Temporal recognition of sperm autoantigens by IgM and IgG autoantibodies after vasectomy and vasovasostomy

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.

Identification of post-vasectomy sperm auto-antigens in fox (Vulpes vulpes) by two-dimensional gel electrophoresis and Western blotting

The aim of this work was to identify antigenic surface proteins on fox spermatozoa. Six foxes were inguitinally vasectomised, and the time course of antibody response in the sera was studied. Five out of the six foxes reacted to vasectomy with a production of antisperm antibodies. The number of bands recognised by Western blot was maximal 120-150 days after the vasectomy, at the end of the reproductive season. On the whole, 30 bands were recognised between 9 and 150 kDa. The pattern of recognised proteins varied from one fox to another. The humoral response was studied in one fox 2 years after the vasectomy, before, during and after the breeding season. The same proteins were recognised, but the intensity of staining was increased during the testis regression. Using FITC-labelling on sperm smears with fox sera, antigens were localised at or near the sperm surface, either on the acrosome or both on the acrosome and on the flagellum. Using two-dimensional gel electrophoresis and Western blotting, we identified eight areas containing major antigens, recognised by at least two sera. The molecular weights (kDa) and isoelectric points of the repeated antigens were, respectively [150, 6.6-6.0]; [105-98, 6.0-5.5]; [97, 4.6-4.3]; [95, 5.0]; [85-80, 5.4-5.1]; [42, 5.0-4.8]; [17-15, 6.5-5.9]; and [17-15, 5.5-4.8]. The results of this study can be used to characterise more precisely fox sperm auto-antigens by microsequencing the selected proteins.

Serial ultrasonography, hormonal profile and antisperm antibody response after testicular sperm aspiration

BACKGROUND

In many fertility centres, intracytoplasmic sperm injection (ICSI) with epididymal or testicular spermatozoa is a routine treatment for men with azoospermia. In this prospective study, the physiological consequences after testicular sperm aspiration (TESA), using suction and a 19 gauge needle, were evaluated.

METHODS AND RESULTS

Thirty-five consecutive men with azoospermia underwent TESA. Testicular ultrasonography with Doppler flow imaging was performed and testicular volumes were evaluated pre-operatively and 3 months after aspiration. If focal testicular lesions were found, further examinations were performed 6 and 9 months after TESA. Serum FSH, testosterone and antisperm antibodies (ASA) were analysed. Focal testicular lesions were seen in four out of 61 testes (6.6%) at the 3 month investigation point. Three lesions were resolved after 6 months and all after 9 months. Testicular echogenicity remained unchanged in 50 cases (82%) 3 months after TESA. Four men (11.4%) reported severe subjective discomfort post-operatively, but only one had a medical consultation where an intratesticular haematoma was diagnosed. There were no significant changes in FSH and testosterone after surgery and testicular volumes were similar after 3 months. There were three borderline cases of ASA in serum, but none was classified as ASA-positive.

CONCLUSIONS

The puncture method of testicular sperm aspiration seems to be a safe method for sperm retrieval, with minimal physiological consequences.

Cellular responses to vasectomy

A number of cell populations in the reproductive tract show a response to vasectomy. Some cell types show similar responses in man and all laboratory species, whereas others show marked species variations. This chapter describes these effects in a broadly chronological order and, in a general way, considers changes close to the site of vasectomy first and the longer term effects on the testis itself later. Following vasectomy, epididymal distension and sperm granuloma formation result from raised intraluminal pressure. The sperm granuloma is a dynamic structure and a site of much spermatozoal phagocytosis by its macrophage population. In many species, spermatozoa in the obstructed ducts are destroyed by intraluminal macrophages, and degradation products, rather than whole sperm, are absorbed by the epididymal epithelium. Humoral immunity against spermatozoal antigens following vasectomy is well established and there is evidence of modest T-lymphocyte activity. The role of lymphocytes in the reproductive tract epithelium and interstitium following vasectomy is poorly defined. In laboratory animals, there is evidence that pressure-mediated damage to the seminiferous epithelium can follow sperm granuloma formation and obstruction in the epididymal head. However, the contribution of lymphocytes and antisperm antibodies to testicular damage after vasectomy is far from clear. A number of studies have suggested that testicular changes may follow vasectomy in man but their validity and mechanism of occurrence require further study.

Post-obstruction rat sperm autoantigens identified by two-dimensional gel electrophoresis and western blotting

Although antisperm autoantibody responses to obstruction of the male reproductive system have been documented, information on the nature of the cognate sperm autoantigens has been limited. In the present study, the patterns of sperm autoantigens recognized by sera from rats after obstruction of the vas deferens or epididymis were studied by high resolution two-dimensional (2-D) gel electrophoresis and western blotting. Comparisons of patterns of autoantigens stained on 2-D western blots of sera from prepubertal vasectomy, prepubertal epididymal ligation and adult vasectomy groups revealed both similarities and differences. Sera from sham-operated animals showed no detectable reaction or much lighter staining of a small number of spots. Visualization of sperm autoantigens on 2-D western blots supported the hypothesis that there is a relatively small set of sperm proteins that can be regarded as dominant post-obstruction sperm autoantigens because they are recognized by multiple post-obstruction sera. The 2-D analysis revealed previously undetected distinctions in the autoantigens recognized after adult and prepubertal vasectomy, as well as variations with the site of obstruction. These differences in the response may be due in part to changes in antigens of spermatozoa in different parts of the tract and at different ages, as well as variations in exposure of sperm cell proteins to the immune system resulting from the sites of spermatic granulomas. Preparative 2-D gels and western blotting with post-obstruction sera are now being used to identify specific sperm autoantigens by microsequencing of selected proteins.

Antisperm antibodies: etiology, pathogenesis, diagnosis, and treatment

OBJECTIVE

To critically review the English-language literature and describe the current diagnosis, prevalence, etiology, and treatment of antisperm antibodies (ASA).

DESIGN

A comprehensive literature search of the English-language literature published between 1966 and December 1997 was performed on MEDLINE. Articles were also located via bibliographies of published works.

RESULT(S)

Data were excerpted from articles identified by MEDLINE search. The diagnosis, prevalence, etiology, and treatment of ASA are described.

CONCLUSION(S)

There is sufficient evidence that ASA impair fertility in couples with unexplained infertility. A number of different methodologies are available, which may be used in their detection. However, in many cases, test interpretation is subjective. Although there is not enough evidence to support systemic treatment for ASA, application of a variety of assisted reproductive technologies improves outcome.

Autoantigenicity of the basal compartment of seminiferous tubules in the rat

The expression of testicular autoantigens has been thought to be restricted to the luminal compartment of the seminiferous tubules. In the present study it was observed that germ cells in the basal compartment of seminiferous tubules and lamina propria of the seminiferous tubule bound antibodies in anti-testis immunosera in vivo after passive transfer of the sera by intra-peritoneal injection. The anti-testis immunosera were prepared in orchiectomised rats to avoid pre-collection adsorption of antibodies in the basal compartment of the seminiferous tubules. When testis-immune sera collected from non-orchiectomised rats or normal sera were transferred no such binding of antibodies to the basal germ cell surface or the lamina propria occurred. In Western blot analysis the anti-testis immune sera prepared in orchiectomised rats defined polypeptides from the adult rat testis with relative MWs of 19-23, 26-28, 30, 34, 38, 40-43, 45-47, 51-52, 56-57, 68, 78 and 97 kDa. The 40-43 kDa band was not detected by sera prepared in non-orchiectomised rats, suggesting that this autoantigen was expressed in the basal compartment of the seminiferous tubules. These observations suggest that the segregation of testicular autoantigens in the luminal compartment of seminiferous tubules is not complete for all of them in the rat and emphasize the role of more dynamic mechanisms in prevention of anti-germ cell autoimmune disease.