Study type: Medical/biological study (experimental study)

Effects of exposure to extremely low-frequency electromagnetic fields on the differentiation of Th17 T cells and regulatory T cells med./bio.

Published in: Gen Physiol Biophys 2016; 35 (4): 487-495

Aim of study (acc. to author)

To investigate the effects of a 60 Hz magnetic field exposure on T cells.

Background/further details

To elicit an effective immune response against pathogens, T cells have to differentiate into specialized types, so called subsets. Therefore, different subsets of CD4+ T cells (Th1, Th17 and Treg) and their markers were examined to get information regarding differentiation and signaling pathways.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: not given (probably during incubation, i.e. 72 h)

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Exposure duration not given (probably during incubation, i.e. 72 h)
Exposure setup
Exposure source
Chamber an exposure chamber was built using µ-metal in the incubator; chamber was ventilated via 2.0 cm holes in the upper and lower corners; holes had extension tubes of 2.0 cm to prevent stray fields; temperature was maintained at 37 ± 0.3°C
Setup system consisted of 4 square coils (each coil had 200 turns of copper wire with a diameter of 1.0 mm) and one area with three testing floors (top, middle, bottom); 60 Hz magnetic field was generated through one pair of Helmholtz coils, connected in series, each winding was split, allowing the current to flow in the same direction through each half of the winding (field adding); spatial variation of the magnetic field was <3%
Additional info no description given how unexposed cells were handled
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.3 mT - measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

In Th17 subset cells, gene expression of interleukin-17A and interleukin-17F was significantly elevated in exposed cell cultures when compared to unexposed cultures. The significantly increased expression of interleukin-17A was verified (protein expression of interleukin-17F was not analyzed). The phosphorylation level of SMAD3 was significantly increased in exposed cells compared to unexposed cells.
In Treg subset cells, gene expression of TGF-ß and Foxp3 was significantly increased in exposed cell cultures in comparison to unexposed cell cultures. To confirm this result, protein expression was also investigated using Foxp3-GFP transgenic mice and verified. An analysis via Western blot showed a significantly increased phosphorylation ratio of p-SMAD3/SMAD3 in exposed cells compared to unexposed cells. This elevation of Treg markers indicates an increased differentiation of T cells.
The authors suggest that exposure to 60 Hz magnetic fields of T cells promotes TGF-ß signaling and induces differentiation of T cells subsets which are related to this signaling pathway.

Study character:

Study funded by

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