Immunopharmacology of gold sodium thiomalate and auranofin (SK&F D-39162): effects on cell-mediated immunity.

The effects of gold sodium thiomalate (GST) and auranofin (SK&F D-39162) on cell-mediated immunity were investigated using oxazolone-induced contact sensitivity and delayed hypersensitivity to sheep red blood cells. C57Bl mice were sensitized to oxazolone on day 0 and challenged either 45 or 72 h later. The resulting paw edema was read plethysmographically 24 h after challenge. GST and auranofin both were capable of stimulating oxazollone-induced contact sensitivity which was compromised by using a shortened sensitization period (45 h). Auranofin but not GST stimulated the response to oxazolone in immunosuppressed mice, but neither agent significantly altered the uncompromised response in normal mice. The stimulatory effect of auranofin and GST on cell-mediated immunity was corroborated using SRBC to induce delayed hypersensitivity. Comparison of blood Au levels revealed that gold in the form of auranofin was approximately 4x more effective in stimulating cell-mediated immunity than was gold in the form of GST. These results were suggested to be due to the possible stimulation by gold of T effector as well as T suppressor lymphocytes, thus explaining the condition dependency of the immunoregulation.