[Chronological changes in autoantigenicity of autologous testicular germ cells in C3H/He mice during the postnatal period].

Our recent studies demonstrated that experimental autoimmune orchitis (EAO) model was produced in C3H/He mice with high incidence by two subcutaneous injections of viable syngeneic testicular germ cells (TC) without the use of any adjuvants or immunopotentiators. In this study the developmental patterns of autoantigenicity of TC during postnatal period were investigated by examining the orchitogenic activity of TC, the lymphostimulatory activities of TC (including the TC-induced in vitro lymphocyte proliferative response and the cytokine release from sensitized spleen cells (SPC) in response to TC) and the immunohistochemical localization of target autoantigens in the testes of mice at various weeks of age. Delayed-type hypersensitivity-inducing capacity and anti-TC antibody-eliciting capacity were initially observed in mice that were immunized with TC of 4-week old (w.o.) mice. The TC from 6-w.o. mice had the capability of inducing EAO (orchitogenicity) for the first time. A significant stimulation of in vitro lymphocyte proliferative response, as well as of interleukin (IL) 5 and IL-6 production by sensitized SPC were detectable when TC of mice 3-w.o. or more than were employed as stimulant. IL-2 and interferon gamma production were detected with TC of 4-w.o. mice. Immunohistochemical staining reaction with anti-TC antisera was primarily localized at the acrosomal portion of spermatids and spermatozoa in the seminiferous tubules, being already detected in spermatids of as early as 3-w.o. mice. Thus, from these data it is suggested that the appearance of the lymphostimulatory activities of TC consistently precedes that of the orchitogenic activity and that relatively mature germ cells such as spermatids and spermatozoa developing in the testes during the postnatal weeks may be responsible for the induction of disease and relevant immune responses in our EAO system.