Antigen‐induced inhibition of autoimmune response to rat male accessory glands: distinct role of I‐A and I‐E‐positive peritoneal cells

Abstract

The present report describes the structural and functional characteristics of the population of peritoneal cells (PC) from rats injected intraperitoneally (i.p.) 2 h or 24 h previously with a suppressor dose of a purified fraction (FI) of rat male accessory glands (RAG: FI-PC2h and FI-PC24h, respectively). Both populations of PC showed the presence of the autoantigens of RAG on their membrane. The study of cell surface marker showed increase of OX17 (I-E) in FI-PC2h and OX6 (I-A) in FI-PC24h. I.p. injection of FI-PC2h 10 and 3 days prior to immunization with chemically modified (diazotized arsanilic and sulfanilic acid) RAG (MRAG) in complete Freund's adjuvant induced suppression of the delayed-type hypersensitivity (DTH) response to MRAG, whereas the i.p. injection of FI-PC24h induced potentiation of DTH response to MRAG when compared with controls (animals injected 10 and 3 days prior to immunization with PC from rats injected i.p. with an unrelated antigen). The treatment of FI-PC2h with OX17 and FI-PC24h with OX6 prior to the transfer blocked the suppression and potentiation described above. These findings show that the i.p. injection of an FI of RAG at a suppressor dose induces PC with immunologically opposite characteristics, depending on the time of obtention.

Experimental autoimmune encephalomyelitis: Antigen-induced inhibition of biochemical and immunohistological alterations

“…Using another experimental model of autoimmunity against rat male sex accessory glands induced by immunization with a chemically modified accessory gland saline extract (MRAG) in complete Freund's adjuvant (CFA), we have previously shown that a purified fraction of rat male accessory glands intraperitoneally administered in low doses and soluble form prevents the cellular and humoral autoimmune response when animals are subsequently challenged with MRAG in CFA (Ferro et al , 1985(Ferro et al , , 1990Rivero et al, 199 1). Application of a similar experimental model to EAE demonstrated inhibition of the clinical signs of the disease with a concurrent suppression of the proliferative response of mononuclear cells to MBP (Rivero et al, 1995(Rivero et al, , 1996.…”

Effect of aging on the autoimmune response to rat male accessory glands: deficit of I‐E‐positive peritoneal cells capable of inducing suppression

“…Moreover, the inhibition was antigen specific because the RAG FI-pretreated animals could effectively mount an immune response to Tuxoplasma gondii antigens [20]. The cell types involved in the suppression included MRAG-specific, cyclophosphamide CY-sensitive, inducer-phase Ts cells, CYand irradiation-sensitive, effector-phase suppressor cells and I-E+ APC [7,21]. The results presented here show clearly that it is more difficult to induce suppression to autoantigen of RAG in old rats.…”

“…Taken together, these findings support our previous results on the role of I-E+ PC in the induction of suppression in RAG autoimmunity. In fact, it was previously demonstrated [7] that I-E+ PC from rats injected i.p. with FI of RAG,but not with an unrelated antigen,were involved in the induction of MRAG-specific inducer-phase T, cells and that I-A+ PC from FI of RAG-pretreated rats were involved in the induction of cells responsible for the autoimmune response.…”

“…In this study, we have analyzed the ability to induce suppression to RAG autoantigens and the characteristics of TJnducer peritoneal cells (PC) of old rats using an experimental model of suppression of autoimmunity to RAG [6,7], in which antigen-specific inducer-phase T, cells, effector-phase suppressor cells and I-E+ APC are involved.…”