The influence of Aclacinomycin A on the immune response and on experimental immune disorders

The anti-cancer drug Aclacinomycin A (ACM) was able to inhibit the humoral immune response of mice against sheep red blood cells. This could be demonstrated in the formation of antibody secreting cells (PFC) and serum antibody titers, when ACM was administered either together with the antigen or three days after antigen application. Cellular immunity was not affected by the drug. In two murine Graft-vs-Host (GvH) disease models leading to two different B cell dependent auto-immune diseases (immune complex glomerulonephritis and immune hemolytic anemia) a protective effect of ACM was observed when it was administered at the time of the graft. The application of ACM in the induction phase mitigated the development of glomerulonephritis and prevented animals from dying due to hemolytic anemia. Only a slight therapeutical effect was observed when ACM was given after the appearance of clinical symptoms. In a T cell induced auto-immune disease (experimental allergic encephalomyelitis (EAE], ACM had no discernible effect on the course of the disease. It seems that the therapeutic effects of ACM on GvH-diseases are mediated via suppression of B-lymphocytes.