Induction of experimental autoimmune orchitis by immunization with xenogenic testicular germ cells in mice

Mechanisms underlying impaired spermatogenic function in orchitis induced by busulfan

Busulfan is an alkylating agent commonly used in cancer chemotherapy. It is also an ideal agent for preparing transplant recipients of spermatogonial stem cells because of its high efficiency in destroying endogenous germ cells in the testis. However, its toxicity mechanism remains unclear, affecting its clinical use and applications. Based on reports of busulfan causing orchitis and a previous study by our team, this article summarizes the relationship between busulfan and orchitis, cytokines, the blood-testis barrier, and the cytoskeleton, unravels the regulatory pathways and mechanism behind busulfan-induced orchitis, and reveals the molecular mechanism underlying impaired spermatogenic function in orchitis, providing new ideas for the clinical application of busulfan while reducing its testicular toxicity.

Immunological microenvironment in the testis

BACKGROUND

The testis is specific in that it produces haploid germ cells of which autoantigens newly appear long after the neonatal immune tolerance. Under normal condition, these autoantigens are protected by the blood-testis barrier formed by Sertoli cells. Thus, the testis is an immunologically privileged site where haploid cells are protected from autoimmune attack.

METHODS

The immunological microenvironment in the testis was experimentally investigated using mice and rats.

MAIN FINDINGS

Not only the blood-testis barrier but also various immuno-suppressive factors are involved in the immune-privileged testis. Indeed, germ cells transplanted into the xenogeneic seminiferous tubules could proliferate and differentiate with no aid of artificial immunosuppression. On the other hand, autoimmune orchitis could be experimentally produced by various methods of immunization with syngeneic or xenogeneic germ cell antigens.

CONCLUSION

Our results indicate that the testis is immunologically privileged but also immunologically fragile organ. Therefore, the dual nature is critical for immunoregulation of testicular function.

The effectiveness of traditional Japanese medicine Goshajinkigan in irradiation-induced aspermatogenesis in mice

Background

Infertility and gonadal dysfunction are well known side-effects by cancer treatment in males. In particularly, chemotherapy and radiotherapy induced testicular damage, resulting in prolonged azoospermia. However, information regarding therapeutics to treat spermatogenesis disturbance after cancer treatment is scarce. Recently, we demonstrated that Goshajinkigan, a traditional Japanese medicine, can completely rescue severe busulfan-induced aspermatogenesis in mice. In this study, we aimed to detect the effects of Goshajinkigan on aspermatogenesis after irradiation.

Methods

This is animal research about the effects of traditional Japanese medicine on infertility after cancer treatment. C57BL/6 J male mice received total body irradiation (TBI: a single dose of 6Gy) at 4 weeks of age and after 60 days were reared a Goshajinkigan (TJ107)-containing or TJ107-free control diet from day 60 to day 120. Then, two untreated females were mated with a single male from each experimental group. On day 60, 120 and 150, respectively, the sets of testes and epididymis of the mice in each group after deep anesthetization were removed for histological and cytological examinations.

Results

Histological and histopathological data showed that 6Gy TBI treatment decreased the fertility rate (4/10) in the control diet group; in contrast, in the TJ107-diet group, the fertility rate was 10/10 (p < 0.05 vs. 6Gy group). Supplementation with TJ107 was found to rescue the disrupted inter-Sertoli tight junctions via the normalization of claudin11, occludin, and ZO-1 expression and reduce serum anti-germ cell autoantibodies.

Conclusions

These findings show the therapeutic effect on TBI-induced aspermatogenesis and the recovering disrupted gonadal functions by supplementation with TJ107.