Effect of Extremely Low Frequency Electromagnetic Fields on Expression of T-bet and GATA-3 Genes and Serum Interferon-γ and Interleukin-4.

This study investigated the effect of various magnetic flux densities of extremely low frequency electromagnetic fields (ELF-EMF) on expression of T-box transcription factor (T-bet) and GATA binding protein-3 (GATA-3) genes in the spleen and thymus of rats injected with human serum albumin (HSA). Moreover, serum levels of interferon (IFN)-γ and interleukin (IL)-4 were evaluated at two phases, that is, prestimulation and poststimulation with HSA. Eighty rats were separated into five groups, and four groups were exposed daily to 50 Hz EMF of 1, 100, 500, and 2000 μT magnetic flux densities for 60 days. To activate the immune system, 100 μg HSA was intraperitoneally injected into each rat on days 31, 44, and 58 of the regimen. Splenic and thymic T-bet and GATA-3 messenger RNA (mRNA) expression on day 61 was evaluated by reverse transcription quantitative PCR. Serum IFN-γ and IL-4 (in blood on day 31 before HSA and again on day 61) levels were evaluated by enzyme-linked immunosorbent assay. Expression of T-bet and GATA-3 mRNA was decreased in the spleen in hosts exposed to densities of 1 and 100 μT. Serum IFN-γ and IL-4 levels were also significantly decreased in 100 μT-exposed rats, but only at the prestimulation phase. From these findings, it appears that (30 and 60 days) ELF-EMF exposure could suppress the expression of some key genes associated with T helper (Th) cells and on some of their associated functions, that is, the ability to generate (in some cases, spontaneously) select cytokines. Whether this is attributable to effects on Th1/Th2 levels in the hosts and/or due to potential effects of the EMF on cellular functions remains to be determined.