Substances present in our environment influence the whole organism, including the immune system. Metals are one of the principal parts of these substances. It is generally supposed that they may have stimulating effect on immunity system in low concentrations in comparison with high concentrations in which they are toxic, with variations of each metal. There are differences between for example cadmium and zinc, and cadmium is toxic in low concentrations either. The effect of cadmium on the immune system has not been studied so deeply as the influence of zinc. In our work, we are interested in the study of immunomodulation caused by cadmium in comparison with the influence of zinc. We tested the effect of cadmium and zinc sulphates on human T lymphocytes in vitro. Molar concentrations of salts used in our work were from 10 -2 M to 10 -10 M. The influence of metals on lymphocytes in cell culture was studied by the expression of surface antigen CD69, blast transformation and IL-2 and IL-4 intracellular production after 2, 24 and 72 h cultivation. Cells were analyzed by flow cytometry using monoclonal antibodies. The results show more expressive differences in blast transformation. There are stimulating effects of cadmium in concentrations 10 -3 M, 10 -4 M and 10 -8 M, and zinc 10 -3 M. The most suppressive effect is in concentrations 10 -10 M of cadmium and 10 -8 M of zinc. The highest CD69 expression is in concentrations 10 -4 M and 10 -6 M of cadmium, and 10 -3 M of zinc. There are minimal differences in intracellular cytokine production in CD4+ lymphocytes effected by various metal concentrations used and between cadmium and zinc salts after 2 hours cultivation. There is the elevation of cytokines negative cells after the cultivation lasting 24 hours. Our investigation of metals' influence by different methods shows possibilities for further research.

        Key words: cadmium, zinc, CD69, blast transformation, intracellular cytokines, flow cytometry