Low-frequency electromagnetic fields do not alter responses of inflammatory genes and proteins in human monocytes and immune cell lines.

The effects of low frequency electromagnetic fields (LF EMF) on human health are the subject of on-going research and serious public concern. These fields potentially elicit small effects that have been proposed to have consequences, either positive or negative, for biological systems. To reveal potentially weak but biologically relevant effects, we chose to extensively examine exposure of immune cells to two different signals, namely a complex multiple waveform field, and a 50 Hz sine wave. These immune cells are highly responsive and, in vivo, modulation of cytokine expression responses can result in systemic health effects. Using time course experiments, we determined kinetics of cytokine and other inflammation-related genes in a human monocytic leukemia cell line, THP-1, and primary monocytes and macrophages. Moreover, cytokine protein levels in THP-1 monocytes were determined. Exposure to either of the two signals did not result in a significant effect on gene and protein expression in the studied immune cells. Also, additional experiments using non-immune cells showed no effects of the signals on cytokine gene expression. We therefore conclude that these LF EMF exposure conditions are not expected to significantly modulate innate immune signaling.