AIO. 3. Invaded B lymphocytes later differentiating to plasma cells are responsible for the second humoral immunological response and cause progression of AIO. Different to the situation in CG, T lymphocytes and plasma cells were identified within the seminiferous tubules indicating that disruption of spermatogenesis in AIO might be related to invading immune cells. Testicular biopsies provide an essential tool in the diagnosis of spontaneous AIO.

GIT1 is an untolerized autoantigen involved in immunologic disturbance of spermatogenesis.

Male haploid cells, spermatids and spermatozoa, that appear after the establishment of immune tolerance express novel cell surface and intracellular proteins that can be recognized as foreign antigens by the self-immune system. However, these germ cells do not normally evoke a pathological immune response. The immune-privileged micro-circumstance in testis involving the blood-testis-barrier formed by Sertoli cells protects these germ cells from autoimmune attack. We recently found that immunization with heat shock protein family A member 4-like (HSPA4L), one of the new differentiation antigens of haploid cells, induced experimental autoimmune orchitis (EAO) in A/J male mice. In this study, we focused on G protein-coupled receptor kinase interacting protein-1 (GIT1), another haploid cell-specific differentiation antigen, to investigate whether GIT1 is a target autoantigen for EAO induction. GIT1 emulsified with complete Freund's adjuvant was injected subcutaneously into the mice inguinal region once on day 0 and again on day 14, and the optimum condition of EAO induction was determined. Mice immunized with 200μg GIT1 showed significantly higher incidence of EAO than that of immunization with other concentrations. In particular, significant lymphocytic inflammation and extensive aspermatogenesis were observed in these mice at 120days after the first immunization. These findings indicate that GIT1 is also a target antigen that induces EAO, like HSPA4L.

High Throughput scRNA-Seq Provides Insights Into Leydig Cell Senescence Induced by Experimental Autoimmune Orchitis: A Prominent Role of Interstitial Fibrosis and Complement Activation.

Leydig cells (Lc), located in the interstitial space of the testis between seminiferous tubules, produce 95% of testosterone in male individuals, which is pivotal for male sexual differentiation, spermatogenesis, and maintenance of the male secondary sex characteristics. Lc are prone to senescence in aging testes, resulting in compromised androgen synthesis capability upon aging. However, little is known about whether Lc undergo senescence in a chronic inflammatory environment. To investigate this question, mouse models of experimental autoimmune orchitis (EAO) were used, and Lc were analyzed by high throughput scRNA-Seq. Data were screened and analyzed by correlating signaling pathways with senescence, apoptosis, androgen synthesis, and cytokine/chemokine signaling pathways. EAO did induce Lc senescence, and Lc senescence in turn antagonized androgen synthesis. Based on the correlation screening of pathways inducing Lc senescence, a plethora of pathways were found to play potential roles in triggering Lc senescence during EAO, among which the Arf6 and angiopoietin receptor pathways were highly correlated with senescence signature. Notably, complement and interstitial fibrosis activated by EAO worsened Lc senescence and strongly antagonized androgen synthesis. Furthermore, most proinflammatory cytokines enhanced both senescence and apoptosis in Lc and spermatogonia (Sg) during EAO, and proinflammatory cytokine antagonism of the glutathione metabolism pathway may be key in inducing cellular senescence during EAO.

Isolated Autoimmune Orchitis Due to IgG4 Hypersecretion Presenting as Tumor-Like Mass: Case Report and Review of Literature

Background: IgG4-related disease is a rare autoimmune condition that presents with lymphoplasmacytic infiltrate and fibrosis in the organ affected. Isolated testicle involvement is uncommon and there are only a few cases reported in the literature. Case Presentation: We report a case of isolated chronic orchitis due to IgG4 hypersecretion in a 61-year-old patient that evolved with asymptomatic tumor-like mass growth and was treated with left orchiectomy. Histopathological study revealed orchitis related to IgG4 hypersecretion disease. Conclusion: IgG4-related disease can be manifested as a multi or single-organ disorder. Most diagnoses are made after surgery with histopathological analysis. Most of the cases in literature stand out the difficulty in diagnosis and necessity of high suspicion due to this condition’s similarity with neoplasm presentation.

Experimental autoimmune orchitis induced by immunization with GIT1 in mice

Experimental autoimmune orchitis induced by immunization with GIT1 in mice

CDC1 Dependent Accumulation of Memory T Cells Is Required for Chronic Autoimmune Inflammation in Murine Testis.

As an immune privilege site, there are various types of immune cells in the testis. Previous research has been focused on the testicular macrophages, and much less is known about the T cells in the testis. Here, we found that T cells with memory phenotypes were the most abundant leukocyte in the testis except for macrophages. Our results showed that the proportion of testicular T cells increases gradually from birth to adulthood in mice and that the primary type of T cells changed from γδTCR+ T cells to αβTCR+ T cells. In addition, under homeostatic conditions, CD8+ T cells are the dominant subgroup and have different phenotypic characteristics from CD4+ T cells. We found that cDC1, but not cDC2, is necessary for the presence of T cells in the testis under physiological state. A significant decrease of T cells does not have a deleterious effect on the development of the testis or spermatogenesis. However, cDC1-dependent T cells play an indispensable role in chronic autoimmune orchitis of the testis. Collectively, our multifaceted data provide a comprehensive picture of the accumulation, localization, and function of testicular T cells.

Heat shock protein A4L is a potent autoantigen for testicular autoimmunity in mice

Experimental autoimmune orchitis (EAO) may be used as a model to investigate immunological infertility in men. Murine EAO is induced via immunization with auto-immunogenic antigens (AIAgs) from testicular germ cells (TGCs). CD4 + T cells play a crucial role in EAO induction. However, whether AIAgs induce an immune response remains unclear. We aimed to identify self-antigens that induce EAO by screening a phage display library of random TGC peptides using IgG from EAO-induced A/J mice. Twenty TGC-specific AIAgs were detected, and G protein-coupled receptor kinase 2 interacting protein-1 (GIT1) and heat shock protein A4L (HSPA4L) were identified as candidate AIAgs that induce EAO. Immunization with GIT1 or HSPA4L, emulsified in complete Freund’s adjuvant, resulted in 66 % or 100 % incidence of EAO, respectively, indicating that HSPA4L is a most potent AIAg that induces EAO in mice. These findings may expectedly help improve the diagnostic procedures and treatment of immunological infertility in men.

Autoimmune experimental orchitis and chronic glomerulonephritis with end stage renal disease are controlled by Cgnz1 for susceptibility to end organ damage

Cgnz1 on chromosome 1 mapped into a 1.34 Mb region of chromosome 1 in NZM2328 confers the progression of immune complex (IC)-mediated glomerulonephritis (GN) from acute GN (aGN) to chronic GN (cGN) with severe proteinuria and end stage renal disease in female mice. This genetic locus mediates podocyte susceptibility to IC-mediated damage. Taking advantage of the published observation that Cgnz1 is derived from NZW and that NZW is susceptible to orchitis, epididymitis and vasitis while C57L/J is resistant to these diseases, the possibility that this genetic region also confers germ cells susceptible to damage with aspermatogenesis and sterility in an active experimental autoimmune orchitis (EAO) model was investigated. Male mice from multiple intrachromosome (chromosome 1) recombinant strains were subjected to immunization with a sperm homogenate in CFA with concomitant administration of Bordetella pertussis toxin. There was concordance of the progression from aGN to cGN, severe proteinuria and end stage renal disease with susceptibility of EAO in NZM2328 and its congenic strains with various chromosome 1 genetic intervals introgressed from C57L/J to NZM2328. Both resistant and susceptible strains made comparable anti-testis and anti-sperm Abs. Thus the genetic interval that determines susceptibility to EAO is identical to that of Cgnz1 and mapped to the 1.34 Mb region in chromosone 1. This region likely confers germ cells in the male gonad susceptible to damage by immunologically mediated inflammation. This region has been tentatively renamed Cgnz1/Eaoz1. These observations further emphasize the importance of end organ susceptibility to damage in the pathogenesis of both systemic and organ specific autoimmune diseases.