Experimental zinc deficiency: effects on cellular responses and the affinity of humoral antibody.

Mice genetically selected for the production of either high- or low-affinity antibody were fed on diets sufficient or deficient in zinc. The effect of zinc deficiency on immune responses in these animals was analysed in terms of cell-mediated responses and the levels and affinity of antibody produced in response to immunization with T-dependent and T-independent antigens. In comparison with animals fed zinc-containing diets, mice fed zinc-deficient diets had reduced numbers of T cells and T-cell subsets, reduced proliferation to mitogens and specific antigen, and a decreased production of interleukin 2 (IL-2), but the number and affinity of IL-2 receptors were not affected. Furthermore, zinc-deficient animals produced reduced levels of antibody to the T-dependent antigen DNP-human serum albumin, but the affinity of this antibody was significantly elevated compared with that produced by zinc-sufficient animals. However, zinc deficiency had no effect on the levels and affinity of antibody produced to the T-independent antigen DNP-ficoll.