Alterations in splenic lymphoid cell subsets and activation antigens in copper-deficient rats.

Rats were nursed by dams fed a diet containing adequate (6 micrograms/g) or deficient (0.6 micrograms/g) Cu during the lactation period and weaned to the same diet. Splenic mononuclear cells were isolated and the phenotypic profile determined by flow cytometry after immunolabelling with monoclonal antibodies to cell surface markers. Total splenic mononuclear cell yield and the relative percentage and absolute number of T-cells and the CD4+ (helper) and CD8+ (cytotoxic) T-subsets were decreased in Cu-deficient male rats. The relative percentage, but not the absolute numbers, of splenic B-cells and macrophages was increased by Cu deficiency. The percentage of splenic mononuclear cells from male rats that expressed interleukin-2 receptors and transferrin receptors in vivo was increased by Cu deficiency. In contrast, dietary Cu deficiency did not affect the yield and phenotypic profile of splenic mononuclear cells in female rats. Reactivity of splenic mononuclear cells to T-cell mitogens was decreased in Cu-depleted male and female rats. However, mitogen-induced increases in levels of interleukin-2 receptor and transferrin receptor were similar in cultures of splenic mononuclear cells obtained from control rats and rats subjected to restricted dietary intake of Cu only during the postlactation period. Thus, decreased mitogenic blastogenesis on exposure of cells from Cu-deficient rats does not reflect a nonspecific impairment of cellular activation.