Effect of aging on the autoimmune response to sex accessory glands in male rats.

The effect of aging on the immune response to autoantigen of rat male accessory glands (RAG) was studied in Wistar rats. Male and female rats, 3 and 12 months old, were immunized with chemically modified RAG and heterologous antigen (human serum albumin, HSA). The study of delayed type hypersensitivity (DTH) and antibodies against RAG revealed a higher response in 12-month-old animals than in 3-month-old animals (P less than 0.005), regardless of their sexes. No differences in DTH and humoral responses to HSA were observed. Experiments on the transfer of spleen cells showed an increase in response elicited by RAG immunization in young recipients of cells from normal or immunized old syngeneic donors. On the contrary, old recipients of spleen cells from normal or immunized young donors maintained their high response the same as non-transferred old rats. Therefore, both the lymphoid cells and the environment in which the response was elicited seem to be involved in the increase of the autoimmune response.