Characterization of an immunoregulatory cell subset involved in the up-regulation of the autoimmune response to rat male accessory glands.

Abstract

We studied the regulation of the autoimmune response to rat male accessory glands (RAG) using liposomes as adjuvants. Adult male Wistar rats were submitted to three intraperitoneal (i.p.) immunizations with 750 micrograms of saline extract of RAG associated with liposomes. The delayed type hypersensitivity (DTH) response studied approximately 10 days after each immunization developed after the first immunization, having a remission state after the second one and a clear increase after the third injection. In a further study, spleen mononuclear (SpM) cells obtained form immunized rats 10 days after the third immunization (DTH positive) or from normal rats were separated as adherent (VV+) or nonadherent (VV-) to Vicia villosa population. In VV+ SpM cells from immunized or normal animals an enhanced percentage of OX8+ cells (P < .05 and P < .01, respectively) was found, but in VV- SpM cells from the same groups of rats an enhanced percentage of W3/25+ cells (P < .01 and P < .05, respectively) was found when they were studied by immunofluorescence. Later on, we transferred total VV+ or VV- SpM cells from i.p. immunized rats to immunized recipients 10 days after the second immunization (DTH negative). The DTH response was enhanced in recipients of total or VV+ SpM cells (P < .01). It was also observed that the transfer of VV- SpM cells from immunized rats or total or VV+ SpM cells from normal rats did not reduce the suppression state observed after the second injection (P = NS). The total SpM cells obtained 10 days after the third immunization (DTH positive) were able to transfer autoimmune response to RAG to normal animals (P < .01), whereas VV+ SpM cells did not show that capacity (P = NS).