Aclacinomycin-A inhibits the development and the expression of suppressor cell activity to contact sensitivity.

Aclacinomycin-A, a cytotoxic antibiotic, is capable of inhibiting the development and expression of suppressor cell activity for the contact sensitivity reaction to picryl chloride elicited by two intravenous injections of 3.5 mg picryl sulfonic acid when given as a single dose of 4 mg/kg 2 or 4 days before the first or 1 or 3 days after the second injection of picryl sulfonic acid. This inhibition may occur because aclacinomycin-A inhibits the development and expression of both suppressor T-cells and their precursors. In addition, it is shown that aclacinomycin-A diminishes the capacity of spleen T-cells from picryl sulfonic acid-injected mice to inhibit upon adoptive transfer the contact sensitivity reaction to picryl chloride of normal and presensitized animals.