Very low electromagnetic field and innate immunity in HaCaT cells

Defensins (DF) comprises a large group of host defence peptides. In recent years, the functions of DF as immunomodulatory and tissue repair agents have been widely investigated. Several evidences exists that electromagnetic fields (EMF) can influence both inflammatory processes andrepair mech- anisms on different tissue models. To study the effect of extremely low frequency EMF (ELF-EMF) on Anti Microbial Peptides components of the human innate immune system, human keratinocyte cell line (HaCaT) was exposed at 1 mT, 50 Hz and compared with unexposed cells at different time points (2, 18, 36 hours). Cytokines and DF gene expression profile were analyzed by polymerase chain reaction. Our preliminary results show that IL-1β and IL-10 cytokine expression were upreg- ulate after 2 hours of ELF-EMF exposure. However while IL-1β expression was not significantly influ- enced by 18 and 36 hours of continuous exposure, IL-10 expression was increased after 18h and returned to normal levels after 36 hours. Interestingly human beta defensin (HBD) 2 and 3 are unreg- ulated after 2h of ELF-EMF exposure. Meanwhile, only HBD-2 was sensibly decreased after 18h, with no significant variation observed at 36h. No differences were observed in HBD-3 expression at 18 and 36h. Simultaneously ELF-EMF does not seem to influence Vitamin D Receptor (VDR) expression in all investigated time points. These preliminary results may show that ELF-EMF mod- ulates cytokines expression in HaCaT cells. The upregulation of IL-1β could be responsible for the induction of HBD-2 and HBD-3. This could explain how ELF-EMF acts on tissue repair, at least in part, enhancing DF expression through a different pathway than VDR activation. More experiments are needed to better elucidate the actual molecular mechanism that induces the relative immuno- suppression and tissue repair enhancement determined by ELF-EMF