Cadmium Inhibits IL-6 Production and IL-6 mRNA Expression in a Human Monocytic Cell Line, THP-1

Cadmium is a known immunotoxic agent in animal studies. Cells of the mononuclear phagocytic system are strategically located at portals of entry in humans and therefore may be particularly at risk for cadmium exposure through contaminated air, food, and drinking water. The purpose of this study was to determine whether there were changes in interleukin-6 (IL-6) production, a pleiotropic cytokine, when an activated human monocytic cell line was exposed to cadmium. Results suggest that there were statistically significant lower levels of IL-6 at 0.06 mM cadmium (P < 0.05), and 0.8 and 0.1 mM cadmium (P < 0.01), determined via the ELISA method. IL-6 messenger RNA (mRNA) levels were also decreased at these cadmium concentrations. The addition of a chelating agent, EDTA, to the cultures prevented the suppression of IL-6 secretion.