Medical/biological study (experimental study)

Extremely low frequency electromagnetic field exposure does not modulate toll-like receptor signaling in human peripheral blood mononuclear cells. med./bio.

By: de Kleijn S, Bouwens M, Verburg-van Kemenade BM, Cuppen JJ, Ferwerda G, Hermans PW

Published in: Cytokine 2011; 54 (1): 43-50

Aim of study (acc. to author)

To study the effect of extremely low frequency electromagnetic fields on a variety of components of the human innate immune system in a standardized in vitro cellular model.

Background/further details

Human peripheral blood mononuclear cells, isolated from blood from six healthy volunteers, were stimulated with specific TLR2 and TLR4 ligands (lipopolysaccharides and/or Pam3Cys) , or with several microorganisms and subsequently exposed (at different time points after stimulation). The Toll-like receptor (TLR) family is an important factor in the fast first response to invading pathogens.

Endpoint

cell function: cytokine production

Exposure

Exposure	Parameters
Exposure 1: 20 Hz–5 kHz Exposure duration: continuous for 30 min	magnetic flux density: 5 µT magnetic flux density: 3 µT maximum (DC ambient value)

Exposure 1

Main characteristics

Frequency	20 Hz–5 kHz
Type	magnetic field
Exposure duration	continuous for 30 min

Exposure setup

Exposure source	solenoid
Chamber	exposure system situated in a standard cell culture incubator
Setup	double cylinder; inner cylinder with double copper wire solenoid coil; outer cylinder with windings on both ends to reduce fringe fields

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	5 µT	-	calibration	-	-
magnetic flux density	3 µT	maximum	measured	-	DC ambient value

Additional parameter details

incubator shields a major part of the ambient DC magnetic field from 47 to 3 µT

Exposed system:

intact cell/cell culture

Methods Endpoint/measurement parameters/methodology

cell function: cytokine production (different interleukins and TNF-alpha; at different time points after exposure

Investigated system:

intact cell/cell culture
cell supernatants

Time of investigation:

after exposure

Main outcome of study (acc. to author)

No significant difference in immune response, as reflected by different interleukin production could be detected after stimulation with LPS (TLR4 ligand), Pam3Cys (TLR2 ligand) or a panel of heat killed microorganisms (multiple TLR ligands). The authors conclude that under these experimental conditions, extremely low frequency electromagnetic fields did not modulate the innate immune response of human primary cells after TLR stimulation in vitro.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

ZonMw, The Netherlands

D'Angelo C et al. (2015): Experimental model for ELF-EMF exposure: Concern for human health.
Golbach LA et al. (2015): Calcium signalling in human neutrophil cell lines is not affected by low-frequency electromagnetic fields.
Salehi I et al. (2013): Exposure of rats to extremely low-frequency electromagnetic fields (ELF-EMF) alters cytokines production.
Bouwens M et al. (2012): Low-frequency electromagnetic fields do not alter responses of inflammatory genes and proteins in human monocytes and immune cell lines.
Selmaoui B et al. (2011): Acute exposure to 50-Hz magnetic fields increases interleukin-6 in young healthy men.
Gomez-Ochoa I et al. (2011): Pulsed electromagnetic fields decrease proinflammatory cytokine secretion (IL-1beta and TNF-alpha) on human fibroblast-like cell culture.
Salerno S et al. (2009): Reversible effect of magnetic fields on human lymphocyte activation patterns: different sensitivity of naive and memory lymphocyte subsets.
Cuppen J et al. (2007): Immune stimulation in fish and chicken through weak low frequency electromagnetic fields.
Elmusharaf MA et al. (2007): Antagonistic effect of electromagnetic field exposure on coccidiosis infection in broiler chickens.
Salerno S et al. (2006): Reversible effect of MR and ELF magnetic fields (0.5 T and 0.5 mT) on human lymphocyte activation patterns.
Ikeda K et al. (2003): No effects of extremely low frequency magnetic fields found on cytotoxic activities and cytokine production of human peripheral blood mononuclear cells in vitro.
Sontag W (2000): Modulation of cytokine production by interferential current in differentiated HL-60 cells.
Mevissen M et al. (1998): Complex effects of long-term 50 Hz magnetic field exposure in vivo on immune functions in female Sprague-Dawley rats depend on duration of exposure.
Pessina GP et al. (1998): Pulsed electromagnetic fields enhance the induction of cytokines by peripheral blood mononuclear cells challenged with phytohemagglutinin.
Aldinucci C et al. (1998): Electromagnetic fields enhance the release of both interferon gamma and interleukin-6 by peripheral blood mononuclear cells after agglutinin stimulation.
Petrini C et al. (1997): Tumor necrosis factor alpha and interferon-gamma production by human peripheral blood mononuclear cells exposed in vitro to sinusoidal 50 Hz magnetic fields.
Pessina GP et al. (1997): Short cycles of both static and pulsed electromagnetic fields have no effect on the induction of cytokines by peripheral blood mononuclear cells.
Jonai H et al. (1996): Cytokine profile of human peripheral blood mononuclear cells exposed to 50 Hz EMF.
Cossarizza A et al. (1993): Exposure to low frequency pulsed electromagnetic fields increases interleukin-1 and interleukin-6 production by human peripheral blood mononuclear cells.
Cossarizza A et al. (1989): Extremely low frequency pulsed electromagnetic fields increase interleukin-2 (IL-2) utilization and IL-2 receptor expression in mitogen-stimulated human lymphocytes from old subjects.
Bersani F et al. (1989): Effects of extremely low frequency (ELF) pulsed electromagnetic fields (PEMFs) on immunocompetent cells. In vitro studies.