Adjuvant effect of liposomes in the autoimmune response to rat male accessory glands

Wistar rats submitted to 3 intravenous (i.v.) or intraperitoneal (i.p.) immunizations with saline extract of rat male accessory glands (RAG) associated to liposomes developed a delayed type hypersensitivity (DTH) response to RAG after the first immunization, a remission state after the second immunization and a specific DTH response after the third injection. In a further study we transferred spleen mononuclear (SpM) cells from i.p. immunized rats taken 10 days after the second immunization (DTH negative) to normal or immunized recipients 24 h before or 10 days after the first immunization with RAG liposomes, respectively. The DTH response was reduced only in recipients previously immunized. Besides, it was possible to show that the transfer of SpM cells present when the response increased after the third injection in i.p. immunized donors reduced the suppression observed after the second injection. Rat accessory gland biopsies taken 10 days after the last immunization showed in nearly all cases mast cells, plasma cells and eosinophils with scarce lymphoid elements and increased acinar desquamation. This kind of infiltration had characteristics of cutaneous basophil hypersensitivity.