Splenic cytokines in mice immunized with testicular germ cells

Abstract

We previously established that two subcutaneous injections of viable syngeneic testicular germ cells (TGC) alone can induce CD4+ T cell-dependent experimental autoimmune orchitis (EAO) in mice. This model is histologically characterized by lymphocytic infiltration into the testes and the following aspermatogenesis. In the present study, we investigated the dynamics of splenic cytokines in EAO, using specific enzyme-linked immunosorbent assay. We found that splenic production of both type 1 helper T cell (Th1) and type 2 helper T cell (Th2)-related cytokines increased after the second but not the first immunization with TGC, indicating that secondary immune responses are critical to the EAO induction. However, the production of Th1-related cytokines became predominant at the clinical stage of EAO. Additionally, serum FSH and inhibin-B increased and decreased, respectively, during EAO. On the other hand, LH did not significantly change and testosterone temporally increased during the same period. These results indicate that both Th1- and Th2-related cytokines are involved at the pre-clinical phase of EAO, but that Th1- rather than Th2-related cytokines are responsible for the clinical phase when spermatogenesis is disrupted but the Leydig cell function is well preserved.

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

“…In the present study, a significant increase of testicular IL-6 mRNA expression was not detected. This is an unexpected results, because IL-6, a cytokine that activates B lymphocytes and promotes development of antibody production, was significantly secreted by splenic lymphocytes isolated from TGC-immunized mice [12,18]; furthermore, significant numbers of B lymphocytes and plasma cells were found in EAO lesions with the production of serum autoantibodies [33,34]. This discrepancy between testicular and splenic IL-6 indicates that intratesticular Th1 immune responses are critical during EAO lesions and that systemic Th2 responses outside the testis affect infiltration of lymphocytes of B cell lineage into the testis.…”

“…Both IFN-γ and TNF-α were detected from cultured spleen cells and lymph node cells in EAO-induced mice in vitro [12,18]. Through in vivo studies, the effects of these two cytokines were investigated by administration of anti-IFN-γ and anti-TNF-α monoclonal antibodies.…”

“…However, in spite of no use of these adjuvants, it was found that delayed type hypersensitivity rather than humoral immunity against TGC antigens is critical for induction of the disease [2,11,12]. It was also shown that spleen cells of TGC-immunized mice secrete IFN-γ in vitro and that EAO was successfully suppressed on treatment with anti-IFN-γ monoclonal antibodies [12,13]. In other studies, local injection of IFN-γ and TNF-α into normal testes was shown to induce cytotoxicity to TGC in vivo [14,15].…”

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

“…In EAO, adeno-associated virus-mediated human IL-10 gene transfer suppressed the development of the disease ( Watanabe et al 2005). However, it exerts the opposite effect in some autoimmune diseases including EAO (Rosenbaum & Angell 1995, Hill & Sarvertnick 2002, Kaneko et al 2003, Tokunaga et al 2008. Although pathophysiological effects of these two cytokines on the epididymal tissues remain unclear, the Vx-induced elevation of the epididymal cytokines may attract inflammatory cells to the epididymis rather than the testis.…”

“…We previously demonstrated that immunization of C3H/He and A/J mice with viable syngeneic testicular germ cells (TGC) alone induces EAO without an adjuvant (Itoh et al 1991a, 1991b, Tokunaga et al 2008. However, this EAO model is very unique in which orchitis can occur without epididymitis.…”