Selective immunosuppression following exposure to a novel anthraquinone, 1,4-bis[(2-aminoethyl)amino]-5,8-dihydroxy-9,10-anthracenedione dihydrochloride (AEAD).

The immune response of murine splenic lymphocytes was characterized following both in vivo and in vitro exposure to the novel and highly-substituted anthraquinone AEAD. Gross indicators of toxicity such as changes in body weight, lymphoid organ weights or lymphoid organ cellularity were unaffected. Similarly, the antibody plaque-forming cell response and natural killer cell function were unaltered. The most consistent effect noted was the selective suppression of the cytotoxic T-lymphocyte (CTL) response, which persisted for an extended period of time following in vivo exposure at concentrations of 0.75-3.0 micrograms/g. In contrast to the CTL suppression induced by the polycyclic aromatic hydrocarbon 7,12-dimethylbenz[a]-anthracene, AEAD-induced CTL suppression could not be restored by addition of exogenous interleukin-2. Studies are currently underway to further characterize AEAD-induced immunosuppression at the cellular and molecular levels.