COPPER REPLETION RESTORES THE NUMBER AND FUNCTION OF CD4 CELLS IN COPPER-DEFICIENT RATS

Dietary copper deficiency decreases the number of splenic CD4 cells an d mitogen-induced generation of interleukin-2 activity and DNA synthes is in cultures of splenic mononuclear cells. To determine the reversib ility of these defects, Cu-deficient rats were fed a Cu-adequate diet for either 4, 7 or 11 d before preparation of cell cultures. Serum and hepatic concentrations of Cu attained 87 and 75%, respectively, of th e control level after 4 d of dietary repletion. In contrast, interleuk in-2 activity and [H-3]thymidine incorporation in splenic cell culture s treated with T-cell mitogens were significantly greater than in cult ures from Cu-deficient rats after 7, but not 4, d of dietary Cu replet ion. The number of splenic CD4 cells was also greater after 7 d of die tary supplementation with Cu. Changes in the relative percentage and f unction of T-helper cells were highly correlated with one another and with hepatic Cu concentration. These observations indicate that an ina dequate supply of dietary Cu reversibly suppresses the maturation and function of splenic T-helper cells.