Organ-specific autoimmune diseases induced in mice by elimination of T cell subset. I. Evidence for the active participation of T cells in natural self-tolerance; deficit of a T cell subset as a possible cause of autoimmune disease

Organ-specific autoimmune diseases such as oophoritis, gastritis, thyroiditis, and orchitis were induced in female or male nude (nu/nu) mice by the transfer of nu/+spleen cells from which particular Lyt T cell subset(s) had been removed: nu/+spleen cells treated with anti-Lyt-1 plus complement (C) caused disease in recipient nude mice; anti-Lyt-2 plus C-treated spleen cells, in contrast, did not. The cells responsible for disease induction are believed to be Thy-1+, Lyt-1-, 2,3- (Thy-1, Lyt-1, 2,3), since spleen cells treated with mixed antisera, including anti-Lyt-1 and anti-Lyt-2, plus C, could induce the disease with almost the same incidence as anti-Lyt-1 plus C-treated cells (oophoritis 50%, gastritis 25%, thyroiditis 10-20%, and orchitis 40%). Cells treated with mixed antisera of anti-Thy-1, anti-Lyt-1, and anti-Lyt-2, plus C, could not induce autoimmune disease. Each induced autoimmune disease could be adoptively transferred to other nude mice via spleen cells, with resulting histological lesion of corresponding organs and development of specific circulating autoantibodies. Since anti-Thy-1 plus C treatment of donor spleen cells abrogated the capacity to transfer the disease, we conclude that T cells are required as effector cells, and that these may develop from Lyt-1-, 2,3- cells. Lyt-1+, 2,3- cells were demonstrated to have suppressive activity upon the development of the diseases; induction of autoimmunity was completely inhibited by the cotransfer of Lyt-1+, 2,3- cells with Lyt-1-, 2,3- cells. When anti-Lyt-2 plus C-treated cells (i.e., Lyt-1+, 2,3- and Lyt-1-, 2,3- cells) were mixed with anti-Lyt-1 and anti-Lyt-2 plus C-treated cells (i.e., Lyt-1-, 2,3- cells) in various ratios, then transferred to nude mice, the development of each autoimmune disease was clearly inhibited, even by small doses of Lyt-1+, 2,3- cells. The autoimmune disease we were able to induce was quite similar to human organ-specific autoimmune disease in terms of the spectrum of organs involved, histopathological features, and the development of autoantibodies to corresponding organ components (oocytes, parietal cells, thyroid colloid, including thyroglobulin, and sperm).(ABSTRACT TRUNCATED AT 400 WORDS)

Orchitis: a complication of severe acute respiratory syndrome (SARS)

Severe acute respiratory syndrome (SARS) coronavirus has been known to damage multiple organs; however, little is known about its impact on the reproductive system. In the present study, we analyzed the pathological changes of testes from six patients who died of SARS. Results suggested that SARS caused orchitis. All SARS testes displayed widespread germ cell destruction, few or no spermatozoon in the seminiferous tubule, thickened basement membrane, and leukocyte infiltration. The numbers of CD3+ T lymphocytes and CD68+ macrophages increased significantly in the interstitial tissue compared with the control group (P < 0.05). SARS viral genomic sequences were not detected in the testes by in situ hybridization. Immunohistochemistry demonstrated abundant IgG precipitation in the seminiferous epithelium of SARS testes, indicating possible immune response as the cause for the damage. Our findings indicated that orchitis is a complication of SARS. It further suggests that the reproductive functions should be followed and evaluated in recovered male SARS patients.

Infectious, inflammatory and 'autoimmune' male factor infertility: how do rodent models inform clinical practice?

BACKGROUND

Infection and inflammation of the reproductive tract are significant causes of male factor infertility. Ascending infections caused by sexually transmitted bacteria or urinary tract pathogens represent the most frequent aetiology of epididymo-orchitis, but viral, haematogenous dissemination is also a contributory factor. Limitations in adequate diagnosis and therapy reflect an obvious need for further understanding of human epididymal and testicular immunopathologies and their contribution to infertility. A major obstacle for advancing our knowledge is the limited access to suitable tissue samples. Similarly, the key events in the inflammatory or autoimmune pathologies affecting human male fertility are poorly amenable to close examination. Moreover, the disease processes generally have occurred long before the patient attends the clinic for fertility assessment. In this regard, data obtained from experimental animal models and respective comparative analyses have shown promise to overcome these restrictions in humans.

OBJECTIVE AND RATIONALE

This narrative review will focus on male fertility disturbances caused by infection and inflammation, and the usefulness of the most frequently applied animal models to study these conditions.

SEARCH METHODS

An extensive search in Medline database was performed without restrictions until January 2018 using the following search terms: 'infection' and/or 'inflammation' and 'testis' and/or 'epididymis', 'infection' and/or 'inflammation' and 'male genital tract', 'male infertility', 'orchitis', 'epididymitis', 'experimental autoimmune' and 'orchitis' or 'epididymitis' or 'epididymo-orchitis', antisperm antibodies', 'vasectomy'. In addition to that, reference lists of primary and review articles were reviewed for additional publications independently by each author. Selected articles were verified by each two separate authors and discrepancies discussed within the team.

OUTCOMES

There is clear evidence that models mimicking testicular and/or epididymal inflammation and infection have been instructive in a better understanding of the mechanisms of disease initiation and progression. In this regard, rodent models of acute bacterial epididymitis best reflect the clinical situation in terms of mimicking the infection pathway, pathogens selected and the damage, such as fibrotic transformation, observed. Similarly, animal models of acute testicular and epididymal inflammation using lipopolysaccharides show impairment of reproduction, endocrine function and histological tissue architecture, also seen in men. Autoimmune responses can be studied in models of experimental autoimmune orchitis (EAO) and vasectomy. In particular, the early stages of EAO development showing inflammatory responses in the form of peritubular lymphocytic infiltrates, thickening of the lamina propria of affected tubules, production of autoantibodies against testicular antigens or secretion of pro-inflammatory mediators, replicate observations in testicular sperm extraction samples of patients with 'mixed atrophy' of spermatogenesis. Vasectomy, in the form of sperm antibodies and chronic inflammation, can also be studied in animal models, providing valuable insights into the human response.

WIDER IMPLICATIONS

This is the first comprehensive review of rodent models of both infectious and autoimmune disease of testis/epididymis, and their clinical implications, i.e. their importance in understanding male infertility related to infectious and non-infectious/autoimmune disease of the reproductive organs.

In vivo dynamic MRI tracking of rat T-cells labeled with superparamagnetic iron-oxide particles

Dynamic MRI tracking of rat T-cells in vivo is performed in rat testicles after labeling isolated rat T-cells in vitro with superparamagnetic dextran-coated iron-oxide particles, BMS180549. Tissue inflammation induced by the local injection of the calcium ionophore, A23187, is used to attract labeled T-cells. Gradient-echo MR images of rat testicles show a statistically significant decrease (4%) of the signal intensity in areas of injection of A23187 as early as 30 min after intravenous infusion of 2 x 10(8) labeled T-cells. The signal change reaches its maximum (6-7% decrease) at about 60-120 min after cell infusion. T2-mapping also shows a decrease of T2 in the areas with A23187. Image quantitation, which includes a chemical-shift effect, significantly enhances the sensitivity for detection of superparamagnetically labeled T-cells. Localization of labeled T-cells in rat testicles has been verified by fluorescence microscopy studies of T-cells co-labeled with a lipophilic fluorescent carbocyanine dye, 1,1-dioctadecyl-3,3,3',3'-tetramethyl-lindocarbocyanine perchlorate. These results represent the first successful demonstration of dynamic tracking of specific cells in vivo using MRI.

High-resolution ultrasonography of scrotal pathology

A prototype high-resolution (10-MHz) real-time ultrasonic system was used to study 22 patients who were ultimately proved to have intra- and extratesticular tumors, scrotal fluid collections, and inflammatory processes. In 5 of 6 patients with primary testicular masses, there were areas of decreased echogenicity within the testis when compared with surrounding normal tissue. In general, the method was highly effective in differentiating and characterizing testicular and extratesticular processes.

Interleukin-6 and IL-6 receptor cell expression in testis of rats with autoimmune orchitis

Experimental autoimmune orchitis (EAO) is an organ-specific model of autoimmunity characterized by an interstitial lymphomononuclear cell infiltrate as well as sloughing and apoptosis of germ cells. EAO was induced in adult male Sprague-Dawley rats by active immunization with testicular homogenate and adjuvants. Rats injected with saline solution and adjuvants were used as control group. The aim of this work was to study the expression of interleukin-6 (IL-6) and its receptor (IL-6R) in the testis of rats with EAO and analyze whether IL-6 could be involved in germ cell apoptosis. By immunohistochemistry, we detected IL-6 expression in testicular macrophages and Leydig cells of control and EAO rats. Sertoli cells showed IL-6 immunoreactivity in most of the seminiferous tubules of control rats, while a few IL-6+ Sertoli cells were found in the testis of rats with EAO. IL-6R immunoreactivity was observed in macrophages, Leydig and germ cells. A significant increase was noted in the number of IL-6R+ germ cells in rats with EAO compared to control rats. The content of IL-6 (ELISA) in the conditioned media obtained from testicular macrophages of rats with orchitis was significantly higher than in the control group. By immunofluorescence performed on isolated testicular macrophages, IL-6 was shown to be expressed by monocytes recently arrived from circulation (ED1+ cells), while resident macrophages (ED2+ cells) were negative. In vitro experiments (trypan blue and MTS assays) showed that IL-6 (50 ng/ml) reduced germ cell viability. We demonstrated also using the TUNEL technique that IL-6 added to cultures of seminiferous tubule segments induced apoptosis of germ cells. Our results suggest that IL-6 and IL-6R may be involved in the pathogenesis of autoimmune orchitis by promoting testicular inflammation and germ cell apoptosis.

Adoptive transfer of murine autoimmune orchitis to naive recipients with immune lymphocytes

A protocol was developed for reproducibly transferring experimental autoimmune orchitis (EAO) to naive recipient mice. Cell donors were (C57BL/6 x A/J)F1 mice immunized about 14 days earlier with mouse testicular homogenate with Freund's adjuvant and an extract of Bordetella pertussis. Lymphocytes from lymph nodes and spleens were equally capable of transferring disease. As few as 5 X 10(6) cells were able to transfer EAO, which began on Day 5-7 after transfer. Infiltrate of lymphocytes and macrophages in the region of the rete testis and straight tubules was the most reproducible early lesion, suggesting that this is the initial site of T cell-antigen interaction. It was not necessary to use both Mycobacteria and B. pertussis adjuvants in donor immunization to achieve transfer of EAO. Disease transfer was antigen specific since only cells from donors immunized with TH could transfer disease. In vitro stimulation of the cells with testicular antigens and/or concanavalin A was a prerequisite to successful transfer of EAO, which was dependent on the presence of L3T4+ T cells since depletion of these cells greatly diminished EAO in recipients and the lymphocyte proliferation response to testicular antigens. Disease did not depend on an antibody response by the recipients. The results imply that effector cells, once generated by immunization and fully activated or selected by in vitro stimulation, can home to specific locations in the testis, locate relevant autoantigens, and cause disease.

Involvement of tumor necrosis factor-alpha in the pathogenesis of autoimmune orchitis in rats

We studied the testicular macrophages of rats with experimental autoimmune orchitis (EAO) and analyzed whether the tumor necrosis factor-alpha (TNFalpha) is involved in germ cell apoptosis and in Leydig cell steroidogenesis. The EAO was induced in adult male Sprague-Dawley rats by active immunization with testicular homogenate and adjuvants. In the experimental group, a severe orchitis was observed 80 days after the first immunization. ED1- and ED2-positive macrophages were quantified by immunohistochemistry. The TNFalpha concentration of conditioned media from testicular macrophages (TMCM) was determined by ELISA. The number of apoptotic TNF receptor 1 (TNFR1)-positive germ cells was identified by combining in situ end labeling of apoptotic DNA and immunohistochemical techniques. The effect of TNFalpha on Leydig cell testosterone production was determined by RIA. In rats with EAO, we observed a significant increase in the number of TNFalpha-positive testicular macrophages, the TNFalpha concentration in TMCM, and the number of TNFR1-positive germ cells. Sixty percent of TNFR1-positive germ cells were apoptotic. These results suggest that TNFalpha could be involved in the pathogenesis of EAO. Acting together with other local factors such as Fas-FasL, TNFalpha could trigger germ cell apoptosis. We also demonstrated that TNFalpha inhibited in vitro testosterone production in basal and hCG-stimulated Leydig cells from rats with orchitis.

Identification of immunodominant autoantigens in rat autoimmune orchitis

Infection and inflammation of the genital tract are amongst the leading causes of male infertility. Experimental autoimmune orchitis (EAO) in the rat serves as a model for the investigation of inflammatory testicular impairment. In this study, experiments were conducted to identify the molecules that are responsible for eliciting the autoimmune attack on the testis. EAO was induced in in-bred Wistar rats by active immunization with testis homogenates (EAO group I). Development of disease was observed using histological techniques and a new non-invasive three-dimensional (3D) imaging technology for in vivo monitoring, termed flat-panel volumetric computed tomography (fpvCT). Examination of control and EAO testes demonstrated the superior image quality of high-resolution fpvCT. A proteomics approach using 2D SDS-PAGE and immunoblotting analysis with EAO sera identified 12 spots. Seven were subsequently identified by mass spectrometry as heat shock proteins 60 (Hsp60) and 70 (Hsp70), disulphide isomerase ER-60, alpha-1-anti-trypsin, heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1), sperm outer dense fibre major protein 2 (ODF-2), and phosphoglycerate kinase 1. Hsp70, ODF-2, hnRNP H1, and ER-60 were identified by all EAO sera studied. To test the capacity of the identified proteins to elicit testicular autoimmune disease, recombinant proteins were used either individually or in combination to immunize rats (EAO group II). In all groups, the incidence of EAO was 25%. Inflammatory-type (ED1+) and resident (ED2+) macrophages, lymphocytes (CD45RA+), and dendritic cells (Ox-62+) were strongly increased in EAO group II animals, comparable to the testes of EAO I rats. Pre-immunization with a low dose of recombinant Hsp 70, hnRNP H1 or ODF-2 before induction of EAO with testis homogenate significantly delayed the onset of EAO but could not prevent disease. The identification of testicular autoantigens will allow a better understanding of disease pathogenesis and could provide a basis for the development of novel therapies for inflammation-based male infertility.

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.

Sequential study of the histopathology and cellular and humoral immune response during the development of an autoimmune orchitis in Wistar rats

Wistar rats immunized with an homologous testicular homogenate (TH) and complete Freund's adjuvant, followed by i.v. injection of Bordetella pertussis, developed an autoimmune orchitis (EAO). Animals were studied at 7, 16, 30, 50, and 80 days (d) after the first immunization. An important lesion of the testis only appeared at 50 d, increasing in severity and incidence (77%) at 80 d. Lesions were characterized by a prevalent aspermatogenesis with tubular atrophy and mild interstitial mononuclear infiltrates. Delayed-type hypersensitivity response (DTH) against TH was detected early at 7 d and, except for 16 d, it increased with time, reaching a maximum at 80 d. A good temporal relationship between DTH and histopathology was found. Circulating antibodies to TH, detected by ELISA, were only present in 64% of the animals with testis lesion, while no deposits of IgG or C3 in the seminiferous tubules were seen. We describe a sequence of immunological events, concomitant with pathological changes of the testis, during the development of a severe EAO in Wistar rats.

West Nile virus encephalitis with myositis and orchitis

This report documents the hospital course and autopsy findings of a 43-year-old man with a renal allograft who died of West Nile virus (WNV) encephalitis. Central nervous system (CNS) findings were those of severe necrotizing and hemorrhagic encephalitis affecting gray matter regions limited to the diencepahlon, rhombencephalon, spinal cord, and limbic system. The bilateral process exhibited preferential involvement of motor neurons. Brain imaging obtained 6 days before death demonstrated an unusual pattern of involvement corresponding with the autopsy findings, confirming that imaging may be a specific diagnostic guide in WNV encephalitis. Extra-CNS findings include myositis with T-lymphocyte infiltration of nerve fibers, suggesting that the virus may reach the CNS via peripheral nerves. Orchitis with dense T-lymphocyte infiltration and syncytial cell formation thought to be due to WNV were also noted.

Immunohistochemical characterization of seminoma and its inflammatory cell infiltrate

Monoclonal antibodies and the avidin-biotin immunoperoxidase technique were used to study the expression of major histocompatibility complex antigens and the nature of the inflammatory cell infiltrate in 10 testicular seminomas. Tumor cells did not react with anti-HLA-A,B,C, anti-HLA-DR, anti-HLA-DQ, and anti-beta 2 microglobulin antibodies to major histocompatibility antigens. All of the 10 tumors contained a slight to marked inflammatory cell infiltrate at the periphery of the tumor, in the connective tissue septa, and in the tumor lobules. The lymphocytes were predominantly T cells; B lymphocytes were rare. The tissue available for study from seven tumors showed tumor lobules separated by delicate fibrovascular septa; T lymphocytes with a cytotoxic-suppressor phenotype predominated in this area in six tumors. In the four tumors in which peripheral tissue was available for study, cells with a helper-inducer phenotype predominated at the tumor margin. Tissue from three tumors showed stromal sclerosis and a dense lymphohistiocytic infiltrate separating individual and small nests of tumor cells; T cells with a helper-inducer phenotype predominated in these cases. Aggregates of macrophages that expressed OKM-1 and Leu-M3 were present in eight of 10 tumors. These findings indicate that two types of immune reactions may be operating: a delayed-type hypersensitivity response at the periphery and a cytotoxic-suppressor effector mechanism in the tumor lobules. Furthermore, major histocompatibility complex antigens are not involved in eliciting the inflammatory response.

Mechanism of infertility in male guinea pigs immunized with sperm PH-20

PH-20, a testis-specific protein first expressed in haploid germ cells, is present on the posterior head plasma membrane and inner acrosomal membrane of mature guinea pig sperm. PH-20 is bifunctional, having a hyaluronidase activity that allows sperm to penetrate the cumulus layer and a separate activity required for binding of acrosome-reacted sperm to the zona pellucida. The immunization of male guinea pigs with PH-20 reproducibly results in infertility with a duration of 6-12 mo or longer. In this study, we analyzed the immunopathology in the reproductive tract of PH-20-immunized males to probe the mechanism(s) responsible for the induced infertility and found two separate effects. Remarkably, in almost all infertile, PH-20-immunized males, the caudae epididymides were empty (contained no sperm) or contained only abnormal sperm. The complete loss of normal sperm in the epididymis apparently results in infertility. A second effect was the induction of experimental autoimmune orchitis (EAO), representing the first report of EAO induced by a purified testis/sperm molecule of known functions. PH-20-induced EAO differed from EAO induced by crude testis antigens in two respects: 1) an absence of epididymitis with abscess and granuloma and 2) the presence of antibody on germ cells within seminiferous tubules and inside the cauda epididymidis. The former suggests that crude testis antigens other than PH-20 are responsible for epididymitis, and the latter suggests a possible role of antibody in EAO pathogenesis and infertility induction. Return to fertility, after 6-12 mo, was accompanied by regression of EAO and reappearance of spermatozoa in the caudae epididymides.

Testicular infarction secondary to acute inflammatory disease: demonstration by B-scan ultrasound

Acute epididymitis can lead to obstruction of the adjacent testicular blood supply, resulting in focal or diffuse infarction of the testis or epididymis in the absence of torsion. Four cases are presented to demonstrate the spectrum of B-scan ultrasound findings, ranging from focal necrosis of the epididymis and ischemic infarction of the testis to diffuse testicular infarction. Epididymal enlargement and skin thickening are consistently seen on ultrasound as well as swelling and decreased echogenicity of the testicle. The authors suggest a protocol for acute scrotal symptoms, incorporating clinical findings and (where appropriate) radionuclide scans.

The black mink (Mustela vison). A natural model of immunologic male infertility

Breeding for fine black fur has generated a colony of mink wherein 20-30% of the males are infertile. Two clinical groups are distinguishable: one being infertile from the start (primary infertility), and the other infertile after one or more years of fertility (secondary fertility). Although the etiology of primary infertility is unknown, the available data indicate that secondary infertility is associated with an autoimmune disease of the testis. Thus, male mink with secondary infertility have (a) higher prevalence and levels of anti-sperm antibody when compared with animals with primary infertility, and the antibody prevalence varies with fur color; (b) severe monocytic orchitis (47%) and/or aspermatogenesis (75%) with negative cultures for bacterial, fungal, mumps, or Coxsackie B viral organisms; (c) massive and extensive granular deposits of mink IgG and/or C3 (71%), typical of immune complexes, along the basal lamina of seminiferous tubules; (d) testes that when eluted with buffer or low pH yielded IgG that was 10-fold enriched in anti-sperm antibody activity as compared with serum IgG; and (e) no immunopathologic evidence of Aleutian mink disease. Although the sperm antigen-antibody complexes in the testis may be important as a pathogenetic mechanism of the testicular disease, there is no correlation between fluorescent anti-sperm antibody detection in the serum and the infertile state. The infertile black mink is a new model of infertility associated with naturally occurring autoimmune disease of the testis.

Sonographic findings in tuberculous epididymitis and epididymo-orchitis

PURPOSE

This paper presents the sonographic findings in scrotums of patients affected with tuberculous epididymitis or epididymo-orchitis.

METHODS

Eighteen patients with a total of 22 abnormal hemiscrotums (4 patients had bilateral lesions) underwent scrotal sonography. Pathologic confirmation was obtained via epididymectomy in 10 cases, epididymo-orchiectomy in 7 cases, and scrotal exploration and biopsy in 3 cases. The histopathologic diagnosis was tuberculous epididymitis in 12 cases and epididymo-orchitis in 8 cases.

RESULTS

Lesions involved the head of the epididymis in 8 cases, the tail in 5 cases, and the entire epididymis in 9 cases. The enlarged epididymis was hypoechoic in 13 cases, hyperechoic in 2 cases, and of mixed echogenicity in 7 cases. The echotexture was heterogeneous in 17 cases and homogeneous in 5 cases. Testicular involvement in 7 cases appeared as a diffusely enlarged hypoechoic testis in 2 cases, an ill-defined hypoechoic lesion in 1 case, a well-demarcated hypoechoic lesion in 2 cases, and multiple small hypoechoic nodules in an enlarged testis in 2 cases. Hydrocele, sinus tract, and extratesticular calcifications were seen in 12, 4, and 2 cases, respectively.

CONCLUSIONS

The heterogeneous and hypoechoic swelling of the epididymis or the concomitant hypoechoic lesion of the testis with associated sinus tract or extratesticular calcifications may be helpful in the diagnosis of tuberculous epididymitis or epididymo-orchitis, especially in patients with known genitourinary tuberculosis.

Monocyte chemoattractant protein-1 (MCP-1/CCL2) in experimental autoimmune orchitis

Experimental autoimmune orchitis (EAO) is characterized by an interstitial mononuclear cell infiltrate and a severe lesion of seminiferous tubules with germ cells that undergo apoptosis and sloughing. The mechanism by which immune cells migrate and extravasate in the testicular interstitium is poorly understood. The aim of this study was to detect the variations in the expression of monocyte chemoattractant protein-1 (MCP-1/CCL2) and its receptor in the testis of rats undergoing autoimmune orchitis. EAO was induced in Sprague-Dawley adult rats by active immunization with an emulsion of testicular homogenate and complete Freund adjuvant using Bordetella pertussis as co-adjuvant. Control rats injected with saline and adjuvants and normal untreated rats were also studied. By ELISA we observed a significant increase of MCP-1 in the testicular fluid (TF) and in the conditioned medium obtained from cultures of testicular macrophages of rats with EAO compared with control groups. By immunohistochemistry, an increase in MCP-1 expression was observed in mononuclear, endothelial, Leydig and peritubular cells. MCP-1 immunoreactivity was also detected in Sertoli cell cytoplasm of rats with severe orchitis. A 2-fold increase in the number of mononuclear cells that express CCR2 was also found in rats with orchitis compared with controls. In conclusion, we demonstrated in vivo that MCP-1 is highly expressed in testicular interstitial cells suggesting that this chemokine has an important role in recruiting immune cells to the testis in rats undergoing autoimmune orchitis.

Mechanisms of autoimmune disease in the testis and ovary

This article reviews recent research on autoimmune diseases of the testis and ovary based on two experimental approaches for induction of autoimmune diseases of the gonads (immunization with testis or ovary antigen, usually with adjuvant, and deliberate alteration of the immune system in normal animals, without injecting antigen or adjuvant). It has been found that the local testicular immunoregulatory environment partially impedes autoimmune responses to ontogenic testis antigens and regulatory T cells usually control pathogenic T cells that are found in the normal peripheral immune system. If the clonal balance of these CD4+ T cell subsets is tipped in favour of pathogenic T cells, autoimmune diseases of the gonads could ensue. Loss of regulatory T cells may occur through aberrant T cell development, or oophoritogenic T cells can be activated by non-ovarian peptides that crossreact with self peptides at the level of the T cell receptor. The inflammatory CD4 (Th1) T cell mechanism has been established to be a critical pathway for autoimmune orchitis and autoimmune oophoritis; tumour necrosis factor has been shown to be required for amplification of the pathogenic T cell response. Histopathology has suggested tissue locations wherein pathogenic T cells encounter testicular and ovarian target antigens. Antibodies bind to both testicular and ovarian target antigens during the development of autoimmune orchitis and autoimmune oophoritis, but the precise role of the antibodies has not been determined. Resolution of this role may influence the clarification of the mechanism whereby autoantibody may access ejaculated human spermatozoa to cause infertility and the future of contraceptive vaccine development based on ovarian antigens. A novel mechanism of autoantibody induction and an immunogenetic approach to autoimmune oophoritis and orchitis, based on molecular linkage analysis of inbred mice, are also reviewed.

Role of interferon-alpha-2B in prevention of testicular atrophy with unilateral mumps orchitis

OBJECTIVES

To determine the effectiveness of intravenously administered interferon-alpha-2B for the prevention of testicular atrophy in postpubertal men with mumps orchitis.

METHODS

Eighteen patients with mumps orchitis were evaluated. The patients were hospitalized, and 3 x 1,000,000 IU intravenous interferon-alpha-2B was administered daily for a total of 7 days. All patients were evaluated by testicular biopsy on the 12th month after interferon treatment.

RESULTS

Biopsy results demonstrated total atrophy of the seminiferous tubules in seven (38.8%), 10% atrophy in three (16.6%), and no apparent histopathologic alterations except an arrest in spermatogenesis in eight (44.6%) testes.

CONCLUSIONS

Systematic treatment with interferon-alpha-2B does not seem completely effective in preventing testicular atrophy after mumps orchitis. Further investigations involving larger populations are needed.

Identification of a dendritic cell population in normal testis and in chronically inflamed testis of rats with autoimmune orchitis

Experimental autoimmune orchitis (EAO) in the rat is the primary chronic animal model for the investigation of one of the main causes of male infertility, viz., testicular inflammation. Dendritic cells (DC) are potent antigen-presenting cells that play a fundamental role in autoimmune disease. We investigated the number of DC in normal testis and examined whether DC infiltrated the testis during the development of EAO. EAO was induced by active immunization with testis homogenate and adjuvants in two strains of rat (Wistar and Sprague Dawley). The presence of DC in testis was determined, 50 and 80 days after the first immunization, by immunohistochemical staining with specific antibodies (OX-62 and CD11c), and then the total number of DC was measured by stereological analysis. Labeled cells were found only in the interstitial compartment and within granulomas of EAO animals. The number of DC in EAO testes increased compared with control rats in both strains, whereas the number of OX-62+ and CD11c+ cells in adjuvant controls remained unchanged compared with untreated rats. Interspecies variations in the quantity of DC were found, with the total number of DC per testis in untreated and adjuvant control Sprague-Dawley rats being about three times higher than that seen in Wistar rats. Moreover, the increase in DC numbers at 80 days was less prominent in EAO testes of Sprague-Dawley rats than in the Wistar strain in which EAO was more severe and showed a higher number of granulomae. Thus, we have identified the DC population in normal and chronically inflamed testis. The increase in DC observed in EAO suggests that, under inflammatory conditions, the modified action(s) of these cells is a factor in the induction of the autoimmune response in testis.

Quantitative Doppler assessment of acute scrotal inflammation

PURPOSE

To establish quantitative Doppler criteria for acute unilateral epididymitis and/or orchitis.

MATERIALS AND METHODS

Triplex ultrasonography (US) was used to prospectively evaluate 31 patients with acute hemiscrotal pain and 15 asymptomatic control subjects. Morphology and perfusion were assessed, and peak systolic velocities (PSVs) were recorded. Ratios of PSV were calculated by using values from the right and left sides.

RESULTS

PSVs in control subjects differed significantly from those in patients (P < .0001). A PSV > or = 15 cm/sec produced diagnostic accuracy of 90% for orchitis and 93% for epididymitis: Five of six false-negative findings were in patients younger than age 15 years. Epididymal PSV ratios > or = 1.7 or testicular ratios > or = 1.9 were diagnostic of acute inflammation (P < .0001). In three cases, morphologic and color Doppler findings were normal and only the PSV ratios were diagnostic.

CONCLUSION

PSV and PSV ratios provide diagnostic criteria for acute unilateral epididymitis and/or orchitis that are more accurate than morphologic evaluation and color flow imaging either alone or in combination.