• Autoimmunity;
  • rats;
  • immunosuppression;
  • adoptive transfer

ABSTRACT: The injection of the spleen mononuclear (SpM) cells, obtained from rats rendered unresponsive to autoantigen of rat male accessory glands (RAG) by pretreatment with low doses of purified fraction of RAG (containing the autoantigen), into normal syngeneic recipients markedly prevented the development of delayed type hypersensitivity (DTH) reaction to the autoantigen (suppression of the induction) (p < 0.001). The humoral response was not altered. The control animals were rat receptors of spleen mononuclear cells from donor rats pretreated with rat lung saline extract or 0.15 M NaCl. In contrast, the transference of SpM cells from donor rats pretreated with low doses of autoantigen prior to the immunization to rats previously immunized, did not modify the expression of the immune response against the autoantigen when compared with control rats. The suppression of the induction of DTH response was also obtained when prior to the immunization, the recipients received T-cell-enriched SpM cell population from unresponsive animals (p < 0.001), but not when they were injected with B-cell-enriched SpM cells. These results suggest that suppressor T cells capable of controlling induction of the autoimmune response against RAG autoantigen might be one of the immunoregulatory mechanisms that are activated when soluble autoantigen of RAG enter into circulation.