Zinc modulates the mitogenic activation of human peripheral blood lymphocytes

In the present study we have investigated the effect of Zn salts on the mitogenetic activation of human peripheral blood lymphocytes (PBL). Our results show that Zn2+ enhances the level of DNA synthesis in human T lymphocytes stimulated by a mitogenic lectin, phytohemagglutinin (PHA); this effect seems to be mediated through an enhanced expression of both interleukin-2 (IL-2) and transferrin (Trf) receptors. We have also analyzed the mitogenic effect of Zn2+ alone on PBL, in the absence of other mitogenic stimuli. In this regard we have identified large light density T lymphocytes as the PBL population which is activated to proliferate by Zn2+. Finally, we showed that Zn2+ stimulates natural killer (NK) activity; this effect is apparently not due to a direct action on NK lymphocytes, but is related to endogenous cytokines released by accessory cells which in turn stimulate the cytolytic activity of NK lymphocytes.